The Truth About Coolant and The Vanagon Cooling system.

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