Cooling(overheating) problem still!!!

[jimmyboy]

I have replaced the waterpump,thermostat, rear heater coil, assorted hoses, expansion tank cap, and burped it for about 36 hours, replaced temp gauge and injector heat senders and i still have the same problem. The gauge will peg out all the way to the right after just about a minute operation then return to normal. Then it will peg out again and then go back to normal. Most of the time the fill tank will boil over on engine shut off. Any thoughts, We are going to remove the radiator next. Then the front heater core. After that I will have a completely new cooling system. Oh yea, we also did the C02 test for Head leakage, no leak. I call her latte' because she makes a delicious frothy green concotion of the non toxic kind! Any additional thoughts or ideas would be greatly appreciated.

[weinerwagen]

I know its a pain Jimmy, I had the same issue on a 84 1.9 I bought from a guy in San Fran, the water pump was gone, the system was dry

It would run for a few, then the red lite started flashing. When I turned it off, I could hear the engine boil, the overflow would burp big time but the radiator was cool.

Either, you have air in the system, prop the front up, then prop the back of the van up, try and work it out, OR you have a water flow issue. No blockage?

Try burping with the engine higher than the front....see if you can work out the air, but letting it sit over night with the cap open...maybe,

[Randy in Maine]

I think you have air trapped in the engine from the cycling from "OK to HOT" as water get up to the temp sending unit and then goes away and the froth re-enforces that thought. That needs to be bled out. Follow the Bently manual for the correct manner.

I have seen people install a Prestone "flush and fill" kit in a strategic spot and use that to assist in the removal.

Of course I know nothing about vanagons, but usually that involves making the "bleeding point" the highest spot on the car with a floor jack, ramps or whatever. Even though hoses cost a bundle for this thing, make sure yours are both good and not leaking any fluid or air into or out of the system.

A leak down test would tell you more than a compression test.

[weinerwagen]

it's a pain sometimes to get that air out
but it SHOULD NOT overheat quickly, if the head gaskets are in tact

when it is STONE COLD!!!!!! open up the resivour, start the engine
if you see air bubbles that is a sure sign of head gasket leaking

being a diesel van owner,.,,,,I know those sort of troubles

[Larry_Seidl]

I'm also having some overheating issues but I believe mine is a clogged radiator, 250 k miles. I have bled my system and overheated many times though. For best results it seems to help by jacking up the front end of the bus. My 90 has a small bolt on the top of the radiator accessed by removing the grill to allow air to escape the system. I set the idle at about 3000rpm and whith the cap off (you can see the coolant pumping) in the tank. I'll open that vent and let the air out. If it's really hot you can hear the coolant boiling in the engine. I know that steam in the sytem can make the needle peg on and off. Also check for a plastic hose assembly with a small valve on the thermostat housing I'm not sure exactly what it's supposed to do but it can let ou or suck in air accordingly. Lar

[jimmyboy]

I think (I hope) we've got it. We replaced the radiator and it still is bubbling. We did a Co2 test inside the resivoir sp. when it started to boil and waalaa, Co2. However, it passed the leakdown test so tomorrow it gets new head gaskets and maybe rings too. Will let ya know how it pans out.

[weinerwagen]

its a pain to do rings with the engine installed

heads no problem, the only tricky part was the shims, making sure they stay where they are supposed to when you get the head back in place

[jimmyboy]

Problem solved, so far. It was a head gasket leak internally not externally, The engine did come out and the rings replaced and we noticed some marking on one of the pistons and upon further investigation a lifter was broken. It too replaced. Along with new rods. I'm ready baby! Latte is doing fine now and even recycles fluid from the overflow tank which it didn't do before. Thanks for all the tips. This even took care of the intermittent stalling problem and uneven idle problem it had.