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The Truth About Coolant and The Vanagon Cooling system.

February 6, 2015 56 Comments Cooling Ken Wilford

Many are the horror stories that have gone around the internet and in forums about the dreaded Vanagon cooling system. If you believed all of them you would sell your van and run away screaming. VW had many problems with headgaskets and heads back in the 80s and early 90s primarily because most of the coolant that was sold out there where normal people would buy it (NAPA, Kmart, etc) was hostile to the aluminum, cast iron, rubber, and steel sandwich that is the waterboxer engine. However today every bottle of coolant I pick up says that it is based on Ethlyene Glycol which is aluminum friendly. Head problems can still occur but they are much less frequent and you can help avoid them for long periods of time if you do a couple of simple PMs.

One is to keep an eye on your coolant level. There are two reservoirs on the Vanagon for coolant. One is behind the license plate door (reservoir) and the other is inside the engine bay (expansion tank). You should be checking your coolant level every time to fill up with gas. If the level stays steady then you are fine. If the level is dropping, and you have to keep adding coolant then you have a leak somewhere. At this point you should start looking for the leak. I have a great tool that I got from Sears that allows me to pressure test the coolant system. You can make your own out of a small bicycle pump with a gauge on it and a length of rubber tubing. Attach the tubing to your pressure cap on the expansion tank (it has a small nipple on it). Now pump up the pressure to around 14 psi. Does the pressure hold steady? If not then it is leaking somewhere. Usually you can hear a hissing noise or see some drops starting to form. You have found your leak and now you can take steps to repair it properly. However some times the leak is very minute and it is actually seeping around the head gasket while the van is driving down the road. You should still be able to see evidence of this by removing the metal plates that cover the push rod tubes on each side and looking at the head gasket from below. If you see some coolant colored stains around the rubber gasket then you have a seep.

When you have a seep instead of a leak you may be able to delay doing a full head gasket job by adding some leak sealer to the coolant. Bar’s Leak or Aluma Seal are both good brands that can stop your seeps and stop your coolant loss. If you have a leak (dripping while the van is running or a puddle after you shut if off) then I would recommend doing a head gasket replacement. If you have a seep (just a stain on the head along with small coolant loss) then the leak stoppers are a very cheap thing to try and they won’t hurt anything.

Antifreeze restoration

One other advantage of Bar’s Leak (besides it’s seep stopping ability) is that it also contains additives that renew your coolant’s corrosion resistance properties. Many people don’t know that coolant breaks down over time and loses it’s ability to stop corrosion. Every couple of years you should renew the corrosion inhibitors in your coolant. You can do this by dumping in a bottle of NAPA coolant restore, or Bar’s Leak or flushing the entire system and renewing with new coolant. I like the first two ideas best because they are simple, cheap, and easy to do (that means most folks will do them). If you go with the coolant flush and refill I would recommend buying the premixed coolant from Prestone that is 50/50 mix from the factory. Or if you go with the blue goo (VW antifreeze) then only add distilled water to it for your mixture. Minerals in the water can cause chemical reactions in the coolant system and you don’t want that.

Visually inspect your coolant hoses and pipes. Just take a look at your hoses and coolant fittings every so often. Do they look good? Or do they look funky? Inspect the long pipes that run under the van. If they are metal (older vans) are they rusty? If they are plastic check the ends where they attach to the hoses. Does it look stange on the end? It could be that the end is separating and the pipe needs to be replaced. What about the other plastic and metal fittings on the engine? Do they look OK? Any plastic part that is original should be replaced at this point. They have a lifespan and it has been exceeded by several years. If the part is metal and not rusty then it should be fine to leave it alone.

Coolant Temp and light

Your coolant temperature is important. Too high and it can cause an overheat. Too low and it can cause your van to get poor gas mileage. The gauge is not calibrated but a properly working system should see the needle around the middle area of the gauge. If the coolant light is blinking you should pull over immediately! This light tells you that your level is low or that your temperature has gone to high. Driving a Vanagon with low coolant even a short distance can cause severe head cracks and gasket problems. This translates into thousands of dollars for that short ten mile drive that you “had” to do after the light started blinking. I would say that is the most expensive trip you will take and you want to avoid it. It is better to be safe than sorry. Yes the light could be giving a false alarm for some reason but is it worth it to take that chance?

