Thermostat and operating temps

[GRace]

A few months ago I installed a new stant fail safe 190 degree thermostat. I recently got the new motor installed with the same thermostat and I am running around 210 degrees in town and about 215 or 216 on the highway.

Is that too hot for our engines to run? Is it time to install maybe a 180 degree thermostat? I have a newer aluminum radiator and new water pump. Any ideas would be appreciated!

 

[1990AWD]

Ya that's a little too warm, with a 190 thermostat, you should expect 195-200 temps all day long, unless its stupid hot outside.

What do you have for fans/shrouding with that aluminum rad?

 

[gofer]

Pull 1 degree timing :: 206F (97C)
Pull 2 degree timing :: 224F (107C)
Enter Open Loop Mode :: 228F (109C)

Pop the radiator cap and start the car, while its idling try burping the coolant system by squeezing the lower radiator hose (add coolant as necessary). Just watch your hands on the radiator fan and the exhaust parts, both can bite you if you aren't being careful.

From your symptoms (hotter coolant temps cruising and not at idle) it seems there could be just air in the lines, which is easier and cheaper to take care of than replacing a t-stat.

 

[GRace]

It was just a stock replacement radiator so I'm using stock fans. I have a coolant temp sensor on top of the thermostat and it stays under 200 degrees all of the time so its like the thermostat isn't opening all of the way. But is also gets hottest on the highway.

Pull 1 degree timing :: 206F (97C)
Pull 2 degree timing :: 224F (107C)
Enter Open Loop Mode :: 228F (109C)

Pop the radiator cap and start the car, while its idling try burping the coolant system by squeezing the lower radiator hose (add coolant as necessary). Just watch your hands on the radiator fan and the exhaust parts, both can bite you if you aren't being careful.

From your symptoms (hotter coolant temps cruising and not at idle) it seems there could be just air in the lines, which is easier and cheaper to take care of than replacing a t-stat.

Thanks, I'll give that a try in the morning.

 

[BogusSVO]

How is your tune? If you run lean, you make more heat that will pass thu the head into the coolent jacket

 

[GRace]

Ok I squeezed the lower radiator hose and it didn't burp any air. I am staying out of open loop as much as possible since I cannot tune until I go WOT after break in. On the highway it is maintaining the 14.7:1 afr. Is it looking like I need to replace the thermostat?

 

[nickk90]

Isn't our stock thermostat 180? Around town my temps are 205-210

 

[gofer]

Ok I squeezed the lower radiator hose and it didn't burp any air.

While it was idling warmed up?

Sometimes those car shop t-stats are bad from the get go, this maybe one of those times you pitch the extra $10 and get the OEM replacement from Mitsu. I did it and haven't had to crack open the t-stat housing in years. What are you running for coolant in there, 50/50 mix?

 

[GRace]

While it was idling warmed up?

Sometimes those car shop t-stats are bad from the get go, this maybe one of those times you pitch the extra $10 and get the OEM replacement from Mitsu. I did it and haven't had to crack open the t-stat housing in years. What are you running for coolant in there, 50/50 mix?

I didn't do it while it was warmed up, do you mean after it has reached operating temp? I am running around 50/50 mix, I poured in about 2/3 gallon distilled water and the rest antifreeze.

 

[Abe'sGST]

I didn't do it while it was warmed up, do you mean after it has reached operating temp? I am running around 50/50 mix, I poured in about 2/3 gallon distilled water and the rest antifreeze.

yea that's when you have to do it, when its at operating temperature

 

[kthackst]

http://www.amazon.com/Lisle-24610-Spill-Free-Funnel/dp/B001A4EAV0

I use this everytime I add coolant.

1. put on car and fill up funnel 1/3 the way.
2. start car
3. keep car running with heater blowing until the radiator fans kick on twice.
4. CAREFULLY squeeze radiator hoses to get rid of all bubbles.
5. turn car off and let car cool completely down with funnel attached.
6. once car is cool remove funnel and excess coolant.

 

[TSiAWDRatlemstr]

Do you have a FMIC installed? Mine used to run 210-220 pretty much all the time and wanted to get hotter in the summer with a new radiator, OEM thermostat, Flex-a-Lite fans wired on all the time, etc. It was irritating. I made a shroud between the radiator and the intercooler and it dropped down to 200-206 all the time. No more overheating. I also have a stock '93 TSi with a water temp gauge and it seems to run 195-205 all the time, so I assume that that is the normal temp.

