Ticking or clicking noise when accelerating - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

elwoodblues · #1 05-04-2009, 07:19 AM

I get a light ticking or clicking noise when I begin to accelerate that I can hear in the cab. The truck runs fine, and when I get up to my cruising speed, the ticking goes away. Any ideas or is this standard?

the roadie · #2 05-04-2009, 09:34 AM

Could be many things. How many miles on the vehicle? If you stop accelerating in the middle of getting up to speed, does the noise stop? We need to separate out engine-related causes from driveline causes. Engine issues are in the serpentine belt, idler pulley, and fan shroud/fan/water pump areas. Driveline issues might be in the hub bearings, CV shafts, transfer case, driveshaft, or rear differential. Any chance somebody can drive next to you as you speed up and see if the noise is from the front or rear?

elwoodblues · #3 05-04-2009, 09:43 AM

Quote:

Originally Posted by the roadie

Could be many things. How many miles on the vehicle? If you stop accelerating in the middle of getting up to speed, does the noise stop? We need to separate out engine-related causes from driveline causes. Engine issues are in the serpentine belt, idler pulley, and fan shroud/fan/water pump areas. Driveline issues might be in the hub bearings, CV shafts, transfer case, driveshaft, or rear differential. Any chance somebody can drive next to you as you speed up and see if the noise is from the front or rear?

85K miles. Noise is coming from the front of the vehicle. I guess I should probably just bring it in to the mechanic. I need to have the AC checked to see why that is not working.

ylab · #4 05-04-2009, 10:23 AM

Are you sure its in the front of the vehicle and not the dash? - There's been a history of noisy instrument clusters, if the noise only occurs at elevated engine speeds, trying reving in Park/Neutral and see if you hear the ticking. (Might be the tach stepper motor).

Also up the hood and listen there, if the noise duplicates in Park/Neutral and is from under the hood, you may be able to partially isolate the source. If its along the top of the engine, might be injector noise....they do sort of tick or click normally, but get louder when dirty or partially clogged. (A good injector cleaner will lessen the noise, if this is the case). If the noise is from the front of the engine, might be the clutch fan, idler pully or even the a/c compressor bearing.....you did mention the a/c doesn't work. (Might not be coincidence).

elwoodblues · #5 07-17-2009, 10:53 AM

Okay, AC is fixed, was just low on coolant not allowing the compressor to kick in, whew.

Anyways, I tried to rev in neutral/park and the ticking doesn't occur. Only when in gear and accelerating. Any ideas? I don't hear it once at 60 mph cruising, only seems to be above 2000 rpms

playstrings · #6 08-14-2009, 06:33 PM

Hmmm - is the vibration at your feet ?
When you move the wheel from side to side does it change pitch?
I have had this issue recently and it is in the front diff.!!!

Good Luck !!
Rick

elwoodblues · #7 08-17-2009, 09:54 AM

Found out it was a cracked exhaust manifold.

the roadie · #8 08-17-2009, 12:03 PM

Fascinating. Thanks for coming back to report that. We'll add it to our suggestion list for future questioners.

1_loud_trlblazr · #9 09-16-2010, 01:11 PM

i get this sound too, but it is only when i first take off. it also does it when i am in reverse. any ideas?

Kristis Dad · #10 09-16-2010, 06:02 PM

had the same when I got ours, heard it gettin on xway. Acceleration under load= exhaust leak, mine was the rear bolts snapped...