Hey There,
I am replacing the upper and lower intake gaskets on my 2003 Buick Park Ave. 3800v6 and wanted to know if I should put thread locker on the bolts. It looks like some go into a water jacket so gasket sealer maybe? I do have a FSM but you guys are faster!
Thanks.
Valve cover gaskets also, throttle body too.

You want thread sealant on the lower manifold bolts.

As said the LIM you want to use a Teflon sealer and not the locktite. Don't use it on any of the bolts.

thanks guys, putting it together tomorrow, hope all goes well.

Would the thread sealant advice apply to a 2000 buick lesabre as well? My husband and I just replaced the head gaskets and rebuilt it again from the head gaskets on up but we're still having trouble... Could a lack of thread sealant on the lower intake manifold bolts be the problem?

What would that be?

Still getting misfires in cylinder 5 like we were before replacing gaskets and rebuilding. Also, it doesn't want to start if it'* been running and turned off recently.
I made another post yesterday detailing all the problems we've had with this thing but it hasn't been put up/approved yet. If/when it is, I'll link it here.

Both are the same engine from this perspective. The other thread is available over at: https://www.gmforum.com/buick-172/20...cement-313500/

I put some time into a reply a few minutes ago.

Here'* what'* been going on with my car. Wondering if not having put the teflon thread sealer on the bolts of the lower intake manifold might be the issue.

https://www.gmforum.com/buick-172/20...cement-313500/

Got everything back together but have one problem. the main reason I did this was because it was leaking coolant out of the elbow that goes into the intake. it'* the metal elbow.
In trying to get it put back together I noticed the seal wasn't very good on that O ring. kinda wiggled. I pulled the belt tensioner off and looked at it. the hole is clean and smooth. tried different O rings to no avail. bigger ones wouldn't fit. I haven't put coolant in it yet. should I put thread sealer or gasket sealer around the O ring?
Ooooh! how about the good ole J-B Weld! LOL. Actually, that might be the best thing.
thanks guys.