I know this is an Impala forum, but This is a 92 Buick Roadmaster with the SBC 350 TBI 5.7, ive noticed that they are almost sister cars badged under different names so that's why i decided to post here, but hopefully you can still help me.

2 years ago I replaced the intake manifold and 1 year and 1/2 down the road the rear china wall blew out. I had used High Temp red RTV all around, and red rtv on the bolt threads to seal them. Torqued it in sequence to 35 ft lbs, but never re-torqued it. (Rented torque wrench from autozone)


So next time around I used Permatex "The Right Stuff" on rear china walls, and Ultra black rtv around coolant ports both side of gasket, and some Permatex High temp thread sealant on the bolt threads. Torqued it in sequence to 35 ft lbs, but never re-torqued it. (Rented torque wrench from autozone again)

Both times it sat well over 24 hours before start up

Well now 6 months down the road I noticed a Very very small amount of coolant trying to ooze it's way under the ultra black rtv around both front coolant ports. So took a 14mm wrench and tightened them. They did turn a bit.

My question is. Could I have messed anything up by doing this? or Did I do anything wrong?

Thanks for anyhelp

 

Any help please? Just need to know if it's alright what I did.

 

Based purely on years of mechanical work and some experience on the GM 350ci small block I would suggest re-torquing the manifold bolts, on a cold engine, in the proper sequence after 100 miles of use and again after 300 miles of driving. It can't hurt and it may prevent the problem you are having. Don't simply tighten two or three bolts where the leak is. This may warp the manifold and in most cases this is permanent damage that requires machining the mating surfaces back to true. Good luck.