Hope someone can help. My 2096 hummer h3 has developed a clunking/knocking noise while car is in drive but stopped like at a red light. I got no warning indicators or anything from the dash. Still drives fine I sense no binding or anything. Only hear noise while in drive and stopped. Any suggestions would be helpful. Thank you!

 

Check the heat shield bolts to see if they're loose. Mine were and at a certain rpm I heard a knock/rattle from the front right engine compartment.

 

I'll take a look however it does not sound like a heat shield problem. I was low on oil so I added two quarts and it seemed to help but sound is still there. Might be time to flush tranny as it has not been done yet. Just turned 71k miles so it's probably time. Thanks to all who replied

 

If you search out you complaint, you would find that the majority of the time it turns out to be either an exhaust manifold heat shield (right side of motor) or CAT heat shield (right side of vehicle).

I would be more concerned about going 2Qts down in between oil changes than a noise. Mine never burns a drop.

Good luck.

 

Gomer,
Mine too has begun burning oil. With all the other issues the vehicles been having, I've been told it's symptoms of a bad cylinder head. Havent performed compression test yet, but I figured I share that with you. Mine is a 2006 as well.

 

Well gee I hope not the cylinder issue but guess it could be because I think my vin falls in the range. Ugh. Maybe if I have fm do a tune up they will let me know and cover it. (Lol right huh?)

 

Check your front differential bracket bushings. You can use a pry bar and see if they have enough play to hit your chassis or Rock your truck back and fourth while it's parked to try to reproduce the thumping. And I'm not referring to the center differential bushing, but don't forget to check that out too.

 

my hummer had same sound it's the FRONT differential bushing assembly. Dealer cost is over 650 to repair. Hope this Helps. Do it or end up buying a transfer case and that's $$$

 

Wow this was 2 years ago. I'll give ya an update. The clunking was my catalytic conveter that went out or whatever they do. Took it to dealer and they said I also needed a exhaust manifold also as mine was cracked. Not sure I believed them but had them change it anyway. Then I had a cheaper shop replace the converter under the passenger side. All was good for a while then had to get a new transmission as that went out as well. As of today all is well and running like a champ.

 

Thanks for the follow up... glad to hear its all good