Well, here's another question that I have been chasing for the last 4 years since I have had the truck. When idling, it has a very annoying vibration/rattle. This is coming from somewhere in the exhaust, because if you add just a touch if throttle, it goes away.

As you all know, these things have more heat shields than the space shuttle, so they are always suspect but just when I think I have found the culprit, it starts again.

Anyone else had this?

My truck is a 97 H-1 2 door model with the 6.5 non turbo.

 

Not really but UCP, heat shields and muffler hangers are all prime suspects. Have you tried putting neoprene washers between the bolts and the above potential offending items?

 

i would say one of the welds on the exhaust crossover pipe cracked,(that is the pipe that is under the center of the vehicle and crosses over right in front of the trans pan) or it is a broken right exhaust manifold heat shield. those are the two common ones.

 

Thanks.

This will probably be your laugh for the day, but is there any good way to look at or get to those two items to diagnose or fix? For such a large hunk of truck, they seem to be the most cramped where it matters, especially with the underbody cage.

Any advice on this would be appreciated. Thanks.

 

2door, now that I think about it I did have an annoying vibration on the 97 that turned out to be the UCP was slightly bent up to where it made very slight contact with the exhaust system. You might look at that also.

 

you can start the engine, keep it in park and get under the hummer in the front engine area and listen for the rattle. both can be reached from under the hummer.
3 hummers is also correct that a bent up drive line protection intermediate section making contact with the exhaust crossover pipe will also cause a rattle.

 

My money is on a cracked heat shield - the good news is that rattles at idle are easy to find.&nbsp\\; Turn thr truck on, chock the wheels so they won't go anywhere under any circumstances, get under it, and use a long pry bar or screwdriver to poke the areas where you hear the rattle.&nbsp\\; When you touch the right spot and the rattle stops, you will know what part is the culprit.&nbsp\\;
&nbsp\\;
Good luck...