97 LT1 engine heat issue

Hi guys, I have a 1997 with an LT1 in it. The engine seems to hover around 180 degrees at cruising speed. If I have to slow down to 20-30 mph or I stop for a red light, the engine temp go's over 210.

I got home the other day and the engine temp was almost 210 so I let it sit in the driveway for a few minutes in park and it reached halfway between 210 and the next hash mark. Then, with the car still in park, I gave it some gas and the engine temp shot back down to 180 when I got just over 2,000 rpm.

Any ideas guys? I am fairly new to working on my car. Thanks for looking at this.

Dave

Hi guys, I have a 1997 with an LT1 in it. The engine seems to hover around 180 degrees at cruising speed. If I have to slow down to 20-30 mph or I stop for a red light, the engine temp go's over 210.

I got home the other day and the engine temp was almost 210 so I let it sit in the driveway for a few minutes in park and it reached halfway between 210 and the next hash mark. Then, with the car still in park, I gave it some gas and the engine temp shot back down to 180 when I got just over 2,000 rpm.

Any ideas guys? I am fairly new to working on my car. Thanks for looking at this.

Dave
These are normal operating temperatures. Also keep in mind that the stock temp gauge isn't the most accurate. If you are worried about engine temp then you should buy an aftermarket gauge and sending unit. There are ways to make it run cooler as well, such as a lower temp thermostat, lower temp fan switch, water wetter...etc.

The reason it cooled down when you gave it some gas while idling, that sped the engine up thus speeding up the water pump which pumped the hot water out and the cooler water in.

I understand that the engine will change in temp at times but, on my way home today I got stuck at a long red light and the temp Gage went into the red causing the check gages light to come on. I have owned the car for 5 years and that is not normal.

I am not trying to dispute or argue with anyone, I just know there is a problem with the car.

Make sure it is full of coolant and the cooling fans are coming on. also check that the radiator fins aren't full of dirt or bugs that would restrict airflow, try washing it out good with a hose. Sitting in traffic mine will get above 210 pretty quickly but you are right it shouldn't go into the red.

I have checked the coolant a few times, it is full every time.

How do I check that the fans are working properly? I thought that might be the problem but the shroud keeps me from doing a visual inspection while the motor is running.

I'll look at the fins again and clean it if needed.

ok, now that you say that it went into the red I know you definitely have a problem. My 91 would heat up to 220 before the fan kicked on, which is why I said your temps are normal.

Anyway, it sounds like your fan isn't coming on. How do you check? Drive the car around until it heats all the way up, pull back in your driveway, leave it run, pop the hood and wait. while watching the temperature gauge. the fan should kick on before it goes into the red. You will be able to hear it.

What is the mix ratio on your coolant and age? Also, mixing dexcool and stnadard anti-freeze can cause a sluge type substance to develop and clog things up a bit. :2cents:

What is the mix ratio on your coolant and age? Also, mixing dexcool and stnadard anti-freeze can cause a sluge type substance to develop and clog things up a bit. :2cents:


With stuff going on this weekend I was not able to test the fans yet.

50/50 mix put in by the local shop about a month ago.

50/50 mix put in by the local shop about a month ago.

Routine Maintanence or something else? Could also be a air pocket in the system.

I blew a radioator hose open so I had to get a new hose and a fill.

A few days after the shop filled it, my car meet a deer. No damage to the engine, just body panels. On the way home from the estimate, it started over heating. I went home and looked to at the coolant levels, they were normal. I bled the system for air, just in case, and it has not improved. I have a buddy who has a mid 90's caprice with an LT1 and he has been helping me look the system over. I replaced the fan relays, all three of them, and it did not help. I want to get the front end up to look at my water pump, but people keep telling me that if my weep hole was leaking, I would be loosing coolant. I don't have the money to take it to a shop.

A few days after the shop filled it, my car meet a deer. No damage to the engine, just body panels. .

AH!, front end? Did you lose the air dam?

I don't think its a air dam cause it does it while its sitting and the air dam serves no purpose while the car isn't in motion. I think either you still have air in the system or one of your fans called it quits but I highly doubt its water pump related cause who ever told you it would leak out of the weep is correct.

I don't think its a air dam cause it does it while its sitting and the air dam serves no purpose while the car isn't in motion. .

I know I've been out of the loop for a bit here, BUT, the air dam is the only thing that directs air up to the radiator at all times. :dunno: :screwy:

I would chek the thermostat some times it gets stuck and you have to put presure on him so he will open

I was under the car today, air dam is intact and the weep hole is dry. I have a guy that is going to test my fans for me tomorrow.

How would I go about testing the thermostat?

Also, while under the car I noticed what looked like caked up oil on a electrical connector right behind the lowest pulley on the car. Is that normal?

Well, testing got done today. The fans do work, they kick on at 220 degrees and turn off at 200 degrees. Does this sound like it is in spec?

From what I was told, the water pump looks good also, so it leaves me with a bad heater core and/or radiator clog. It was not until the heater core got brought up that I remembered a small puddle on the passenger side floor board about two weeks ago. It was after a rain storm and has not been back since so I thought it might have been a bad seal on the door.

Does this sound like the right path I should be on?

could very well be. Any leak in the coolant system would let in air and let out coolant which would raise temps and create hot spots.

Could that also trigger the low coolant light?

Thanks for the help guys, I had a new heater core installed yesterday and the car is back to running around 180 degrees. The guy told me the core was nasty.