Question about 2004 Pontiac Grand Prix
Thanks for answers but let me clarify: I have replaced the heads, head gaskets, thermostat, engine oil and the radiator is less than 6 mos. old. It had blown a head gasket, and cracked heads were discovered so I replaced everything. Sad, I know. Now the engine temp is stable except under these two conditions: 1: When coming off a freeway drive and coming to idle at a stop light the temp will spike after a few and then go back down in a few minutes. 2. When driving on the freeway and then slowing down in traffic the temp will rise and then go down gradually. Strangely, turning on the AC seems to quicken the cool down. So, the entire coolant system has been replaced. What now?
Replace your coolant temperature switch,it's screwed into block by oil filter.Here's a picture of what it look's like.Your water pump working properly.Are your spark plugs burning clean,not oily from bad piston rings?
Posted on Jan 16, 2013
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
The only next logical step is to have the radiator flushed and cleaned. Over time the radiator slowly builds up deposits along the fins and reduces water flow and heat dissapation. Sometimes Iv'e seen radiators get so full of deposits that only half the radiator is actually working. I have also seen this motor in other GM applications have computer problems and the cooling fans won't run when they should, but when this happens you start to see other funny stuff happening that gets hard to explain till a bad cumputer gets diagnosed. I assume everything else on the engine and car is working fine and your not noticing any other strange behavior from the engine, like hard to start sometimes and other times it starts fine, air conditioning fans work and then they quite and then work again for no apperent reason. If these type things are happening you might want to make sure your computer is working fine, and all the relays are working. Also make sure you do not have any abstructions in front of the radiator blocking air flow. there is also a sensor on top of the plennum that tells the fans to kick on, check this also.
Posted on Nov 17, 2010
Tips for a great answer:
Sep 09, 2015 | Pontiac Cars & Trucks
Feb 04, 2013 | 2004 Pontiac Grand Prix
Sep 05, 2012 | 2000 Pontiac Grand Prix
Aug 03, 2012 | 2004 Pontiac Grand Prix
For thermostat replacement step by step instructions with pics-
The pics as shown are for a GP model, but the GTP shares the same block so the thermostat is in the same place.
Your model year may require a gasket instead of an optional "o" ring. Buy one before you start and when you pull it apart, see if it has a gasket. -If so replace it, if not return the unused part.
Hope this helps. "G"
May 24, 2012 | 2004 Pontiac Grand Prix
Jul 01, 2011 | 2004 Pontiac Grand Prix
Apr 12, 2011 | 2000 Pontiac Grand Prix
Feb 08, 2011 | 2004 Pontiac Grand Prix
Apr 17, 2010 | 1997 Pontiac Grand Prix
Aug 28, 2009 | 2002 Pontiac Grand Am
194 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: