Oh My !***!

DSN46 · October 7, 2008

Howdy,

So I had an exhaust "knock" going on when the engine was cold. Once warm, it stopped.

Did I just say "who cares... leave it alone"... NO sir! O'l James just had to dig into it and find that my driver's side manifold was missing the rear-most bolt! Yep, broke off. Causing a small leak back there by the firewall. I could have just not looked and went on my merry way.

Now... my mechanic is taking apart my engine to remove the head so he can drill out the broken bolt.

He isn't screwing me or anything.. he gave an honest shot at getting at it with the head in place on the motor...just not enough room back there.

This little damned gem is going to run me $800.00.

What the hell was GM thinking when they made these bolts? How do you justify making a bolt that pops the head off while sitting there?

I just had to rant. I know others have felt my pain, and believe me I'm sorry you had to go through it also.

Can anyone tell me if there is a "better" bolt released by GM since 2002 to fix this problem?

Thanks for reading... just mad right now is all...

James

2000DV4.8 · October 7, 2008

I just looked at my manifold bolts yesterday, and as of now, they're all in place, but look so damn rusty that if you sneeze while working under there the head will pop off.

Darkanion · October 7, 2008

I just looked at my manifold bolts yesterday, and as of now, they're all in place, but look so damn rusty that if you sneeze while working under there the head will pop off.

RUST?! On YOUR truck!? Say it isn't so!!!

95Sierra2500 · October 7, 2008

It's what happens when you take every bolt and make it a torque-to-yield bolt. I'm convinced that the exhaust manifold bolts are over-torqued, and the repeated heating and cooling pops the heads off in short order.

I would suggest that, while your mechanic is in there, get some ARP studs/bolts for those manifolds and have him install those. I'll bet they're MUCH stronger than your current bolts and won't break off in 5k miles.

csheatz · October 7, 2008

I used to work for the company that coated almost every bolt/nut GM uses. The reason for the rust is that around the time of 2002/2004 GM kept messing with a new high heat paint. this crap sucked, we had to bake it on at 650 degrees, we had a few ovens catch fire, and other problems going through the learning curve with GM. When I left there in 06 they were still having a lot of trouble!

As for the bolts snaping off, I would think this is not common, a few samples from every heat lot (3000-5000 parts) are subject to hardness testing, if one fails they USED to scrap the whole lot! The bolts are engineered with the idea that when tightned to the proper ft/lbs the bolt should stretch, but should not lose it integrity. If its breaking that tells me it was over tightened.

ChrisNJ · October 7, 2008

I had two pop on an '02 truck, and the subsequent exhaust leak. Local mechanic charged me $170 to replace all the bolts, guess he and me got lucky that they all came out easy enough.

DSN46 · October 7, 2008

Thanks all.

I don't think it would have been even close to the ordeal that it is if the bolt that broke would have been even one more away from the firewall. It just HAD to be the one that is impossible to get to.

As of right now... he still has it at the shop. Been there since 06:45 hrs. today. He had to wait for the cylinder head bolts to get there from another town. So it basically took him no time at all to get it apart and drill the broken bolt out. It has just been sitting there torn down waiting for new bolts......

At least he knows NOT to re-use head bolts.

James

LawmanSS · October 7, 2008

Another vote for ARP fasteners!

Sinkhole · October 7, 2008

If I have to remove something on any of my vehicles, the bolts get replaced with ARP bolt 90% of the time.

Ryan00TJ · October 7, 2008

It's not just a GM problem. My 2000 Jeep TJ's exhaust manifold had two studs, one at each end of the manifold. The rest were bolts. The stud on mine closest to the firewall broke off causing a noticeable exhaust leak. It broke off flush and I could not drill it out. I had to pull the head and use an EZ out on my workbench. DC issued a TSB and revised lower torque sequence for the new studs.

satori · October 8, 2008

Howdy,

So I had an exhaust "knock" going on when the engine was cold. Once warm, it stopped.

Did I just say "who cares... leave it alone"... NO sir! O'l James just had to dig into it and find that my driver's side manifold was missing the rear-most bolt! Yep, broke off. Causing a small leak back there by the firewall. I could have just not looked and went on my merry way.

Now... my mechanic is taking apart my engine to remove the head so he can drill out the broken bolt.

He isn't screwing me or anything.. he gave an honest shot at getting at it with the head in place on the motor...just not enough room back there.

This little damned gem is going to run me $800.00.

What the hell was GM thinking when they made these bolts? How do you justify making a bolt that pops the head off while sitting there?

I just had to rant. I know others have felt my pain, and believe me I'm sorry you had to go through it also.

