Question about 1999 Cadillac DeVille

1 Answer

Engine overheating in 1999 Cadillac Deville. Cooling fan not coming on but does kick in when A/C is on. This is my Mom's car and I need help

Posted by on

1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Expert
  • 192 Answers

The most common overheating problem with the Northstar engine is a blocked purge line(small hose).The purge line is designed to purge air out of the cooling system.
There is a small diameter hose coming from near the top of the coolant tank (not the cap) ,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.Or trace the hose back until you find the blockage.
The hose goes in to the engine to a crossover and comes out the other side close to the thermostat housing,the blockage may be there.

Also note that the cooling fans don't come on until the coolant temperature hits around 225 degrees.
During normal highway driving the fans will very rarely come on(if at all) due to constant air flow through the radiator.They will only usually come on in heavy traffic conditions on a hot day.
But......if you have the Air Con switched on, the fans will run all of the time.

Posted on Jun 02, 2010

×

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

1 Answer

Location of cooling fan sending unit 1999 cadillac deville?


If you are refering to the Engine Coolant Temperature (ECT) sensor,it is located on the right rear of the engine below the exhaust gas recirculation (EGR) valve.

HINT: If your Deville is equipped with the analog instrument cluster and the temperature gauge is working, or if you have the digital instrument cluster and the driver information center (DIC) has been diplaying messages telling you that the engine is hot, the problem with your engine cooling fans is NOT the sensor.

Jun 02, 2012 | Cars & Trucks

1 Answer

My 1996 cadillac deville overheats. i replaced the thermostat and water pump.. cooling fans do not turn on the only way to drive my car without it overheating is to turn on the a/c??? please help me


Hi Malik,
Thank you for choosing me to help you with your problem. In order to help you find out what to do with your Cadillac, I need to ask a few questions and get more information.
First, I need to ask you: When you turn the A/C on do BOTH cooling fans come on? If not, which one is coming on? The Left (driver's side) or the Right one?

Aug 09, 2011 | 1996 Cadillac DeVille

1 Answer

Cooling fans ok, radiator clean and clear, curious how low refrigerent could cause overheating engine?


cooling fans not working. No air coming thru vents. Don't even hear blower. 2001 Deville

Sep 16, 2010 | 2001 Cadillac DeVille

2 Answers

I have a 1999 Cadilac Deville that I replaced a


Are you sure the thermostat was in the wrong way ?.

The thermostat is located in the bottom hose unlike most conventional cooling systems.

The thermostat in the Northstar engine is a dual action device.
One end of the stem is the Thermostat(obviously) and at the other end is a spring loaded pressure valve(the thinner end).

Make sure the thermostat end is nearest the rubber hose and the pressure valve end is in towards the engine.

Also note that the cooling fans don't come on until the coolant temperature hits around 225 degrees.
During normal highway driving the fans will very rarely come on(if at all) due to constant air flow through the radiator.They will only usually come on in heavy traffic conditions on a hot day.
But......if you have the Air Con switched on, the fans will run all of the time.

For overheating problems consider the following......

The most common overheating problem with the Northstar engine is a blocked purge line(small hose).The purge line is designed to purge air out of the cooling system.
There is a small diameter hose coming from near the top of the coolant tank (not the cap) ,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.Or trace the hose back until you find the blockage.
The hose goes in to the engine to a crossover and comes out the other side close to the thermostat housing,the blockage may be there.

Jun 30, 2010 | 1999 Cadillac DeVille

3 Answers

1999 cadillac deville runs hot what are my options


The most common overheating problem with the Northstar engine is a blocked purge line. It's job is to purge air out of the cooling system.
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.Or trace the hose back until you find the blockage.The hose goes in to the engine to a crossover and comes out the other side to near the thermostat housing,the blockage may be there.
Also note that the cooling fans don't come on until the temp hits around 225 degrees.
During normal highway driving the fans will very rarely come on(if at all) due to constant air flow through the radiator.They will only usually come on in heavy traffic conditions on a hot day.
But......if you have the Air Con switched on, the fans will run all of the time.

Apr 11, 2010 | 1999 Cadillac DeVille

1 Answer

I have a 99 Cadillac Deville which is overheating and I think it is the thermostat. Can I do this myself? Is it easy to get at? I do have some mechanical skills.


you need to make sure the fans are turning on to cool the engine down first,the fans won't kick on until the coolant reaches 212 degrees ,make sure your not losing coolant ant radiator is full,check it when the engine is cold,the north star engines have a flaw in the head gaskets leaking,

Jan 04, 2010 | 1999 Cadillac DeVille

4 Answers

1996 Cadillac Deville- running hot


is the water pump, belt and tensioner OK? its not where you think it is. its on the drivers side of the front cylinder head.

Oct 03, 2009 | 1996 Cadillac DeVille

1 Answer

1999 Jeep Grand Cherokee Overheating and showing no oil pressure


the fan is controlled by a thermostat, if the vehicle has a/c it should come on when the a/c is on ,(engine running)

Aug 09, 2009 | 1999 Jeep Grand Cherokee

2 Answers

Cooling fan wont kick in


Could be the FAN MOTOR, COOLING FAN TURN ON SENSOR, even the PCM. There are 2 fuses . Also check fuse panel under hood in engine compartment

May 08, 2009 | 1995 Cadillac Seville

1 Answer

1999 cadillac deville overheats


every thing that is electric needs a power and a ground if running a new wire to the fans i would prefer you to use a inline fuse this will keep the wire from catching on fire. u could run the power wire to a fuse that is ignition switch 1,2,3 one of these will work so when u turn the key they kick on. also the ground could be a bolt on the bottom of vehicle. use a test light and see if that wire hanging down is a power wire. hope this helps

Mar 05, 2009 | 1999 Cadillac DeVille

Not finding what you are looking for?
1999 Cadillac DeVille Logo

1,449 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cadillac Experts

yadayada
yadayada

Level 3 Expert

75051 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22095 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

7726 Answers

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

Answer questions

Manuals & User Guides

Loading...