Engine running hot

Tiny
MARKVELLUTATO
  • MEMBER
  • 1999 CADILLAC DEVILLE
  • V8
  • FWD
  • AUTOMATIC
  • 122,000 MILES
Digital coolant temperature reading on the dash perfect at about 190 degrees. If I sit at a long red light or just creep along in a traffic jam, the coolant temperature will go as high as 220-224 degrees. Is this normal? How high can the coolant temperature get before I need to worry about blowing a head gasket?
Wednesday, May 4th, 2011 AT 3:02 AM

49 Replies

Tiny
FACTORYJACK
  • MECHANIC
  • 4,159 POSTS
As long as there is no message of engine overheat. The characteristic of a Northstar is not necessarily a head gasket blowing, but much more a condition of the threads in the block failing causing lost clamping force and internal leakage. Make sure your cooling fans are coming on, at a minimum when the A/C is requested, and also at the higher coolant temperatures.

I would change the engine coolant temperature sensor it could be getting out of range so the cooling fans can come on easier. This guide will give you an idea on how to do it.

https://www.2carpros.com/articles/coolant-temperature-sensor-cts-replacement

Here is a guide that can help

https://www.2carpros.com/articles/engine-overheating-or-running-hot

Please let us know what happens.

Cheers
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Wednesday, May 4th, 2011 AT 4:26 AM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
That would be completely normal. The electric cooling fans are not programmed to come on until around 226 degrees. As long as the temperature responds to the fans, you are fine.
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Wednesday, May 4th, 2011 AT 1:00 PM
Tiny
CADIEMAN
  • MECHANIC
  • 3,544 POSTS
You need to watch the temperature on the dash. It will go to 220's then you will see it start going down when the fans come on. When the temperature is low enough they will turn off. When you see the temperature go back to 220's they will turn back on. The heater core could be leaking. The A/C case has a drain it has a rubber hose coming out of the A/C case. It is right below the evaporator. Check it for coolant leaking.
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Wednesday, May 4th, 2011 AT 4:45 PM
Tiny
DEONELOGAN
  • MEMBER
  • 1 POST
  • 1997 CADILLAC DEVILLE
My 1997 Cadillac DeVille was running hot spent lots of money need to take the 1/4" line from the reservoir tank to drivers side of the engine blow line and the engine mine was plugged solved my heating problem
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
JAMES W.
  • MECHANIC
  • 2,394 POSTS
Sounds like your cooling fans aren't working. Going down the road you will get enough air being forced through the radiator to keep the engine cool, but at low speeds or at idle, you need the fans. Most common failure is the engine temp sensor located on the thermostat housing. Or, it may be a control relay on the fan housing itself. Hope this helps.
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
JESSBUG2009
  • MEMBER
  • 2 POSTS
  • 1994 CADILLAC DEVILLE
  • 150,000 MILES
I just bought this car and I have to put water in it anytime I go somewhere or it runs hot, what could cause this? Also IO33, IO34, IO37, IO39 show up on the code inspection thing. How can I fix this and about how much is this all going to cost me?
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
If coolant is depleting all the time, you have a leak somewhere or it could be worse, a bad head gasket.

Try clearing the IPC codes and see if they come back.
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
CADIEMAN
  • MECHANIC
  • 3,544 POSTS
Jess u need to have your coolant sys. Pressure tested checked NOW.
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
JESSBUG2009
  • MEMBER
  • 2 POSTS
Well I had the water pump, radiator hose, and a new timing cover gasket set put on it. But it still leaks the water out. The water comes out before the car is even turned on.
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Did you check where the leak is coming from before replacing those components?

That is a bad leak and you should be able to locate its source easily.
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
MACHINIST1!
  • MEMBER
  • 3 POSTS
  • 2000 CADILLAC DEVILLE
  • V8
  • AUTOMATIC
  • 109,000 MILES
I have a 2000 Cadillac deville having a problem with the car running hot sometimes the gauge will reach all the way to the top but car never steamed or has white smoke coming from under the hood. I pull over let the car cool I check antifreeze usually takes anywhere from a quarter of a bottle to a half of a bottle and I'm using dex-cool (I have noticed that when the car is cooling before I put the antifreeze in it it does sound like water is boiling under the hood.)After I put antifreeze in the car it seems to run fine for about a week then it starts to run a little hot again I have noticed a little bit of an oil leak underneath the car not sure that has anything to do with this but I want to figure out what is making this car run hot I have checked all the fluids none of the fluids are mixing with one another. I go through a bottle of antifreeze in about 2 weeks. Do you think it could be a fan problem or do you think it could be a thermostat or radiator problem or maybe even a water pump issue? How much will it cost to fix?
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
CADIEMAN
  • MECHANIC
  • 3,544 POSTS
Fill it full and youll see it. Gl
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
JOHNNYT73
  • MECHANIC
  • 924 POSTS
You to have to have the system pressure tested to see where the leak is coming from. You could start the cheap route and try replacing your cap to be sure it is working properly.
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
MACHINIST1!
  • MEMBER
  • 3 POSTS
I had a new overflow reservoir put in along with a new pressure cap.
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
JOHNNYT73
  • MECHANIC
  • 924 POSTS
Ok, are you sure you burped all the air out of the system?
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
MACHINIST1!
  • MEMBER
  • 3 POSTS
How can I get or br sure the sir is out of the system?
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
BLUEJEAN
  • MEMBER
  • 20 POSTS
  • 1998 CADILLAC DEVILLE
  • V8
  • FWD
  • AUTOMATIC
  • 130,000 MILES
Engine Cooling problem
1998 Cadillac Deville V8 Front Wheel Drive Automatic 130,000 miles

I replaced a water pump and a thermostat on a 1998 cadillac deville with the northstar engine. It starts to run hot at times. I was wondering is there a bleeder screw to get the air out? Please let me know. Thank You.
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
BUZZSAW
  • MECHANIC
  • 1,198 POSTS
Is it running low on coolant still, dont keep running it hot you will do damage if its not already done. Have it pressure tested for leaks and get back to me
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
BLUEJEAN
  • MEMBER
  • 20 POSTS
I'm loseing coolant but the ground is dry and the oil is clean.
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)
Tiny
MICHELLE COBB SMITH
  • MEMBER
  • 2 POSTS
  • 2000 CADILLAC DEVILLE
  • 4.6L
  • V8
  • AUTOMATIC
  • 138,000 MILES
Started running hot so we had to stick the thermostat open because you cant take it out in this car. It did good for a while then started getting hot again. Please help me.
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Saturday, December 2nd, 2017 AT 2:54 PM (Merged)

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