Can anyone tell me if there is a "better" bolt released by GM since 2002 to fix this problem?

Thanks for reading... just mad right now is all...

James

Were you hearing the noise up front, or back at the tailpipe? I ask because my '05 Tahoe (5.3L) makes a sound out the tailpipe like it's running under water for the first few minutes, then clears up. It's been driving me nuts.

geektoad · October 8, 2008

It's what happens when you take every bolt and make it a torque-to-yield bolt. I'm convinced that the exhaust manifold bolts are over-torqued, and the repeated heating and cooling pops the heads off in short order.

I would suggest that, while your mechanic is in there, get some ARP studs/bolts for those manifolds and have him install those. I'll bet they're MUCH stronger than your current bolts and won't break off in 5k miles.

I put ARP studs/nuts/locks on my 98 Camaro when I did the long tubes on it. That car was the definition of abused due to racing, and i never once had a leak or issue with the ARP hardware.

alaska511 · October 8, 2008

It's what happens when you take every bolt and make it a torque-to-yield bolt. I'm convinced that the exhaust manifold bolts are over-torqued, and the repeated heating and cooling pops the heads off in short order.

I would suggest that, while your mechanic is in there, get some ARP studs/bolts for those manifolds and have him install those. I'll bet they're MUCH stronger than your current bolts and won't break off in 5k miles.

I put ARP studs/nuts/locks on my 98 Camaro when I did the long tubes on it. That car was the definition of abused due to racing, and i never once had a leak or issue with the ARP hardware.

+1 on the ARP hardware, racing my mustang and the Chevelle and Camaro as daily drivers, they never let me down. As for stock replacement bolts, Pioneer has some decent hardware

DSN46 · October 8, 2008

It's what happens when you take every bolt and make it a torque-to-yield bolt. I'm convinced that the exhaust manifold bolts are over-torqued, and the repeated heating and cooling pops the heads off in short order.

I would suggest that, while your mechanic is in there, get some ARP studs/bolts for those manifolds and have him install those. I'll bet they're MUCH stronger than your current bolts and won't break off in 5k miles.

I put ARP studs/nuts/locks on my 98 Camaro when I did the long tubes on it. That car was the definition of abused due to racing, and i never once had a leak or issue with the ARP hardware.

+1 on the ARP hardware, racing my mustang and the Chevelle and Camaro as daily drivers, they never let me down. As for stock replacement bolts, Pioneer has some decent hardware

Hey thanks for info on the bolts guys!

If I ever need to crack into the passanger side, the ARP is what I will do. For now though, I went in last night and he showed me the "new" bolts from GM that came when he ordered them. They have a bigger head on them and look better anyway. Whether they are actually any better or not remains to be seen. It is at the Dealership by the way... I guess I didn't make it clear in first post.

Anyway, when I went in, he was taking the time to clean everything while he had it all apart. (something I dont think all mechanics take the time to do) It all looks nice and shiny again. He will have it ready this morning so we'll see if all is well, or better, than it was before.

James

DSN46 · October 8, 2008

Howdy,

So I had an exhaust "knock" going on when the engine was cold. Once warm, it stopped.

Did I just say "who cares... leave it alone"... NO sir! O'l James just had to dig into it and find that my driver's side manifold was missing the rear-most bolt! Yep, broke off. Causing a small leak back there by the firewall. I could have just not looked and went on my merry way.

Now... my mechanic is taking apart my engine to remove the head so he can drill out the broken bolt.

He isn't screwing me or anything.. he gave an honest shot at getting at it with the head in place on the motor...just not enough room back there.

This little damned gem is going to run me $800.00.

What the hell was GM thinking when they made these bolts? How do you justify making a bolt that pops the head off while sitting there?

I just had to rant. I know others have felt my pain, and believe me I'm sorry you had to go through it also.

Can anyone tell me if there is a "better" bolt released by GM since 2002 to fix this problem?

Thanks for reading... just mad right now is all...

James

Were you hearing the noise up front, or back at the tailpipe? I ask because my '05 Tahoe (5.3L) makes a sound out the tailpipe like it's running under water for the first few minutes, then clears up. It's been driving me nuts.

The knock from a loose or leaking exhaust is pretty obvious if you ever hear it. It is a definite "knocking" sound or "ticking" sound.... no burbling noises.

I think what you hear is consensation built up in the muffler getting blown out. Sometimes, an exhaust leak upstream can cause excessive condensation in the system, but I wouldn't worry about what you are hearing if I were you. I've heard that same sound an several vehicles I've owned.

James