Repair Guide: 3.9L T-stat change (3.5l similar)
#1
3.9L T-stat change (3.5l similar)
Swapped my t-stat not that long ago and took some pictures. My little manual says that the 3.9 and 3.5 should be similar, but that the V8 needs the exhaust manifold removed. I don't know about the V8 as I haven't worked on one.
Step one:
Drain the coolant, engine holds 3 gallons so make sure you have something that can hold that much if it all comes out.
The drain plug from above, I reached down with a pair of needle nose pliers to break it loose then turned by hand.
The coolant will drain from this little opening in the air dam underneath the passenger side.
Step two:
Disconnect the lower radiator hose from the t-stat housing. Some coolant may come out depending on how much is still in the block.
Step three:
Remove the t-stat housing. Two bolts, the upper will require a deep socket or wrench if you can get it on there. I think they were 8 or 9mm bolts (anyone confirm/deny?).
With the t-stat housing off the t-stat itself should just pull on out. If it's stuck try bumping it a little, I just tapped mine with a wrench.
I would like to add that when you are putting the new t-stat in that you need to carefully push the new t-stat into the housing, and make sure it seats correctly before you install the t-stat/ housing. (MAMONTE)
Installation is the reverse, don't forget to screw the drain plug back in!
Pictures of the inner gasket that went wrong with mine.
^That's the t-stat still stuck in the housing.
Step one:
Drain the coolant, engine holds 3 gallons so make sure you have something that can hold that much if it all comes out.
The drain plug from above, I reached down with a pair of needle nose pliers to break it loose then turned by hand.
The coolant will drain from this little opening in the air dam underneath the passenger side.
Step two:
Disconnect the lower radiator hose from the t-stat housing. Some coolant may come out depending on how much is still in the block.
Step three:
Remove the t-stat housing. Two bolts, the upper will require a deep socket or wrench if you can get it on there. I think they were 8 or 9mm bolts (anyone confirm/deny?).
With the t-stat housing off the t-stat itself should just pull on out. If it's stuck try bumping it a little, I just tapped mine with a wrench.
I would like to add that when you are putting the new t-stat in that you need to carefully push the new t-stat into the housing, and make sure it seats correctly before you install the t-stat/ housing. (MAMONTE)
Installation is the reverse, don't forget to screw the drain plug back in!
Pictures of the inner gasket that went wrong with mine.
^That's the t-stat still stuck in the housing.
Last edited by God_Bot; 02-18-2010 at 09:45 AM.
#2
mine was disentergrated i had the shop do mine do to a bad experence when one stuck open and it ended up pluging up the new t-stat. the shop took off the one head to try to fish it out they didnt charge me for it do to it was a dealer and they said it was a manufactures defect and they wanted me to be pleased to know they got all of the peaces out of the engine. i wanted to ask them if they could do a port and polish while they had every thing apart getting the rest of the thermistat out of the heads. well thats my good experence the bad is it was stuck shut and my brother drove my 3.8 comaro 5 miles down the high way i was ticked
#7
Yea, I paid $49.95 for my t-stat at the Chevy Dealer.
The 3.5L is identical to the 3.9L for the t-stat replacement. My original t-stat had the same innner gasket problem.
I would like to add that when you are putting the new t-stat in that you need to carefully push the new t-stat into the housing, and make sure it seats correctly before you install the t-stat/ housing.
The 3.5L is identical to the 3.9L for the t-stat replacement. My original t-stat had the same innner gasket problem.
I would like to add that when you are putting the new t-stat in that you need to carefully push the new t-stat into the housing, and make sure it seats correctly before you install the t-stat/ housing.
Thread
Thread Starter
Forum
Replies
Last Post
John Cn'tgetRite Veal
Monte Carlo Repair Help
4
03-09-2013 07:54 AM
Montelicious
PRIVATE Wanted Classifieds
18
07-06-2010 02:44 PM
Cowboy6622
General Monte Carlo Talk
27
12-03-2007 01:02 PM