Radiator fan

Your radiator fan has a low speed and a high speed. Many times the resistor can burn out so that you only have the high speed. This allows your temperature to go higher than it should and then the fan is cycling on and off way more than it should putting a strain on the coolant system as well as the electrical system. Test your low speed fan and be sure it is working. If you have Air Conditioning you can test the fan by simply turning on the A/C. As soon as you turn it on the low speed fan should come on. If not then you should test the low speed at the fan switch on the lower driver’s side of the radiator. Unplug the plug on the switch and you will see three prongs. In the plug, use a short piece of wire to jumper two of the connections together. This should give you one speed. Now jumper the plug another way. It should give you the other speed. If you can get the high speed but not the low then you may have a burned out resistor (86-92 Vanagon only) or a bad fuse or wiring (83.5-85 Vanagon). I keep the resistors in stock if you need one because I find that (because of age) many times they have failed the owner doesn’t even know.

Copyright Van-Again 2015

Comments

Ken Wilford October 22, 2017

Kurt, the first thing you need to figure out is if the van is actually overheating, or if you are just getting a false indication due to a problem with the coolant temp gauge system. It is very possible that your van engine isn't overheating, and that there is a wiring or sensor problem causing a false indication. You would want to check actually coolant temperature readings with an infrared heat gun at the radiator to confirm what you are seeing on the gauge, is actually what is going on. If you are experiencing boiling coolant, or overflowing coolant along with the temp gauge readings being high, then you do have a problem. I would guess that the problem is being caused by a blown head gasket! Yup. Even though the shop replaced everything with new parts, there is a chance that they could have damaged an o-ring at the top of the cylinder when they were installing the heads and now you are getting exhaust gases into the coolant even though everything was just done. You can confirm this by using a test for exhaust gases in the coolant. Your local NAPA sells a block leak test kit for around $45 or they are also available on amazon for a similar price. It involves a color change in blue liquid to see if you are getting exhaust gases into the coolant. If you are, no amount of bleeding will fix this problem. Did they use a Bentley Manual when they were doing the head gasket replacement? I would ask to see it at the shop. If they don't have one, then ask what reference material they used when doing the gasket replacement. If they look confused, you kind of know what happened. If the gasket was damaged on install, it is the shop's responsibility to fix it correctly. A exhaust gas test to confirm this should bring this to their attention. As always if you need anything parts wise, please support us in this way. That way we can be here in the future when you, or others need our help. Ken

Kurt October 21, 2017

I recently had the heads replaced on my 86 2.1. I had no overheating issues before...except when the head cracked and I had to replace coolant every 1000 miles or so, when the temp light started blinking. Finally had the money and I recently had the heads replaced. Now I can't get 10 miles down the road without the temp light flashing. I had my mechanic do the following. And he's a VW guy with Vanagon experience. Albeit, not much Vanagon experience: Replaced radiator. No change. Replaced the fan. No change. Replaced thermostat. No change. Replaced heat sensors. No change. All that's left are the coolant pipes? Right?? As I mentioned, these guys have worked on Vanagons. They know how to "burp" the system, so to speak. I had the small block rebuilt 20K miles ago by an expert that is now retired. So he's out of the picture. I have new AMF heads. And a Vanagon I currently can't drive. I hope you can point me in the right direction. :-) Thank you, Sir!! Kurt

Ken Wilford October 4, 2017

It sounds like you haven't fully bled the air out of the system. Are you bleeding at the radiator? Did you raise the front of the van? Do you have heat coming from your front heater? I need more info. Ken

Ken Wilford October 4, 2017

It could be the head gasket, but I would suspect the radiator first. They get clogged up from sitting with antifreeze in there. After a while it breaks down and allows corrosion. If the engine sat for 17 years this is a definite possibility. You can use an infra red heat gun to check temperatures at different locations on the coolant hoses and at the radiator itself. If you don't see the radiator getting hot while the engine is, then it isn't flowing and should be replaced. I have all of the parts to install the new version of the radiator into your 82 Vanagon. It isn't cheap but a new radiator may just fix your problem. Ken

