IM bolts

jaguarjoe

Original poster
Member
Nov 22, 2012
73
I searched and searched, nothing jumped out at me.
In the nutshell, what's the scoop with intake manifold bolts? Months ago, I read about them either here or in the dark side forum, but because they weren't an issue for me, I didn't give it a lot of thought. Now, they might be an issue.
Can someone please get me pointed in the right direction?

Once again,
Thank you very much!
 

Robbabob

Member
Dec 10, 2012
1,096
jaguarjoe said:
I searched and searched, nothing jumped out at me.

I searched using Roadies suggested tool within Google: "intake manifold bolt site:gmtnation.com"

Rather than give you the final answer on the bolt, I'll let credit go where it's due in the thread, find your answer here.

Good luck!

edit: grammar/spelling mistakes drive me crazy! ~I'm not ocd, I'm OCD!~
 

MAY03LT

Member
Nov 18, 2011
3,431
Delmarva
The bolts can slightly loosen up over time which can allow unmetered air past the intake gaskets and into the engine. The truck can set a P0171 code. From what I've seen, it only happens when the engine is cold, like if the truck sat overnight. Once the truck warms up, fuel trims are normal as if nothing were wrong. I suspect that the gaskets expand a little when they warm up, then the leak disappears.

I recall a few folks checking theirs when this first started being reported, and a good bit of those people said that theirs were in fact loose.
 

AbsoluteZero

Member
Nov 21, 2011
211
What all has to come off if one wanted to check if they were tight? I had the pcm off several months ago and I think I could see a couple of them but didn't actually check if I could get socket on them.
 

jaguarjoe

Original poster
Member
Nov 22, 2012
73
I shoulda been more specific with my first post. When she drives the TB, at some throttle positions, the TB makes a moaning sound, almost like a fog horn but not nearly as loud. I thought that there could be something common between the moan and the bolts. Apparently I was wrong.

If its nice tomorrow, I'll try and check the IM bolts.

Thanks!
 

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