Question about 1996 Cadillac DeVille

2 Answers

1996 cadillac deville overheat..radiator?

Ive changed water pump, and thermostat, and it still will overheat.
The car can be showing 240 degrees and i feel the air blowing off of the radiator, and it is not that hot at all.

Ive flushed the radiator, and the water comes out of all slots. So it is not clogged, and i do not lose any coolant at all. I do not have any leaks.
Ive read alot about northstar engines and head gasket, but this car has very good power and runs great. Just that it overheats overtime.
It just seems the radiator is not removing the heat from the engine.

Posted by on

  • Anonymous Aug 20, 2009

    If the catalytic converter was stopped up or bad, wouldn't i not have as much power? The car has great power. If there is not any heat being pulled from the engine and the air is cold, wouldn't that be the radiator as it is used to remove heat? Every other car blows out hot air. Also the temp showed 190 degrees, i put my finger in the coolant and it was not that hot at all.



2 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Expert
  • 192 Answers

Check for coolant flow at the Purge line,this is a common problem on the Northstar.
There is a small diameter hose coming from near the top of the coolant tank,this is the purge line.
With the engine idling,pull the purge line from the tank,if there is no coolant flow from this small hose,it is blocked and this will cause overheating.If the hose is clear, check for blockage at the nipple on the tank.

Posted on Aug 22, 2009

  • Mark Carrington
    Mark Carrington Aug 22, 2009

    By the way, head gasket failure on the Northstar is very often misdiagnosed and is usually the result of a simple blockage as I've described.
    Also, air locks in the northstar are unlikely because it is self purging, this is what the purge line is for.


  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Master
  • 11,896 Answers

Check to make sure your exhaust or catalytic isn't clogged. Also thinner or synthetic oil will keep engine cooler. Are you filling up coolant system completely? Once it is filled the first time, you will have to burp the radiator hose and car should be running when filling. Let fill one full time, wait and burp hose, level will go down as fluid fills engine block, then you will need to refill system again. Check to see if you have a bleeding screw for your system as well

Posted on Aug 20, 2009

  • Nate Stansfield
    Nate Stansfield Aug 21, 2009

    I would test the temp gauge to make sure it is not faulty, if you are not getting hot air either, then you may have a faulty heater core.



Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Why does my Grand Cherokee overheat after replacing the radiator?

there are many causes of overheating.

first off is you didnt stated engine option (size)

the engine can make excessive heat too. (late timing)

1: bad thermostat. 190 is ok, but it can be bad, even a new one.

try a quality brand like STANT, not dura . etc.

2: it must hold pressure, bad cap>? 12-15 psi

3: gee, did use 50% AF. it will not run right with out AF antifreeze.

4: bad water pump. running old AF causes the impeller to rust to nothing.

5: thermostat up side down, or bleed hole not up hill (jiggle pin,etc)

6: pressure in the hose , does NOT prove flow. only pressure.

7: air flow to RAD bocked, (at A/C condensor or between)

8: bad fan and related parts, varies by engine option not stated.

9: bad fan controls. same.

10: seem like it overheats even PARKED. right? never moved.

11: if it dont overheat moving fast this is a BIG clue. but nobody wants to take that risk of 10 is true. sure.

12: air in block, did you , ignore the side tank and look in side rad for full of AF 100% by pulling cap cold, over and over, each cold cycle

until dead sure its FULL???????

13: BAD TEMP GUAGE, DID YOU USE AN IR PYYO GUN to prove the thing is really overheating

14: is it boiling over, that is steam or hot water blasting to the expansion side tank???? signs/ got real signs of overheating?

15: passes rad leak down test?

16: passes exhaust leak test to rad test? green/blue checked?

17: steam out tail pipe end hot?

18: pinging, (too hot sighs)

19: OBD2 scan tool shows, 240 and the dash gauge and the pyro gun

all agree its 240"

20: sludge packup on sides of water jackets, seen when pump was pulled and NOT CORRECTED (flushed>?)

at the least.

ok one more , fan belts slip?