Emily September 30, 2017

Hello I have an 82 vanagon, It had been off the road for 17 years and had no engine when I bought. I have installed a diesel 1.9 turbo JX motor, the van performs fine at low speeds however if you push it to 45 - 60mph then the temperature shoots up no blinking light though. Coolant travels from the reservoir to the expansion tank and doesn't seem to make it back, cap has been changed but it still spits the coolant out until the reservoir doesn't have any coolant in. Has had a new thermostat fitted that opens slightly earlier at 80 degrees for faster flow. New water pump was fitted when cambelt was changed before the engine was installed. The engine was in another van before this one and performed fine. I am at a loss for what could be causing this. Possible head gasket?

david September 28, 2017

hi i have a 1985 vw t25 1915cc petrol i drove it 600 miles and it was fine,then i drove it about five miles and noticed there was water pouring out of the radiator,there were holes everywhere on it,i have changed the radiator and tried bleeding the system but it is now overheating badly the temp guage is going right up i have checked the oil and there is no sludge or anything to suggest the head gasket is gone, i am new to vws and am not mechanically minded can you help me please

Aaron Nelson September 14, 2017

Many thanks. Really appreciate your down to earth approach to things (and the coolant hoses I recently bought)

Ken Wilford September 13, 2017

The Prestone is phosphate free. I use it all the time. Hasn't been a concern since the late 90s. Outdated information. Ken

Aaron Nelson September 11, 2017

Hi Ken, I just topped up (after changing a bad coolant hose) with a mix of ordinary Preston and distilled water. I now see that some (Go Westy and others) recommend only using phosphate free coolant. I don't believe that Preston is fully phosphate free. Should I be concerned?

Ken Wilford August 17, 2017

I am having a similar problem with a customer's van. His is an 85. I installed a new temp sensor, then a new wire from the rear to the front. The wiring goes through the coolant level warning system though and I think this is what is messing the signal up. I tried installing a new coolant level warning relay, that did nothing. I thought about bypassing the relay and going directly to the gauge but I thought it might make the light blink all the time. After doing all of this the gauge now reads at the edge of the white strip when it is fully warmed up. That is better than before when it would barely budge off of full cold when fully warm. I am still working on this problem, so if you come up with a solution let me know. I tried swapping in another instrument cluster which was a good working one, and it did the same thing so I am pretty sure it is still a wiring issue (under the dash).

Michael Dillon August 16, 2017

Hi Ken. I have a faulty temp gauge i have checked the gauge by shorting at fusebox and at sender connector both resulted in the needle going to the right. Ive replaced sender still the gauge only moves about 3ml. Any ideas please

Ken Wilford August 16, 2017

The 86-91 Vanagon 2.1l coolant system will basically self bleed over time. So I don’t really think the bleeding is the issue. You still need to bleed if you do major work or lose lots of coolant, but if you have a smaller loss like the rear heater, and you bleed it once, you should be fine as the air will leave the system over the next couple of days. Just top off the tank in the rear and you should be good to go.

Ken Wilford August 16, 2017

Tyler, you want to test the radiator fan to make that is working on both speeds. Usually the low speed fan resistor has gone bad and that is allowing the engine to get hotter before the high speed fan is coming on. Once you get both speeds then you can evaluate if there is additional damage that has been done or not. The 86-91 Vanagon 2.1l coolant system will basically self bleed over time. So I don't really think the bleeding is the issue. You still need to bleed if you do major work or lose lots of coolant, but if you have a smaller loss like the rear heater, and you bleed it once, you should be fine as the air will leave the system over the next couple of days. Just top off the tank in the rear and you should be good to go. Let me know what you find out with the fan speeds.

