Main IndexAuto Repair Home Search Posts SEARCH
POSTS
Who's Online WHO'S
ONLINE
Log in LOG
IN









Whine in engine


  Email This Post



plkelly
New User

Sep 11, 2011, 3:49 PM

Post #1 of 8 (2377 views)
Shortcut
Whine in engine Sign In

I havean 04 Trailblazer w/4.2. I have an engine whine that sounds electrical. I am a retired auto mechanics teacher, current ASE certified. I repalced the alternator because it definately sounded like it was coming from the alternator. I used a stethescope to listen to the whole engine. The whine increases with acceleration. It has a new belt and battery. Fan clutch engagement does not affect the noise. Water pump seems to be tight and its not overheating or throwing any codes. As I said, it sounds 100 % electrical. Car runs fine. Since it has the serpantine belt, I can not remove belts too eliminate the noise. The PS pump is quiet. I couldn't find any TSBs on it. Any ideas?


(This post was edited by plkelly on Sep 11, 2011, 4:12 PM)


Discretesignals
Veteran / Moderator
Discretesignals profile image

Sep 11, 2011, 3:51 PM

Post #2 of 8 (2375 views)
Shortcut
Re: Whine in engine [In reply to] Sign In

If you unplug the alternator's electrical connector, does the whine go away?

Since you are a retired automotive instructor are you testing us?





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Sep 11, 2011, 3:58 PM)


plkelly
New User

Sep 11, 2011, 4:11 PM

Post #3 of 8 (2356 views)
Shortcut
Re: Whine in engine [In reply to] Sign In

I am not testing you. I have never had a problem like this that seems to defy all logic. The noise does not go away when unplugging the alternator. Any other ideas?


re-tired
Veteran / Moderator
re-tired profile image

Sep 11, 2011, 7:23 PM

Post #4 of 8 (2330 views)
Shortcut
Re: Whine in engine [In reply to] Sign In

Try unplugging the electric air pump before starting engine.,


LIFE'S SHORT GO FISH


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Sep 11, 2011, 7:24 PM

Post #5 of 8 (2330 views)
Shortcut
Re: Whine in engine [In reply to] Sign In

You should be able to remove the belt at least long enough to see if the noise is still there or not so you will know for sure if it is a belt driven component or not. It's probably an idler pulley, tensioner pulley or something like that.




~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Discretesignals
Veteran / Moderator
Discretesignals profile image

Sep 11, 2011, 7:32 PM

Post #6 of 8 (2325 views)
Shortcut
Re: Whine in engine [In reply to] Sign In

I agree with HT. You should be able to remove the drive belt. There were a couple of hits on IATN for the fan clutch making a whining noise. They had a TSB on the fan clutch wiring harness chaffing (TSB 05-06-02-012B).

Did you scan the PCM for trouble codes? If so, what is being stored? If you have a scan tool with bidirectional control, you can command the fan clutch to check its operation and to see if the noise changes.

I thought about the AIR pump too, till he/she stated that the whine noise increases with engine rpm.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Sep 11, 2011, 7:38 PM)


plkelly
New User

Sep 11, 2011, 9:15 PM

Post #7 of 8 (2311 views)
Shortcut
Re: Whine in engine [In reply to] Sign In

Worth a try.


plkelly
New User

Sep 11, 2011, 9:18 PM

Post #8 of 8 (2309 views)
Shortcut
Re: Whine in engine [In reply to] Sign In

No PCM codes. Don't have a sophisticated scanner. I might borrow one. Thanks




Advertising


  Email This Post
 
 






Latest Forum Post

I recently blew an engine-'01 CHEV SILVERADO 5.3L-& had an '02 5.3L transpla...


hi, my engine still runs after i turn the key off then dies after few seconds, w...


I have a weird situation in that my run lights won't work on my utility trailer....


My 1995 Nissan Quest starts just fine. When I depress the brake pedal and move t...


I have a 1992 ford ranger 3.0l v6 5 speed. today i ran out of gas and when i got...


Hi there! I had a problem with my clutch, removed the transmission and need to ...


Feed Button






Automotive Forum Categories
AC Auto Repair
Auto Body Repair
Auto Insurance
Automotive Repair
Automotive Wiring
Automotive World
Brake Systems
Car Care Tips
Car Racing
Car Shows and Events
Car Stereo Repair
Car Troubleshooting
Engine and Car Noises
Engine Fault Codes
Engine Troubleshooting
Exhaust System Repair
Gasoline and Motor Oils
General Discussions
Motor Vehicle Inspection
Motorcycle ATV Repairs
Motorcycle Body Repair
Motorcycle Clutch Repair
Motorcycle Engine Repair
Motorcycle Repair
Motorcycle Seat Repair
Remote Control Cars
Steering and Suspension
The Bargin Bin
Traffic Ticket Help
Tricks of the Trade
Truck Repair
Truck Repair Advice
Truck Engine Repair
Truck Suspension Repair
Car Forum - Sitemap


Search for (options) Privacy