: 2002 Deville Overheating after Thermostat replacement



JohnV
06-19-14, 07:36 PM
Replace thermostat about a month ago and all worked fine, but now it is overheating again. Any thoughts?
Help would be appreciated. Thanks, John

2manyhotrods
06-19-14, 07:45 PM
Air pocket maybe?
They are a brute to bleed air out of.

MoistCabbage
06-19-14, 10:36 PM
Not if the purge line is clear, then they are. Instantly self bleeding. Zero effort required.

John, :welcome:

How hot is it getting when it's "overheating"? Under what conditions is it overheating? Idle? Cruise? When accelerating?

04GrandAmGT
06-20-14, 09:32 AM
check purge line if that is free flowing, get a block test done, sounds like early signs of HG.

JohnV
06-20-14, 12:36 PM
One to two lines up on gage while cruising. Will come down to normal if left a idle for a short while, maybe 15 minutes or so.

04GrandAmGT
06-20-14, 12:58 PM
sounds like you might be lucky and just have a clogged purge line. theres a hollow bolt that the purge line clamps to thats normally the point where it gets clogged

arctic_man
06-20-14, 04:10 PM
sounds like you might be lucky and just have a clogged purge line. theres a hollow bolt that the purge line clamps to thats normally the point where it gets clogged

To check the purge line: Start the car, remove the rad cap, and then remove the purge mine where it connects to the coolant tank. Coolant should be flowing from the line you disconnected. If not, it is clogged somewhere. Per Everett, the hollow bolt the purge line connects to is typically the culprit. Take some compressed air and flow it out. It should start flowing again. If that does not work, you can take the appropriate sized drill bit, and carefully drill the hole out to clear the crap.

maeng9981
06-21-14, 07:24 AM
Did you put the air bleed hole on the thermostat pointing at 12'o clock position?