Elias Rivera August 7, 2017

I have a 1989 Vanagon. The temperature gauge raise a little over the light in the middle of the scale. This happens a few time ago and remains. I don't know if I'm bleeding the system correctly. Can you hep me to solve? (The heating system was eliminated because a leak.

Tyler Sherman July 27, 2017

Hi Ken, I recently took out the rear heater core on my 1985 country homes camper after it blew and flooded the inside of my van with hot coolant. Following the by pass repair,I slightly lifted the van with a floor jack to add coolant and bleed the system. Upon my test drive, the fan turned on once, but not until it was almost above 3/4. After this one time the fan would no longer turn on and temp needle will go straight to the top will red light flashing only once it exceeds 7/8. I'm not sure but i think that when the fan did turn on that it may have only turned on for the secondary stage. Van used to operate with the temp needle at just below the light, it now runs with the needle smack dab in the middle.I am going to check the switch like you have noted above. A couple things to note. 1) rear heater core was stuffed with pasta, yes, pasta. 2) Upon this discovery, is it possible that my radiator and front heater core are of the same fate and it is time to check and replace them? 3) When is it time to just call it and rebuild the engine with all new cooling hoses too. Slight head leak on drivers side but engine has good compression.

Ken Wilford July 16, 2017

Randy, sometimes the coolant level isn't full to the top in the expansion tank (the one you have to remove the engine lid to see). Folks fill up the one behind the license plate and think, now the system is full, but the other tank may be a little low. It can cause momentary low coolant level that the sensor is seeing and causing the light to blink at certain times. Usually it is when you first start up the van, and then it turns off because the coolant expands as it heats up, or more of it is sitting in the expansion tank because of how the coolant circulates in the system (probably the second). So if you want to be sure there isn't a low coolant issue, you need to open up the engine lid and look at the tank with the blue or black pressure cap on it. Is it full to the top? If so then it could be a wiring issue or a sensor issue. If not then top it off and see if this helps. Let me know what you find. Ken

Randy July 15, 2017

My Temp light blinks somtimes yet my coolant level and temp are OK. This has happened in all 3 Vanagons I've owned. Now I just ignore this blinking light. Do you this the sensors has gone bad?

Tony Lo June 9, 2017

Hi Ken, Thanks for your response and the valuable information. It makes sense, I will bring it to my mechanics for the repair since I don't have a lift to do the service. Should the engine compression improve after the head gasket replacement? Thanks Tony.

Ken Wilford May 31, 2017

Tony, a new head gasket and new head will fix the leak for sure. That is because the source of the leak is either a blown head gasket, or a crack in the cylinder head. There are no other ways this could be happening. Usually when you take it apart you will see the one cylinder that is having the problem. That cylinder will have the cylinder stuck to the head because of corrosion that is caused by the combustion gases getting into the coolant right there and creating a reaction. If you are having this problem your coolant is being turned into acid so you should deal with it sooner rather than later and also replace your coolant with brand new at the same time. Let me know if I can help you further. Ken

Tony Lo May 26, 2017

Thanks Ken for your response to my question above, however I'm still struggling with the same problem of having air in my cooling system. I found that I may have the same problem as Ken Krueger described above; combustion gas leak into the cooling system. I watched your YouTube video about cylinder head gasket replacement and got a good idea how to do it, however I have a question: How do I know whether a replacement will really fix the leak, how does the gasket seal between the cylinder and the head, just by the pressure applied with the head nuts? What can cause the gasket to leak? Thanks for any comment you might have. Tony Lo

Dan Durston February 26, 2017

Sweet. I know the one. Thanks!

Ken Wilford February 26, 2017

You want to pour it in the tank that has the blue or black pressure cap on it, that is inside the engine bay. Not the one behind the license plate, but the other one. Run for 30 minutes and you are good to go. Ken

Dan Durston February 25, 2017

Ken! You're a champ with this website. I've got some Bar's Leak but don't know where to put it in. I can't find the radiator cap. Looks like its up in the dash somehow. Can I dump the Bar's Leak inside the coolant expansion tank? Thanks! Dan

Ken Wilford January 26, 2017

The 83 Vanagon originally had a 1.9l engine. Does your instrument cluster have a tach or an analog clock (clock with hands)? Ken

Rina Heymans January 25, 2017

Hi can someone give me the cluster wiring diagram on a 2.1 watercooled 1983 volkswagen microbus?

