Unusual overheating issue
 

I have an unusual and perplexing overheating issue on my 96 Polo. I had Tom K. reseal my engine and give me back AWD, which I never realized I was missing since I didnt drive it this past winter. Anyway, all new oem subaru parts were installed, WP, timing belt, thermostat, etc. Temp was normal from Toms house until I reached NYC about 300 miles and noticed temp gauge was almost in the red. I immediately pulled over and let it cool down. There was no overflow at all. Upper hose was barely warm, and lower hose was even cooler, and rad. cap was cold. I had two 12oz bottles of spring water with me and put those in, and drove the remaining 100 home to CT. Temp was normal until I pulled in my driveway, and the gauge spiked to 3/4 with both fans running. I shut it off, and noticed some antifreeze blew out from the reservoir tank and under the battery tray. I continued to drive it for the last two weeks to and from work, and each day I would add about a half gallon of water total. I have about a 55 mile round trip, and temp is normal for about the first 20 miles of driving to and from work, then the gauge will suddenly spike to 3/4 to almost hot and quickly go back down to normal when the fans kick in. When I pull into the parking lot at work and in front of my house the gauge is 3/4 or higher with fans running and antifreeze boiling over from reservoir tank. I spoke to Tom about it, and I went ahead and replaced the thermostat which was defective with another oem thermostat and back flushed the system and I still have the same problem. Also of note, Tom had overfilled my power steering fluid and it was running down my timing cover and beading off of the oil filter. Tom thinks oil could have gotten under the timing cover and on to the belt and maybe slipping. I am not sure what to replace next, but I am about to remove the timing cover and see whats going on under there. Also during all this, my power steering is virtually gone, I need two hands to turn the car most of the time, and especially to paralell park or even turn onto a street. Tom did change all the power steering hoses and replace the o-ring. He also replaced the rad cap which is 13lbs, cause he said my old one did not old pressure. All I know is I had none of these issues before the engine was resealed with new oem parts. I drove the car witht AC on all the way from CT to Reading and no issues. I either have extremely bad luck or bought a bunch of bad oem subaru parts or both. All I know is I cant even enjoy driving my car, and to top that off I just got a speeding ticket the other night at 2:30AM coming home from work, talk about bad luck right.:(:mad:

Let's see, where to start....

1. You didn't say how many miles are on the engine, so I'm going to guess something like 100-125K (?) (edit, sorry didn't read your sig before for the exact mileage, so 160k+ miles makes the following even more likely...)

2. All the way from NJ to CT with a stuck thermostat could have very easily stressed a head gasket. The fact that both rad hoses were cold (classic stuck thermostat), nothing was blown back into the overflow, and you were still able to add 24 oz of water (did this actually fill the rad?) means the coolant could have passed a head gasket.

3. Taking it easy after adding the water allowed you to almost get home. I'm going to guess that maybe your driving got a little more spirited once you knew home was within sight. This would have raised the load on the engine/coolant system causing a hot gas pocket to form in the system which, in turn, caused the temp gauge to spike (been there, done that:o). Sorry, but flushing the system will not cure a blown head gasket.:o

4. Steering -- the SVX shop manual has an easy to follow set of steps to follow to see what is causing your problem. Have you checked the two fuses that are in the steering electrical system? Have you checked the output pressure of the PS pump? Have you checked the PS computer under the dash (it's bolted to the steering column)? My steering light came on on the dash when I lost power assist and it ended up being the PS computer that was bad (thanks to OT for a replacement!).

Hope this helps and best of luck getting back to enjoying your SVX.

-Bill

Anything out the exhaust? Have you done a block test?

My car did this as well after a long-distance trip. On my way back from San Francisco to Orange County, the car was rock-solid...until I stopped for gas just before the grapevine. As soon as we came to a stop, the temp gauge went up to about 3/4. I kicked in the heater to cool it down, the shut off the engine and went about my business. The grapevine went okay since we maintained a constant speed...but then when we hit gridlock traffic on the 5 freeway in Los Angeles, temperatures spiked to dangerous levels. I ended up putting the heater on constantly and switching the shifter to '1' to keep the revs up (and thus spin the water pump). We never went faster than 10 MPH anyway, so first gear was perfect.

