: 2002 Escalade 6.0 Stock Exhaust Buzzing, Moaning between 2,500 and 3,000 RPM



RLGDiesel
07-09-09, 02:02 AM
Hello...I own a 2002 Cadillac Escalade AWD 6.0 with 80,000 miles. It's been a great truck but recently developed an odd sound in the exhaust when accelerating from a stop/coast/roll only between 2,500 and 3,000 RPM. It seems to be a louder and rougher sounding buzzing, moaning, or humming sound. Could this be a resonator failing...does anyone have a similar experience?

P.S. It doesn't really sound like a heat shield to me.

fijijason
07-10-09, 01:45 AM
Got the same exact issue but Im running a cat back corsa touring system. I was thinking that the cat had cracked/broke causing it to vibrate at a certain pressure or RPM. Any ideas would be great! Thanks J

luxurylife33
07-10-09, 02:01 AM
maybe jack the car up and rev from idle to 3k to simulate stop and go? lift the hood up or take a peek underneath.... have some backup stands in case the stands give under vibration.

stealth09
07-10-09, 09:54 AM
Same thing here, after the dealer replace my u-joint. I think it is a heatshield.

ESCALADOR
07-10-09, 10:04 AM
Got the same exact issue but Im running a cat back corsa touring system. I was thinking that the cat had cracked/broke causing it to vibrate at a certain pressure or RPM. Any ideas would be great! Thanks J

Funny this subject just came up! I had the exact same issue last night. I have the Corsa Touring system installed on my Lade as well and was getting the vibration and moaning sound, I was like damn! my Touring just turned into a Sport! After jacking the car up and securing it with stands I inspected everything and finally noticed that the clamp securing the pipe from the muffler back to the tips was completly loose and the pipe was just about to come off!! I tightend down the clamp and everthing is back to normal.

I had the Touring system installed on the truck around a year ago. I am going to keep an eye on those clamps from now on! :alchi:

RLGDiesel
07-11-09, 06:24 PM
Thanks for the replies...only occurs under load (so I don't think the revving will duplicate the sound) but I will definitely check the exhaust brackets, clamps, and heatshields carefully. Has anyone had the problem with stock exhaust?

stealth09
07-15-09, 01:13 AM
Yes I had it with stock exhaust. Turns out a shield by the muffler was touching. The exhaust shop bent it up and out of the way for free.

pcguy760
07-24-09, 03:38 AM
Yes I had it with stock exhaust. Turns out a shield by the muffler was touching. The exhaust shop bent it up and out of the way for free.

My Ford did that too and this is exactly what was done to stop it - you guys should look into this idea first...

sk7
07-24-09, 05:42 AM
Same here. Shield on factory exhaust was loose. That was taken care of when I replaced the unit with Corsa sport! I did check the clamps after about 100 miles, since its highlighted in bold letters in the install instructions, and they were all loose!

ponicg
07-24-09, 11:18 AM
Yep. Same here. The dealer just put a clamp on it and didn't even charge me. Thank god for CPO:)

RLGDiesel
08-10-09, 08:24 PM
UPDATE: I took the car to a GM dealership today and they examined the exhaust system with me. When the tech hit a portion of the pipe behind the cats, the metal ring above the O2 sensor vibrated and rattled throughout the whole pipe. However, after replacing the O2 sensor, the buzzing and moaning persisted at the same RPM range. I mentioned the heat shield and clamps, but the tech could not duplicate the sound when tapping the muffler with a rubber mallet. Just to be sure, is this something you all heard under engine load and was it sporadic? Do you think it could also be a muffler baffle gone bad? Thanks in advance!

EscaladeDave
09-11-09, 11:55 AM
I have the same problem...I suspect a baffle.

RLGDiesel
09-12-09, 03:42 PM
FIXED: Hole/leak in muffler replaced with a Corsa touring system