2G How to get coolant temps down, all stock

[96ETT]

Ok so its another "my coolant temp seems too high" thread...

So I have only owned my 2g awd for a couple months and worked on it maybe 4 times total. Now that I had it driveable with AC and and everything I have been using it as a DD. The other day I noticed my temp gauge climb up and the check engine light came on from my ECMlink coolant temp setting (234 F). I cut the car off and coasted a quarter mile off the highway and checked it out. Noticed it was very low on coolant and a small rubber hose going to the oil filter housing was cracked. Limped it home safely and just replaced that hose and my thermostat because it was a cheapo one with no weephole.

So after replacing that hose and thermostat with a "failsafe" one, I filled it up and drove it around. It seems my coolant temp would stabilize at idle around 203 F but my fans would not turn on unless I gave it a ~15 degree offset. Then while cruising around they would sit around 225 or so. It is only 75 degrees today.

Also I can hear like a fizzing or bubbling coming from the thermostat housing after I shut it off just now, maybe air bubbles working their way out of the system? I burped it the best I could.

So we are down to possibly a fan problem or just some bubbles working their way out I think. Anything else to check or verify? I think my coolant temp should be around the 180 like the thermostat is rated for otherwise the thermostat is useless.

 

[92AWDHX40]

Well did you do a compression test to make sure your hg isnt blown?

 

[96ETT]

Well did you do a compression test to make sure your hg isnt blown?

No I have not, the previous owner had replaced the head gasket and head about 9 months ago. The head is still shiny. I doubt that would be it so havent checked yet. I would hate for that to be it, but I can try.

 

[UCF201101]

IMO I would just pull the spark plugs out and do a headgasket check really quick. IF that shows up as good, I would check to see if your thermostat is working. One way to check it is to take it out and place in a pot of boiling water. The fans should kick on at a certain temperature. I don't recall the certain degree but if its always kicking on at around the same number then you should be fine. Was the fans running will the car was heating up?

Daniel

 

[Bud92gsx]

Thermostat not opening would cause high temps and the cooling fan not to come on..Thermostat is literally a couple minute job, and couple dollar fix..

 

[96ETT]

Thermostat not opening would cause high temps and the cooling fan not to come on..Thermostat is literally a couple minute job, and couple dollar fix..

I just replaced the thermostat today...

IMO I would just pull the spark plugs out and do a headgasket check really quick. IF that shows up as good, I would check to see if your thermostat is working. One way to check it is to take it out and place in a pot of boiling water. The fans should kick on at a certain temperature. I don't recall the certain degree but if its always kicking on at around the same number then you should be fine. Was the fans running will the car was heating up?

Daniel

I will have to rent a compression tester tomorrow to do that. Also the thermostat is brand new today. The fans dont seem to kick on even at 206 F but if i give them some coolant offset in ECMLink then they come on.

 

[Bud92gsx]

So the only way you can get the fan to turn on is if you change something in link?

 

[1990AWD]

Is the radiator and condenser clean? If your not getting proper airflow, it will overheat really bad.

If you can, also do a leakdown test when you do a compression test and then its easy to tell if you are pushing coolant.

 

[96ETT]

So the only way you can get the fan to turn on is if you change something in link?

That is what is seems like, but I just did a 15 minute drive with the fans on all the time via link and it still gets hot. Seems like the fans dont do much to the temp. I know they both work.

Is the radiator and condenser clean? If your not getting proper airflow, it will overheat really bad.

If you can, also do a leakdown test when you do a compression test and then its easy to tell if you are pushing coolant.

Yes they are both clean, and it is weird that even if I run the ac it still only gets about 6 degrees warmer, but doesnt overheat. I will try and do a compression test tomorrow.

 

[BogusSVO]

234* is not over heating, if your coolent system is on good working order, and no leaks.

At sea level water boils at 212*

For each lb of pressure on the coolent system, you add 3* to boil over point

You should have a 13 lb rad cap

So 13 lb cap x 3* = 39*
212*+39* = 251* is your boil over point

Now 251* - 234* = 17* under your boil point

You need to find the spec on the fan sensor turn on point it may be around 240* to turn on

*** Tech Tip*** Rad caps need to be checked and/ or replaced every other year.

 

[96ETT]

234* is not over heating, if your coolent system is on good working order, and no leaks.