Ken Wilford December 9, 2016

What engine and fuel injection system do you have? I assume a 2.1l waterboxer but I just want to be sure.

solly November 26, 2016

Hi test shows all good. I now sit with another problem. I drive it alot lately and yesterday as i stopped got out went into a shop came out tried starting it......nothing it just swinged.my mechanic says it can be that the history of the car makes the motor abit stiff. The kombi belonged to a church so basically serviced by VW. Please help

Ken Wilford November 22, 2016

I would do a compression test to see if the engine has good compression. That is a base line to see what kind of condition the engine is in. Then you can know what the health of the engine is. Let me know what you figure out.

Ken Wilford November 22, 2016

You should be able to top off the system and you should be good to go without draining anything. Ken

Ken Wilford November 22, 2016

Ken, I have had that test reaction too and if the fluid changes color at all toward yellow (which green would be a change) there is some sort of combustion gas leak into the coolant. You could try retorquing the head nuts since the leak must be small. I have never done this myself before but I have heard that it might work if this issue is a minor leak caused by slightly loose head nuts due to stud stretch or improper torque. The head nut torque is 37 ft lbs. If you torque it and it won't get to 37 ftlbs (doesn't seem to tighten up) then just stop because one of your head studs is failing. If the head nut torque is good then it is head gasket time. Let me know if you we can help you further.

Ken Krueger November 21, 2016

Hi Ken, thanks for your reply. Please forgive the lateness of my answer. Per your suggestion, I purchased the Lisle combustion leak detector and ran the test according to the instructions. The instructions for the leak detector said that if the color of the fluid changes from blue to yellow, then combustion gases are present. What happened for me was that the fluid changed color from blue to green. In addition to performing the test you recommended, I looked at the expansion tank cap (original, black, from 1985) and found a bunch of accumulated gunk in the valve that releases pressure so I elected to replace it with a new (blue instead of black) expansion tank cap. After bleeding the cooling system, I've driven the van a few times with the new cap. Thankfully, I've not had any more cooling system leaks but what happens is that coolant is pushed out of the expansion tank and into the overflow tank...sometimes completely filling the overflow tank. When this happens, I find also that the radiator has air in it. If I release the bleeder nut on top of the radiator when the system is still hot, allow time for air to escape, and then tighten the bleeder nut again, most of the coolant that was pushed into the overflow tank will be drawn back into the system. So it seems to me that there is slight leakage of combustion gas into the cooling system. Additionally, I've performed a compression test and three of four cylinders came up to 180 psi immediately. On the right side, aft cylinder, the pressure came up to 180 psi but it took a longer time of cranking the engine than with the other three cylinders. The oil dipstick does not have frothed oil (looks like chocolate mousse) on it nor is there any steam (white smoke) in the exhaust. The van has 168K miles on it and this is presumably the original engine. Thanks much for reading this lengthy response. Any thoughts, ideas, or suggestions are much appreciated!

solly November 21, 2016

Hi. I recently bought a van 91 model. The problem i have is as follows. I am from South Africa. My problem is az follows. It struggles to go over 100km/h. Its sluggish uphill. I have to gear down to 2nd up a 65 degree hill 250m long. Pleass assist.

Michael November 12, 2016

Hi Ken, just got the parts I ordered from you for the cooling system, thanks. I was wondering if I need to drain the cooling system? Here's my situation: Driving down the road, heard a pop, steam pours out of vents. Opened the engine compartment, to find the expansion cap had popped off, coolant in expansion tank is boiling / bubbling. I have decided to replace the expansion cap, coolant level sensor, thermostat and two 7mm lines that were cracked and greyed - (one from the expansion cap to the overflow tank, and one from the passenger side head to the coolant manifold). My question is, can I just swap out the parts and top up the coolant, or do I need to drain the system? Thank you

