McN

Hey,

I have a temperature problem with my G20 5.7 TBI and unfortunately, I cannot for the sake of me, find out what the problem is / where the problem could be coming from. I changed the thermostat and the coolant yesterday because the engine never really got warm and also because the wrong antifreeze was in there. The temperature gauge did not move at all and the air from the heater was only lukewarm after longer drives. When I removed the old thermostat, I noticed that it wasn't put in correctly (see attached photo - the big ol' gap). The previous owners ONLY botched it up (sealant instead of gaskets and they even used sealant to isolate wires) and therefore, I wasn't surprised about that at all. I tested the old thermostat in hot water and it opened and closed as it should. I did the same with the new thermostat before putting it in. Today I went for a drive and was happy to see, that the engine finally reached operating temperature and that I had hot air from the heater.

After driving over the back roads for about 10-15 minutes, the fun was over...the temp gauge went to the red zone. I quickly stopped, turned the engine off and let it cool off for about 20 minutes. I wanted to drive back home but couldn't get there without taking 2 more involuntary stops because it kept getting too hot. After the van cooled off, I checked the coolant level and the radiator is full and the level in the expansion tank was the same as always. The upper coolant hose is getting hot after the thermostat opens up. I drilled a little hole into the thermostat before installing it, which helps with the bleeding. I also bled the system for about 40 minutes and there are no bubbles coming out anymore.

Now there's another problem. It is smoking like crazy out of the exhaust (white smoke), even when the engine is already warm. I know that this could mean a blown head gasket but it's not losing any coolant and it's not consuming oil. A CO2 leak detector test showed no signs of fumes in the coolant. I also did a compression test and all cylinders have a compression of about 150-160 psi / 10 bar. There's no noticeable variation between them. If I had a blown head gasket which would be the cause of the white smoke, I should have at least one cylinder with (significantly) lower compression, right? It absolutely does not smell like anti freeze though, it rather smells like unburnt gas. The fan is working and I also checked the fan clutch. I also checked the trouble codes and I only get a code 32 (egr circuit). A new EGR valve should be here by Wednesday.
Here is a short clip of the smoke:


Maybe the previous owner poured water into the tank instead of gas
This van has caused me some sleepless nights since owning it for sure. It would be really great if some of you might have any tips which could help me solve this problem.


old thermostat