We did make it home safe and sound, and after only about 10 minutes of cooling off I drove it to work without incident. And drove back without incident. Work is about 10 minutes from my house, and during normal drives like that, I've never had an issue. Short freeway drives are no issue also. But it seems that once you drive more than 100 miles, my car starts to dislike slowing down.

the fact that the hoses remain cold indicates there is a flow problem... This needs to be addressed first.

1. Pull the timing covers and reinstall the crank pulley. Be sure the water pump is spinning and never hesitates or stops.

2. Was the new thermostat tested to be sure it was working well?? A pot of boiling water on the stove with a laser thermometer will help you see what temp the t-stat opens and closes at.

This should, more or less, address the flow issue unless there is something larger lodged in the coolant system somewhere.

Also, while you are investigating, Check the simple stuff... Now you had mentioned that the overflow was not overflowing. A good way to check it is to see if you can blow into the tube and get it to bubble in the tank... If yes... that doesn't mean there is gunk at the bottom of the tank keeping the coolant from returning to the radiator once cooled down... So you also need to suck on the tube to see if there is blockage in that direction as well... While the idea of drinking coolant is not pleasing to many... There are vaccum pumps available if you prefer just don't use more than 16psi to pressurize the hose and probably close to 10 inches in mercury of vaccum to try and vaccum test the overflow...

Check these things and report back.

Tom

Good advice.:)
I did replace the water pump, thermostat, thermostat gasket, both bypass hoses with new parts.
(As well as reseal the oil pump and cam seals and cam caps.)
If I did not replace the upper and lower hoses then they seemed to be in good shape.
When I checked the radiator cap it held 0 psi.
We replaced the rad cap just before you left with a brand new one.
The power steering pump that was leaking at the cap continued to leak for a week after you left, which tells me that the fluid is being pumped out by the rack.
As of our last conversation reguarding the overheating, and water temperature spikes...
I wonder if the old rad cap, not being resistant to pressure, allowed head gasket leaks to pass into the atmosphere, past the original cap, while a good cap traps the escaping pressures, allowing an air pocket?

Wouldn't that air pocket then pass into the overflow, though? Anything beyond 13 psi flows out that way, so...

Even if there was an air pocket in the radiator... It drops the density of the environment allowing the coolant to boil... Thus the heat spikes... If the old cap didn't hold pressure it allowed the air and all expanded coolant to escape. Granted the boiling point would be lowered as well with a bad cap... it might have staved off any overheating.

Tom

the air pocket thing...
 

doesn't sound right to me:confused:
Just don't think it fits...
(But I could be off base here:lol:)

Keith

What do you mean??? When the EG33 loses a head gasket it is rarely between coolant and oil jackets, more than likely to leak compression to the coolant system...Which creates a pocket of gas.

Tom

Repeat offense
 

Guys, I took the new rad cap OT sold me and put back on an older one. I started off on a 30 mile ride Sunday afternoon. It was a sunny 80 degree day. I put my AC on right from the start and drove about 8 miles to Costco gas station. No problems, temp gauge perfect normal range. I also sat in a long gas line for 10 minutes idleing with AC on and no problems. One thing I want to add, and I dont know if its related is the temp. of the air coming out of the vents. Initially the first 10 miles or so, the thermometer in the vent was reading 20 degree freezing cold AC, then it went up to 38-40 degrees which is in the blue colored optimal range of the AC thermostat I was using inserted in the vent. I thought that was strange, cause the temp never again got down to 20 even though I was driving 65-70 on the freeway the whole time. About half hour into my drive is when the temp gauge started to spike to 3/4 and it immed. goes down to normal. It repeats this scenario several more times, occuring every minute, and each time it stays in the 3/4 area slightly longer. I pull into my driveway with both fans running and gauge holding at 3/4 level. Shut off engine, open hood and notice boilover from overflow all under battery tray area. Both hoses are stiff and very hot, as is cap.:confused::confused: :WTF: is going on. Going to take timing cover off this week and go from there. Is it a head gasket, bad WP, etc. Im so annoyed by this issue.

I agree with this conclusion. I think an air pocket in the system is causing the coolant sensor to read increased temperatures.