How to ID a bad part
Thread Starter
Instructor
Joined: Mar 2007
Posts: 174
Likes: 0
From: Lithia FL
How to ID a bad part
New owner of an '88 and except for the frisbee removal it's a completely stock engine bay. On yesterday's cruise I started hearing a knocking clatter coming from under the hood. Almost like a bad bearing sound to my very untrained ear.
My problem is I can't identify the part that is making the noise. Water pump, alternator, air pump, AC Compressor, Power steering. I believe it's one of these bolt on parts or maybe I am hoping.
My question is how do I id the noisy part, I read somewhere about using a doctor stethescope? Here is what I have done to try and isolate:
Alternator is brand new
Sound does not change when I turn the wheel
Sound does not change when I change engine RPM
Sound does not change when I turn AC on and off
Any tips would be appreciated.
Thanks
Bob
My problem is I can't identify the part that is making the noise. Water pump, alternator, air pump, AC Compressor, Power steering. I believe it's one of these bolt on parts or maybe I am hoping.
My question is how do I id the noisy part, I read somewhere about using a doctor stethescope? Here is what I have done to try and isolate:
Alternator is brand new
Sound does not change when I turn the wheel
Sound does not change when I change engine RPM
Sound does not change when I turn AC on and off
Any tips would be appreciated.
Thanks
Bob
Team Owner
Joined: Jan 2003
Posts: 20,326
Likes: 252
From: Summerland B.C. Canada
Try a piece of garden hose as a stethoscope. Removing the belt and spinning the parts by hand may help too. Look at the air pump and tensioner, those 2 made some nice sounds on my vette. 
