Cold weather overheating

[G-reg]

Ok help me out here, I've been getting coolant out of the overflow when I warm up my 92 NA Leg. If I let it warm up enough the temp guage will settle just high of normal. If I start to drive it will continue to start to overheat further. I don't see any leaks, other than the overload. I'm pretty sure I should not be overheating while idling at 5 degrees F. I filled the system up with the coolant it had been puking and it was fine, I drove around @ normal temp. The upper coolant (return) line is not really hot when it is indicating the car is overheating. So I'm thinking my thermostat is freezing shut, and boiling some of the coolant. If you can read through the rant enought to give me some advice I'd appreciate it,

[THAWA]

Yeah this happened to me a few days ago, right after the first really cold night. The car "warmed" up but i got no hot air from the heater and i was over heating as well. Barely got where I was going, I was almost in the red again. At anyrate I'm pretty sure my problem is a combonation of bad thermostat and waterpump. I'd check the thermostat first though since you said there was no leaking.

[haru182]

I realize that this topic hasn't been posted to in a while but no sense in making a new one. I HAVE HAD this happen so many times.....maybe 5 or 6 to be exact. I live in the upper penisula of michigan so its fucking cold here. I also lose heat and have it overheat. Outside of that I have noticed that I have no heat unless I am pressing the gas. Does anybody have any clue what could be causing all of this? ??

[evolutionmovement]

I had the exact same problem a couple times last winter, but it hasn't happened since. I think its caused by air in the system. I thought it was a weak rad hose closing at high speeds, but I haven't changed it and haven't had a problem in over a year.

Steve

[THAWA]

my problem was blown hg's

[evolutionmovement]

Oh mine only did it over 85 for twenty minutes or so and went back to normal as soon as I slowed down. Did it twice and I did have low coolant. Forgot those details.

Steve

[ciper]

BHG

[andrew.anderson]

Any of you figure out your actually overheating problem? I am experienceing similar issues with my MY99 SUS (engine EJ25d) and am looking to see how others have resolved their overheating problems in the past.

My car overheats randomlly. Hot outside, cold outside, driving 90 mph or driving 25 mph, long distance, short distance, doesn't seem to matter it will overheat under any of these conditions and then will not overheat for weeks at a time.

Maintenance background: Flushed the coolant and replaced it with new, did pressure check on all four heads, replaced thermostat, checked for leaks. Still overheats. I guess the waterpump is next. Problem is it will go weeks without overheating. Might have to give in and take it to a dealer. My warantee just ran out 3k ago. Imagine that 100k warantee and I start having issues right after it expires.

[THAWA]

as I said above, and ciper aswell, the problem was headgaskets.

[andrew.anderson]

Thawa,

Thanks. As I said I did a compression check already so that elimates that one from my list. Thanks though. It's nice to see that people still check this thread even though it is so old.

I am going to try to flush the air out of the radiator again. Hopefully that fixes it.

[G-reg]

I think my problems were because I didn't have a ND dose of antifreeze in the coolant. Even though it tested to -35 I think it was freezing in places and not letting water flow for a few minutes and cooking the water where the temp sensor was. Making the antifreeze to water ratio more like 70/30 helped.

[94L_wagon]

Andrew,

Did you undo the bleed screw in the top of the radiator when you topped it up? Also did you run it with the cap off until it warmed up and squeeze all the air out of the upper hose a few times, then top up again?

Intermittent problems you describe sound like air is trapped in the system. Other than that you might have an intermittent fan problem. Sometimes the motors wear so they will not start in certain positions. Next time it does it, pull over pop the hoods and check to see if the fans are going...

Dave

[Dr Nick]

I've just fixed this. Same symptoms - no heat from heater (on 60 mile run! - cold...). Next day top hose to rad exploded. Put it into the garage.

They diagnosed a failed sensor. The likes of Josh, vrg3 etc will confirm but apparently there's one sensor for the dash gauge and one to control the fan etc. The fan one had burnt out. However, when they replaced it the car overheated periodically for no apparent reason.

Flushed through the rad, new sensor, hoses replaced, waterpump done - still the same problem. Ultimately it turned out to be the thermostat that was the problem.

Sorted!