At sea level water boils at 212*

For each lb of pressure on the coolent system, you add 3* to boil over point

You should have a 13 lb rad cap

So 13 lb cap x 3* = 39*
212*+39* = 251* is your boil over point

Now 251* - 234* = 17* under your boil point

You need to find the spec on the fan sensor turn on point it may be around 240* to turn on

*** Tech Tip*** Rad caps need to be checked and/ or replaced every other year.

You know this is what I needed to read. This explanation is right up my alley. I was looking through some old logs from my 2g fwd I used to have, with a big 16g, FMIC, no ducting or anything, and it ran around 220 to 230 all summer long in south Texas. Right now I am running around 220 with no FMIC but also missing some stock ducting. I think when I put my fmic on I will duct it and seal it up and I should be fine.

I just read a lot about people with these cars running around the thermostat temp. I always thought you were supposed to run around the thermostat temp also, because if you are above it all the time it is just all the way open. At that point all it does is help you warm up quicker and then not needed I guess right?

 

[1990AWD]

While 220 is technically safe, it is higher than it should be. My 1g bone stock ran at a constant 203*F. It should be lower. When was the last time you did a coolant flush?

 

[DSM1G90]

..when was the last time you took the radiator out and flushed out all the crap that resides in that thing?

Also, you mentioned AC - now, that's gonna put a hefty load on the motor which will definitely cause it to get plenty hot. AC and 4cyl motors aren't the best wedding in the world to make.

Plus, is that the original compressor? If so, plan on replacing it for they begin to work harder than normal to eventually seize down the road when age gets on them. How is the compressor fluid in the compressor-oughta check that as well, for low fluid can cause the compressor to work extra hard and that definitely pulls HP (like almost 20hp) off the front of the crank. They pull 5 to 12 HP off the front of the crank alone just by being used normally...

These two factors could be the cause of your overheating. What does the vehicle do when you turn the AC off?

good luck - DSM

 

[MikeyTsi]

Make sure you test your thermostats before installing them, it's really easy to get one that doesn't work right out of the box. FYI, I was seeing overheating issues as well a few months ago (gauge would get to about 75% or so), and mine turned out to be a leaking lower hose and a cracked upper housing on the radiator. Keep in mind that the factory radiators use plastic end tanks, and those get brittle and shit the bed after a time.

 

[BogusSVO]

I just read a lot about people with these cars running around the thermostat temp. I always thought you were supposed to run around the thermostat temp also, because if you are above it all the time it is just all the way open. At that point all it does is help you warm up quicker and then not needed I guess right?

The thermastat is for warm up and to get you to op temp, a cold block wears faster than a warm block, also you get better power and more fuel effecient per unit of fuel.

A theremastat dose not just go from closed to open, or open to closed, it is a gradual movement based on water temp.

A 190* there will be fully open at that temp, so when your coolent temp is higher than 190* there is nothing the thermastat to do but remain full open.

Now infront of the car, you can have upto 3 or more heat exchangers, Intercooler, AC condensor, Radiator, oil cooler, PS cooler

No each of these will raise the air temp as it works back to the radiator, so you will not have the temp drop from the air passing thu all these coolers on the way to the radiator, and in turn this will cause the engine temps to rise.

 

[96ETT]

I have not flushed anything yet, just topped her off when I bought it. I do use the AC but the temperature doesnt change much. I usually run around 220 and with AC it is 225, not really any hotter. I did verify the thermostat is working. The gauge on the dash never leaves halfway. Like I said I looked back at old logs and for 2 years my other talon ran just like that with AC and everything and that one I did replace everything and clean it all up. I guess it is ok for it to run at this temp. I will still do some cleaning and that compression check and keep this thread updated, but I almost feel like its ok.

 

[DSM1G90]

If the needle reads right before the half line, you're doing fine. That needle position on the gauge is almost standard in all makes and types of vehicles.

Just shows that the system is running normally.

-DSM