 

[Calan]

Anyone else find it odd that the OP is running cooler while idling around town than when he is out on the highway?

Just out of curiosity, when was the water pump and belt last replaced?

 

[phunny]

Anyone else find it odd that the OP is running cooler while idling around town than when he is out on the highway?

Just out of curiosity, when was the water pump and belt last replaced?

Yeah I was thinking it might be a HG but he didn't say he was pushing coolant.

 

[TSiAWDRatlemstr]

Mine did the same thing. It would overheat on the freeway and was fine in city driving. My front mount literally directed all airflow away from the radiator, under the car and would make it overheat. I was baffled almost all summer.

 

[GRace]

Anyone else find it odd that the OP is running cooler while idling around town than when he is out on the highway?

Just out of curiosity, when was the water pump and belt last replaced?

Almost everything on the motor is new. It is a fresh rebuild with 200 miles on it so far. New mitsu hg and arp studs. The only thing that isn't OEM is the water pump, it is a Gates which was made by GMB which is made in Japan and is an oem supplier for certain vehicles.

I don't want to try to squeeze the lower radiator hose when it is hot, I know I will burn the crap out of myself if it splatters out on my arm. In a couple days I am going to take the thermostat out and test it in boiling water. I personally don't think it is opening all the way. If it was air wouldn't it overheat all the time instead of consistently being at 210-215 degrees?

I don't have my fmic installed yet.

 

[gofer]

The reason why you need to burp it once its up to temp (180*) is so the t-stat is open and you remove the air thats trapped in the entire system. Even if you pull the t-stat and replace it/test it you still have to burp it with the engine at operating temp, why not try it now?

This is why you burp the coolant system with the engine warmed up, copied straight from the FSM. Its for the 2g so the info up top doesn't apply however, the fluid flow diagrams do.

You must be logged in to view this image or video.

 

[knochgoon24]

Just a FYI, the thermostat in DSMs are dumb. It has to do with the way the coolant flows past the thermostat. IIRC, the thermostat portion is on the cold side. The car ends up running almost 20*F hotter than what they're rated. I'd suggest getting a 170*F thermostat. I bet you'll run ~190-195 then.

 

[GRace]

Today I ran without a thermostat to see what the temps were. While driving around my house at around 25-30 mph the coolant temp would get between 195-206. If I got on the highway around 60 mph it would drop to around 190, but I didn't go more than a mile that fast. While idling, the fan kicks on and lowers the temps to 195 or so.

I tried to squeeze the lower hose and there wasn't air in the system. Any other ideas? I'm thinking about trying a 180 degree thermostat and seeing what happens.

 

[Calan]

I forget what the issue was. Those numbers sound perfectly normal, at least for a lot of 1G cars (including mine).

 

[GRace]

Do you mean normal for without a thermostat or normal with one? I'm not sure if maybe a thermostat will slow down flow and have any effect on the temps.

 

[sugarfree]

Only one person mentioned the possibility of the car running hotter due to having a fmic. Our cars did not come stock with one for a reason, any time you put something in front of the radiator it's going to make a difference.

 

[knochgoon24]

Only one person mentioned the possibility of the car running hotter due to having a fmic. Our cars did not come stock with one for a reason, any time you put something in front of the radiator it's going to make a difference.

But he's in Missouri. At this time of year, he shouldn't be having any overheating issues with a FMIC.

 

[clipto]

Another way you can try and cool temps if your not running a/c. Remove the a/c condensor, and get more air to the radiator see if that helps temps. Make sure your not running more water then coolant. You can go on ebay get a 1g cxracing aluminum radiator for like $80 they work nice.

 

[GRace]

So I just got done flushing my coolant system and installing a 180 degree thermostat. I am getting 205-210 degree idle temps but on the highway it goes down to 195 while cruising, and that wasn't for a very long drive.

Would that indicate that the radiator is not big enough? The one I have now is a 1 row aluminum radiator. I don't know if I just need a thicker one that holds more coolant. I am installing a fmic soon and need to get this figured out.