Question about 1999 Cadillac DeVille
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
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.
Posted on Jan 02, 2017
Tips for a great answer:
Jun 02, 2012 | Cars & Trucks
Aug 09, 2011 | 1996 Cadillac DeVille
Sep 16, 2010 | 2001 Cadillac DeVille
Jun 30, 2010 | 1999 Cadillac DeVille
Apr 11, 2010 | 1999 Cadillac DeVille
Jan 04, 2010 | 1999 Cadillac DeVille
Aug 09, 2009 | 1999 Jeep Grand Cherokee
Mar 05, 2009 | 1999 Cadillac DeVille
1,496 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: