1991 Jetta 1.8L Carat Overheating, mystery....

First off, thanks to all of you out there helping so much. I've learned so much from all the people posting on this site. I really try to dig up the information before I post....now, onto the car..

I recently learned (thanks to this thread) that when you flush your radiator/system you should use a funnel and pour liquid into the radiator, so that the thermostat gets hot enough to open and circulate the liquid. Thanks so much for that advice! That really helped me out...now, more problems...

After I had found out my ignorance in refilling coolant, I saw that the needle was behaving normal and eventually made it to the center where it seemed content. The engine fan came on when it got a tad hotter. This was good. The coolant system was working! I was thrilled! I went to the vehicle testing place, and low and behold, my coolant was so hot it was boiling through the expansion tank and my car effectively pissed green all over the emission testers good boots. I sheepishly grinned and took my poor wounded VW away from their scowls (maybe my car has an aversion to authority figures...). To make matters worse, the engine got further hot and the engine oil light came on and that famous buzzer too. So now I have two overheating lights coming on, and now the fan wasn't coming on anymore (probably because the coolant was long gone?) It seems as though the coolant had somehow failed to circulate properly through the system! I rewired my fan to the fuel pump (temporarily) to stay on while I drove my injured VW home. The smoke from burning oil came from my engine slowly creeping me out at all the intersections (man those red lights seem to take FOREVER!!) The temp guage was at this time just past the mark to the right of center. The buzzer stayed on almost constantly with a 10 second break on the highway.

All the hoses are hot to the touch, which I have been told is no sure indication of thermostat failure. (I would have already changed the thermo, but the strange location of the thermo seems challenging)

Also, when I squeeze the upper radiator hose, I get little resistance (supposed water pump pressure test) compared to my friends Honda which is very hard to squeeze.

When I had refilled the radiator after my proper refill, I got some chattering noise on the belt that connects the power steering pump pulley to the (a guess)???waterpump??? perhaps the waterpump is toasted? What is the other device connected by belt to the power steering???

The final strange clue is this....when I open the coolant reservoir tank (engine running hot), the coolant doesn't seem to circulate (if indeed it is supposed to in the first place), it just seems to suck all the liquid into the bottom (probably into the radiator), then it comes back up, boiling and steaming and frothing all over the place. Then it gets sucked in again and repeats the process every 30 seconds or so.

I have put so much time into this car by now, and this overheating baffles me. I wish there were surer ways to test various parts of the coolant system. Any VW sleuths who can point me in a direction? Thanks for any of your imput (sorry this message was so long too...)

-Thomas

Reply to
Thomas Kadlecek
Loading thread data ...

Jim B.

Reply to
jimbehning

Man I hope that it isn't the engine!! I tried to not drive it for very long or very far in the heated state. I havn't seen any oil in the coolant. I am seeing if the thermostat is working at the moment. I have it in a pot of boiling water....it looks like it is working fine. So either my water pump is toast, the radiator blocked (doubtful) or my engine is in trouble. Any more suggestions??

Reply to
Thomas Kadlecek

Okay folks, here's the latest (for those of you tuned in...), I "THINK" that I have this figured out. Filled up system with coolant again and turned on vehicle. After engine warmed up and thermostat opened, coolant coming out fluid reservoir tank....screwed on pressure cap at same moment (I have a penchant for the dramatic) and "whalla!" no pressure from the cap to the system, coolant draining out the drain valve.

What have I learned?

Not to tear apart the entire car, until you have verified that the thing is under 17 PSI in the first place!!! Yikes!

Live and learn and learn again.

That's the way of the novice mechanic.

Reply to
Thomas Kadlecek

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.