Ken Wilford November 1, 2016

Have you had the system tested for exhaust gases getting into the coolant? That is what it sounds like is going on to me. Here is a link to the tester which you can purchase through Amazon.com Block Leak Detector It should give you an idea of what is going on. If the combustion gases are getting into the coolant you will just keep chasing leaks in the system because it will fail at the weakest point. The system is only made to hold around 14 psi, so anything higher and things will start to pop. Let me know if this helps you out or how I can help you further. Ken

Ken October 30, 2016

I've had my '85 Weekender Westy for six months now and have been struggling with the cooling system. I have replaced the water pump, thermostat, all engine compartment hoses, the expansion tank, the rear heater core and the radiator. The rear heater core that I replaced only a few months ago ruptured and was replaced with a different brand rear heater core. The assumption at the time was that it was simply a poor quality part. Today I parked the car after running some local errands and noticed that the radiator (replaced only two weeks ago!) was leaking coolant. The temperature needle never went above the indicator light that is at about half range on the gauge. One item that has NOT been replaced is the expansion tank cap. Could it be that the expansion tank cap has failed such that it is allowing the pressure in the system to rise to the point that it is causing components like rear heater cores and radiators to fail? What is the maximum pressure that the Vanagon cooling system is designed to tolerate? If the expansion tank cap isn't the culprit, what would you suspect is causing these newly replaced components to fail?

Laura October 25, 2016

Hi thank you so much for reply any help appreciated . yes I'm getting motors from same supplier . AVP in California.originally through bus depot. . have been dealing directly with AVP. Who keeps sending me the engines. This has spanned 2 years of me not having my bus for any trips. And the inconvenience expense and stress unbelievable. 4th engine now... same thing as last one. Overheating at high speeds after15- 20 minutes of driving 65 -70 mph . my mechanic has replaced practically the entire cooling system. Radiator/ hoses tanks caps,switches thermostat,resistors. Tried to eliminate everything once again .. My mechanic and myself can't believe this entire mystery. I've been reading..forums again..... Only thing s I can think ofnow to try that hasn't been replaced are water pump and possibly catalytic converter. I'm just praying it's not the engine again. Any suggestions at this point. Thank you so much for your time . laura

Ken Wilford October 4, 2016

Are you getting your motors from the same supplier? Who is that? Is your mechanic bleeding the air out of the system at the radiator? I will try to help you out if I can. Ken

Laura October 4, 2016

HI KEN . IM SEARCHING THROUGH ALL SITES I CAN FIND . THIS IS MY 3RD ENGINE IN 1 1/2 YEARS . MY 2.1 1990 WESTIE VAN IS OVERHEATING AT HIGH SPEEDS ONLY... THATS JUST AT 65 AND ABOVE AND EACH TIME IT DOES , THE OVERFLOW TANK BEHIND THE LICENSE PLACE IS UP TO THE TOP SPILLING OVER . I HAVE TO WAIT TO COOL DRAIN IT FROM THE HOSE AND REFILL THE EXPANSION TANK PLUS ADD MORE COLLANT FROM THE BOILING BLOW OFF THAT OCCURRED DURING THE OVERHEATING EPISODE . JUST GOT ANOTHER REBUILT IN SAME THING HAPPENNED!!! AND TEST DROVE FOR 15 MINUTES AT 65 /70 AND SAME THING HAPPENED ......SO DISCOURAGED! THE ENGINE STILL GOOD AT THIS POINT PULLED IMMEDIAGTELY OVER .. RADIATORS BEEN REPLACED. HOSES SOME SWITHCES. ANY IDEAS FOR ME MUCH APPRECIATED MY MECHANIC AND MYSELF ARE AT A STANDSTILL CANT FIGURE THIS OUT . KEN ANYONE????

