Cold start engine noise

Medic3166

Original poster
Member
Mar 26, 2017
11
NJ
Link to video:https://streamable.com/2leuu

2006 GMC Envoy 4.2L I6, 64,000 Miles.

The high-pitched metal-ish noise only appears on cold starts, and goes away once the engine is warmed up. The noise will increase in speed with an increase in RPMs. I suspected a pulley, but it sounds like its coming from the rear of the engine. The video is taken from under the passenger door area.

Thanks!
 

mrrsm

Lifetime VIP Donor
Supporting Donor
Member
Oct 22, 2015
7,642
Tampa Bay Area
Invariably... high pitched rhythmic, metallic squeaking noises can be traced to bad Idler Pulley Bearings, Belt Tensioner Pulley Bearings and even carrier bearings in the Alternator as well. The fastest way to either confirm or eliminate this specific dry, worn bearing issue is to temporarily remove the Serpentine Belt and start the Engine and listen for a very brief period... lest you run the battery too far down. On rare occasions... misaligned pulleys will rapidly grab and release the belt and cause it to chirp. Start with this test ... and if the annoying noises subside... consider replacing both the Idler Pulley and the Belt Tensioner. And please... use only OEM Quality AC-Delco or GM replacement parts here.
 
Last edited:

Forum Statistics

Threads
23,273
Posts
637,499
Members
18,472
Latest member
MissCrutcher

Members Online