Manifold Bolts On 1999 newer Silverado

[Profire73]

I am new to the forum but I know that this is where you usually get the best results.

 

By buddy and I both own 1999 silverado's with the 6.0L. Last summer I had to have 5 manifold bolts replaced due to they where all busted off. Now he called me and has the same problem, he has 6 of them broke.

 

We called the dealership to complain, figuring there was some type of recall and they only thing they found out was that there was a recall on the bolts but not a GM recall. Didn't make sense to me but O.K.

 

Anyone else have this problem and if so did GM do anything about it?????

 

Just so everyone knows, I have stock manifolds and have never touched them.

 

Thanks for any help.

 

Mike

[SteveCZ]

I thought 99 was the first year for the NBS trucks.

 

They only offered them in 1500 series, which had the following engine choices:

 

4.3 V6

4.8 V8

5.3 V8

 

The 6.0 was offered in the 2500 and up, which came out the following year, or was it 2001? Either way, I'm 99.999% sure you couldn't get the 6.0 in the 1500.

 

But that aside, how did you know that you had to have them replaced? Did you hear any noises like a loose heat shield, or ????

 

I've been thinking about checking mine during my next oil change to just make sure they were tight, but I always get frustrated when I try to get that one grease fitting I can never get to.....

[marman]

The 2500 Silverado came with the 6.0. See my sig.

[Profire73]

Sorry about the confusion. I have a 1999 2500 w/the 6.0L. First year of the new body style.

 

The reason I knew mine needed replaced is because I had that horable ticking sound like it was an exhaust leak and I let it go for about a week and then it was driving me crazy.

 

When started looking for the leak, I noticed that some blots were broke and the more I looked the more I found.

 

When I took it to the dealership they said that it was not common and they never saw one with maniflod bolts busted on the 1999 newer body style.

 

SO that is the morale of the story.

 

Thank God for Extended Warrenty!!!

[SteveCZ]

Sorry about that guys... just went on Kelly Blue Book and saw that they made the 2500's in 99 too...

 

Don't see too many of them around up here in NY, most of the 2500's are HD's up here, and you can tell those apart pretty easy

[AZ-Z71]

Yeah, my 1500 '99 NBS had the first one on the drivers side break. When you show it to people the first thing they ask you is what did you try to retorque it. The answer is no I found it that way. Honest truth. Mine was broken flush with the head and had to get the head drilled to get the bolt out, which meant pulling the head out of the truck. After $800 and a few months later I'm now hearing a tick which sounds like the exhaust manifold is leaking. This time all the bolts are there.

 

Tick starts usually when the engine drops below operating temp and last until the temps comes back up. This is not the same as the CSK tick which I also have which is more of a ten second tick then gone. I could live with that one. This new tick is driving me crazy.

[Tahoe933]

I don't think this is a new problem. My '95 did this as well last year. I believe that the problem is in the machined tolerances for the bolt holes in the manifolds compared to the tolerance of the holes in the heads. The 4 outer bolts on my DS manifold were binding on the manifold when I tried to reinstall after fixing the broken bolt. That misalignment will only get worse as the motor heats up. After a bunch of repetitive side loads, those bolts will fatigue and break.

To try to insure it doesn't happen again, I opened up the manifold bolt holes a bit to get side clearance back.