Ken Wilford September 25, 2016

Lucas, it would be nice to have a real temperature gauge on the cooling system just so you could actually see a temperature number. The gauges are really only for general ideas of where the temp is and some times the gauges can be not very accurate. The 84s have a problem sometimes with the level sender causing the gauge to go to full hot and the light blinks. This can be caused by actually low coolant level in the tank (expansion tank with level sensor in it should be completely full to the top when cold), or a wiring problem in the wiring for the level sender, or a problem with the instrument cluster (either the gauge or the foil being flaky). It can be difficult to troubleshoot but I would try a new level sending unit first, then check the wiring to the cluster with an ohm meter to see if it has good continuity. There is a connection in that black box that is on the left side of the engine bay firewall. Check the wiring color at the level sender plug and you will see the same wire color in that box on one of the cannon plugs in there. Check for continuity there to the sender. I think from there it goes to a level sender relay that controls the gauge and the blinking light which lives directly behind the left side front air vent that is closest to the door. Pull it and look straight ahead and it should be there. I am used to LHD vehicle so if they moved the fuse panel to the right side for a RHD Caravelle then maybe the relay is on that side instead. Let me know what you find. Ken

Lucas September 24, 2016

Hey ken, I have an 84 Caravelle and the temp gauge is sitting at just below 3 quarters high. The red light and gauge also fly's up and starts blinking at me every now and again but after driving a few more miles it stops and goes back to "normal". I constantly check the water, we have bleed it at the radiator itself, pulled the radiator out and cleansed it. (With a mix of coolant stuff and hot water and the whole thing heats up) and it's still does it. Any idea's will help!

Ken Wilford August 16, 2016

Have you tried jacking up the front of the van so that the tires come off of the ground an inch or so and then bleeding at the radiator bleeder screw? Also be sure your heater valve is fully on for the front heater. Rev the engine while you fill the pressure tank in the rear until coolant comes out of the bleeder screw on the radiator. Usually once this happens and you have a hot front heater core, you are bled out and good to go. Let me know if you need any more help. Diesels were the first year for the water cooling system in a Vanagon and that system is a little wacky. Even the radiator is completely different than the ones that were used just one year later. What could be happening is that you are getting the system bled but the radiator itself is clogged inside and not allowing for a good flow or heat transfer. The options are to take your radiator to a shop and have it recored (good luck finding a shop that still does this in your area) or getting a later model radiator along with the adapter parts you need to install it into your 82 from us. Let me know what you figure out. Ken

Ken Wilford August 16, 2016

Check the wiring from the front to the back with a meter. Does your fuel gauge also read low? If so it could be a problem with the voltage regulator for the instrument cluster. If not then it is a problem with the gauge itself or maybe the wiring on the back of the cluster. Let me know if I can help you further. Ken

Anthony calabro August 15, 2016

I have an 82 diesel. I just replaced the waterpump and housing and I am having a hell of a time getting it bleed properly. The tank in the engine bay is filled to the brim and the espansion tank has never been filled to Max since I bought it. Is there not enough coolant in the system and that's why I can't bleed it? Should I add more to the expansion tank and see what happens. The temp gauge usually runs incher middle at normal operation and climbing a hill it gets up to about 3/4. Is all this normal. I see a lot about gas waterboxers but nothing ever about diesels. Any thoughts are helpful thanks!

Jean-Francois August 14, 2016

Good day sir, the temperature gauge is not working on my 86 westy, the indicator barely moves when driving now. Checked the inside of instrument panel for dirt or corrosion , clean; check the level sensor , clean and working fine; check the wires on the temperature sensor ,clean but i get 5 volt when reading the multimeter; engine does not overheat and the fan kicks in when needed. it's just the gauge indicator refusing to get up there. Any ideas about this problem. Thank you. J.-F.

Ken Wilford July 12, 2016

Fred, the expansion tank (the one that is under the engine lid with the pressure cap) can be completely full to the top, no problems. The one behind the license plate is only supposed to be full up to the line that says Max. So if your expansion tank is full to the top, that is not a problem. If the overflow tank behind the license plate is filling up to the top, then you have a problem. Let me know if I can help you further. Ken

