Author Topic: coolant system problem (Read 4668 times)

w0nderpr0 · « **on:** May 02, 2007, 10:06:28 am »

I bought a 94 golf diesel (1.9l aaz motor) and it had the head blown. i picked up a head that had 100 hours on it for 250 CAD, and got all new gaskets and such. Put the head and everything back together the way the service manual said and double checking on here. Now the car ran fine for 300 km and then it started to overheat with the temp gauge going up to 110 when i would then pull off and let it cool down to about 70. did this twice more and finally got it towed home (never once went over 110). So i replaced the thermotsat and made sure the rad was flushed and water pump infact was pumping. all checks out fine but it back together and burped the coolant system and the car will not blow hot air out the vents with the cap on the coolant bottle. tryed 2 older caps and a new one no luck.....when the cap on the coolant system presurrizes itself up where the rad hoses are rock solid and cant be pinched with your fingers. when you release the coolant bottle cap (after its done pissing all over the place and shooting out water) you get heat out the vents. So i let it run like that watch little bubbles come up for an hour. temp never went over 85. put cap back on and same problem.,......i figure either the head gasket is screwed and i need to put another new one on...or there is one hell of an air lock.....what do you guys think. i even tryed without the thermostat to see if it was pumping water and the same problem of the system pressurizing itself....take off the presure and it seems fine

jtanguay · « **Reply #1 on:** May 03, 2007, 04:43:45 am »

i would test the thermostat.

the one i bought from vw opened slightly at 100 deg C... :roll:

i also suspect that the coolant lines for the heater core are mixed up... something doesn't sound right there... i was having some of the same issues as you, except i did have heat coming out of my vents no matter what.

hope it's not a head gasket issue!

w0nderpr0 · « **Reply #2 on:** May 03, 2007, 04:57:46 am »

there is no thermostat in the system right now to remove it as a possiblity.

two friends have 94 jetta and a 96 jetta with aaz motors and all tubes are right.

saurkraut · « **Reply #3 on:** May 03, 2007, 05:53:15 am »

Try letting it warm up with out the cap.

When its warm, put the cap back on.

If it builds pressure then, it has a cumbustion leek (blown head gasket, cracked head, etc.)

jimfoo · « **Reply #4 on:** May 03, 2007, 06:05:46 am »

Without a thermostat at all, isn't a lot of coolant just going to recirculate since the internal port won't be blocked off? I'd test it that way, but not drive it far at all.

jtanguay · « **Reply #5 on:** May 03, 2007, 02:02:59 pm »

yea i'm with jimfoo on that one... the thermostat regulates the amount of flow to the rad & engine... without it the coolant won't be going where it should..