Apr 30, 2014 | 2000 Jeep Grand Cherokee

1 Answer

Monte carlo blows cold air and overheats

It really runs hot within a minute of starting ?
An engine that runs hot in a few minutes is often having problems with the water pump or a blockage in the cooling system. The thermostat does not open until 195 degrees which takes 5 or 10 miles of driving.
During that time, the water pump should be circulating coolant in the block and the heater hoses.
A leaking head gasket should be putting extra pressure into the cooling system, and-or dumping coolant into the cylinders which would come out the exhaust pipe. But it should still take a few minutes for the engine to reach the boiling point of 240 degrees.

Mar 09, 2014 | 2004 Chevrolet Monte Carlo

2 Answers

2000 chevy impala overheats i think its something electric

I doubt its anything electric.
Are you sure the radiator is full of coolant ?
Do both radiator hoses get hot when the thermostat opens at 195 degrees ?
Do both heater hoses get hot after running the engine for 5 min ?

Feb 06, 2013 | 2000 Chevrolet Impala

1 Answer

My 740 1998 BMW overheats? I have replaced 3 blown out radiators, 2 thermostats, radiator sensor, changed coolant, and radiators cap. What could it be the problem?

3 blown out radiators....define this. My accord has 224,000 miles on it, same radiator, same clutch. And the beemer blows radiators? Makes 'em explode? Can't imagine anyone making a radiator that blows up all the time. You keep buying the same model?

Anyway, check: air gap in system, bleed the system while it heats up. Water pump. don't see it being replaced. the older ones had plastic impellers. is the auxillary fan working? It should come on all the time when the A/C is on. Clutch on belt driven fan ok? put in a 12 degree cooler thermostat and drill two 3/16" holes 180 degrees opposite each other.

Blown head gasket or two can cause overheating. Bad timing. did you change a good or bad radiator sensor? how'd you test it to determine it was bad? Don't just replace parts, determine they're bad. Replace enough parts and $14,000 later you should be ok.

Jul 17, 2010 | 1998 BMW 7 Series

2 Answers

95 Jeep Wrangler YJ...No heat, temp at about

It should be 200 degrees. If your running cold the only thing that regulates temp is the thermostat. If it is indeed 150 degrees thats why you have no heat.

If you replaced the water pump and the radiator for this condition then it was a waste of money. If you had a water pump or radiator problem it would overheat.

The fact that your blowing cold air tells me the that you really are 150 degrees or the heater core is plugged.

Mar 10, 2010 | 1995 Jeep Wrangler

3 Answers

It is overheating in 32 degree weather.....I have checked to see if my radiator is gettign enough anti freeze and it's fine but i dont know why it keeps overheating

The engine overheat is due to inefficient cooling. Therefore, there is coolant in the radiator but if it doesn't circulate inside the engine water-jacket to remove the heat generated from combustion's chambers, then it still causes overheat. If this keeps happening then it can cause the engine head wrapped then leaking from the gasket as people called blowed head gasket. It could be: 1- Thermostat is not opened. 2- Water pump is not working. Before starting to replace parts, it needs to verify it it is the root cause of the problem. Take out the thermostat and run the engine to feel if there is water flowing inside the upper hose. A- If it is not then water pump is not working. B- If is, then run the car a few days without thermostat to see if it causes overheated. C- Running car without thermostat still causes overheat then there are some clogging up in the water jacket defeating the cooling efficiency--> Need a good flush. Good luck.

Dec 02, 2009 | 2003 Oldsmobile Alero

2 Answers

Overheating Express

is it acually getting hot or is it just the gauge on the dash saying so? a quality scan tool can show you what the coolant temp sensor is telling the pcm it may differ from the gauge.

Jun 17, 2009 | 2005 Chevrolet Express

3 Answers

I have a 97 bmw 316i, we have changed the water pump, checked heads and changed radiator, bleed it at a 40degree angle filled it with coolant and it is still overheating after a ten minute drive?

You actually need the thermostat in to pressurize your cooling system or the coolant won't cyle through the radiator, it'll just cycle around the engine. Most people think without the thermostat in the coolant will just pump freely through the engine and radiator, but it doesn't.

Chuck in a new thermostat, purge the air out of the system and see if it overheats then. I gaurentee it won't, if it does then you've got head problems (but they should already be obvious by now).

Jul 21, 2008 | 1996 BMW 318

Not finding what you are looking for?
1996 Cadillac DeVille Logo

1,780 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cadillac Experts


Level 3 Expert

85223 Answers

Jonah Oneal

Level 3 Expert

14092 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22485 Answers

Are you a Cadillac Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides