Overheating questions

[Cesarlcase]

At one point I had a severe overboosting problem for like a month or 2... After i
fixed it, I noticed the car was running hot. Now I'm trying to figure it out but cant :/ If i drive at normal speeds, it stays cool for a while (not highway) but if i floor it for like 5-10 minutes the temp would go way up like 3/4 on the temp gauge. And when i eventually stop, the cooling fans will lower the temperature again. I've changed everything before on the cooling system from the radiator cap (16psi) radiator changed about 4-5 months ago (off ebay) new coolant, currently driving with no thermostat. When i first completely removed the thermostat, the car was able to drive at 70 mph on the high way at operating temperatures for about 30 mins. Only till i came to in town driving did the temperature start going back up. Now its the same as before just goes up after a few WOTS...but my fans do work. A lot of coolant comes out of the overflow hose lately. I figured head gaskets but i dont see any white smoke out my exhaust,nor do i see any coolant in oil vice versa. Could anything else out side the cooling system cause overheating? Thanks for your help.

 

[TSiAWD666]

Hate to say it but something in the engine is pressurizing your coolant. Buy/borrow a radiator pressure tester and hook it up cold to your where your radiator cap goes. Start the car and let it warm up. If you reach up to 15lbs. by just sitting and idling then you've got a combustion to coolant leak. I've read normally you shouldn't pressurize past 7 psi when just idling.

 

[Cesarlcase]

If the engine is pressurizing the coolant that's a head gasket leak right?

 

[dsmtalontsi95]

Almost always.

 

[TSiAWD666]

It can definitely be a head gasket, but also a cracked block or head. I have had a hard time finding specifics on the latter two scenarios on just how they manifest.

I was looking for this info because I had the same scenario. I went through a head gasket replacement and I still have pressurized coolant I either f'd the head gasket replacement somehow (perhaps block was warped too and/or I didn't get enough of the old gasket off?), or I've got a crack in the head or block. At this point I'm giving up on this old engine and looking at a 2.3l or 2.4l to just move on heh.

I hope in your case it's just a headgasket leak! I don't think there is any way to know which it is without removing the head first to look.

 

[Cesarlcase]

Just curious but today I was driving and i drove pretty far like 15 miles with my car (had no choice) but i put the Heater on and it stayed cool the whole way there even at w.o.t Where the temp gauge would only go up like a tad than when i released off the gas for a few seconds its would go back to operating temperatures. There is no more coolant coming out of the overflow, with this new fact is this still indicative of there being a head gasket problem/block? I have no white smoke or any of the usual symptoms of head gasket damage. I just want to make sure i get it right the first time.

 

[MIdsm]

After the engine has warmed up you ought to have hot air coming out with the heater lever turned to hot. To me that indicates that the coolant level is too low and heater core has never been filled. After you replaced the head gasket did you run the heater at full blast when you re-filled the coolant? You are also supposed to "burp" the system of all the remaining air. Your symptoms indicate air in the system.

Now whether the problem is due to a blown head gasket or just incorrect fill procedure I couldn't tell you. The first thing I would do is to fill the system with coolant and burp it and then drive for a few days and see if you are loosing coolant. The ECT sensor will give a false reading if it's in the air vs. coolant. Low coolant level could cause some parts of the engine to overheat but you would have no idea as the gauge wouldn't indicate a problem. The water could turn to steam in one spot and raise the system pressure to the point that some water may be pushed out. You could and should do a coolant system pressure test, a compression and a leakdown test.

Good luck.

 

[nek]

Isnt the system supposed to pressurize? Isnt that how the overflow bottle is used, it opens at a certain psi? Or is the overflow not supposed to be used unless a last resort.

 

[2GRick]

Just curious but today I was driving and i drove pretty far like 15 miles with my car (had no choice) but i put the Heater on and it stayed cool the whole way there even at w.o.t Where the temp gauge would only go up like a tad than when i released off the gas for a few seconds its would go back to operating temperatures. There is no more coolant coming out of the overflow, with this new fact is this still indicative of there being a head gasket problem/block? I have no white smoke or any of the usual symptoms of head gasket damage. I just want to make sure i get it right the first time.

Make sure all you small coolant lines are not plugged or kinked etc. A lot of people only think about the radiator hoses. Did you fill the radiator with the heater woking. A lot of people forget to do that (even garages....asked me how I know) Did you check to see if your coolant line to the turbo is plugged. That would deffinately cause the turbo to get hot. You could be running lean also. Hope this helps.

Just read on another forum where someone had the exact same problem !!!!!!!!!! The solution was to re torque the cylinder head. It's free and easy to do.