Fred July 6, 2016

Hi Ken, I've got the same problem as Tony. I did replace my radiator , been bleeding the system (hell of a job). When I went for a test drive everything seems to be okay : temp. goes up ; fan goes on ; temp. drops..so far so good. After the test drive checking the coolant level, reservoir level : top ; level expansion tank high and after cooling down the level in the expansion tank stays to high. I did try also an new original VW pressure cap and the level still stays to high. What I also found is that the when I was doing my test drive I did hear water running thru my heather, but the heather also gets hot. I looks like my WBX is going to ruin my holyday

Ken Wilford June 28, 2016

The only thing I can think of is that the temperature spikes after you drive for a while and then stop. If the radiator fan isn't working properly this could cause a temporary overheat situation when you stop to get gas and it is just enough for it to overflow a bit. So I guess you really want to make sure your radiator fan is working properly. Do the tests and see what you find out.

Cee June 25, 2016

Hi Ken, My 89 Westy leaks a little coolant for a short time after I fill up the gas tank. Any relationship to each other? Otherwise I see no leaks. Any thoughts on this? Otherwise I'll follow the problem points you've mentioned. Thanks.

Ken Wilford June 21, 2016

Kathy, what year van is it? Also what are you seeing on your gauge when this happens? Are you hearing your radiator fan coming on? Did, it start happening suddenly or is there some event that happened and now this is happening? Let me know more and I can help you zero in on the issue. Ken

Kathy Confer June 19, 2016

I have a problem similar to Tony lo. it gets warm in stop and go traffic and it overflows from the main coolant tank and temp sender unit. over flow tank stays at same level when this happens. What's the next steps to take?

Ken Wilford May 17, 2016

I would say the tank cap would be the prime suspect. We have new ones available and they aren't expensive. Take a look at the tank while you are at it. They like to crack between where the cap screws on and where the level sender is located. If it is cracked buy a new tank and it will come with a new cap. Ken

Tony Lo May 13, 2016

Hi Ken, I completely replaced all coolant hoses and the radiator on my 89 Vanagon once I purchased it in 2014, both cylinder heads and gaskets were also replaced due to leak. Now I have another problem, after I drive the van for a while the coolant gets to the overflow tank and does not return to the expansion tank after the engine has cool off, resulting in low coolant level in the expansion tank. Would this be caused by a bad pressure cap? Thanks.

Ken Wilford April 19, 2016

Mitch, usually this is just low coolant level. The light in the 86 -91 Vanagon will blink when the level is below the sensor in the expansion tank (the tank that you have to remove the engine lid to take a look at). Many folks just look at the overflow tank behind the license plate, but if there is an issue in the expansion tank (blue or black pressure cap), then this will cause the light to blink. If it is blinking at lower speeds that means that you are just at the low limit of coolant and the system is warning you of this. When the van is cold, remove the engine lid and check the expansion tank (to your left when looking at the engine from above). Fill this tank completely up to the top. Now put the cap back on and be sure the hose to the overflow tank is attached. Fill the overflow tank to the line and observe the level in the overflow tank over the next week or so adding coolant only after checking the level once the van has cooled down completely. If you have to continue to add coolant to the overflow tank for more than a couple of days, then you have a leak and should investigate further. If the coolant level stops dropping then you have a slow leak (probably a head gasket seep) and you might want to try some K-seal or bars leak to temporarily stop this. Let me know if you need more help.

Mitch martina March 23, 2016

Hey Ken,my 1986 VW vanagon temperature light came on and stayed on while I doling the other day but once I get up to like 30 mph it goes off and stays off until I slow down to like 10 mph or less then it comes back on and stays on till I get back up to a good cruising speed. Any ideas??thank you sir

Ken Wilford December 17, 2015

Tony, I would recommend a new cover and a new lower thermostat housing as they are both plastic and tend to get brittle with age. Eurovan one is completely different. If you have any other problems please let me know.

Tony Sudney December 16, 2015

Hey Ken bought a thermostat and an "o"ring from you. The son attacked the van and run into a problem. The bolts that hold the thermostat cover in place are rusted to the threaded inserts in the lower housing which is causing the inserts to turn with the bolts so that the bolts are not retracting, going to need a new housing. Is the cover for the Eurovan the same as the one for the vanagan?? Tony Sudney

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