Search | Car Forums | Gallery | Articles | Helper | AF 350Z | IgorSushko.com | Corporate |
| Latest | 0 Rplys |
|
Problem Diagnosis Got a problem you can't fix? Post here and one of our members will answer as soon as possible. |
Show Printable Version | Email this Page | Subscribe to this Thread |
|
Thread Tools |
06-08-2012, 04:27 PM | #1 | |
AF Newbie
Join Date: Mar 2005
Location: St George, Utah
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
|
Startup engine noise
I have an 02 Blazer w/ 110K miles. It's the 4.3L with 4WD. When I start it in the morning it usually has a low pulsing whirring sound for up to 30 seconds. It then goes away until the car is parked for a long time again, say overnight. It's a low volume sound, a lot like the sound of off road tires running down the highway. This has been going on for several months now.
All systems work fine. The alternator is new, the water pump has about 29K on it, and the top idler pulley has been replaced. Turning the A/C on or off makes no difference. The sound is loudest when you stand in front of the passenger side headlight which made me suspect and swap the alternator. Anyone ever heard of this? Could it be the belt? It was replaced with the WP and the ribs are not smooth inside. They are notched. I assume that's to improve the flexibility of the belt. If I take it to a shop they'll get 30 seconds each morning to diagnose it. Yikes!! Any help will be greatly appreciated. |
|
06-09-2012, 08:00 AM | #2 | |
AF Enthusiast
Join Date: Oct 2011
Location: Ft Lauderdale, Florida
Posts: 953
Thanks: 13
Thanked 121 Times in 120 Posts
|
Re: Startup engine noise
Run the cold engine briefly without the belt... noise, no noise? Check each pulley by hand for bearing roughness, side play, etc. Repair/replace as needed. Replace belt. HTH
|
|
06-10-2012, 04:02 PM | #3 | |
AF Newbie
Thread starter
Join Date: Mar 2005
Location: St George, Utah
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
|
Re: Startup engine noise
Thanks. I'm a bit embarrassed that I didn't think of that myself. I'm now suspecting the tensioner pulley. S/B cheap to try.
|
|
06-10-2012, 05:10 PM | #4 | |
AF Enthusiast
Join Date: Mar 2008
Location: garner, North Carolina
Posts: 3,579
Thanks: 86
Thanked 100 Times in 100 Posts
|
Re: Startup engine noise
Doe's this truck have hydraulic lifters, or cam followers?
|
|
08-14-2012, 03:56 PM | #5 | |
AF Regular
Join Date: Jul 2004
Location: hometown, Washington
Posts: 142
Thanks: 18
Thanked 0 Times in 0 Posts
|
Re: Startup engine noise
No blowers dont know about the lifters. stock 22re.
Suspecting the a/c or alternator after thinking I am leaning more towards the a/c cause I have never heard of an alternator making noise. A/c could just be coincedense happened now. |
|
08-15-2012, 11:34 AM | #6 | |
Big Tall Dumb Ass
Join Date: Dec 2003
Location: Deep Dark Doo-Doo
Posts: 1,300
Thanks: 15
Thanked 27 Times in 26 Posts
|
Re: Startup engine noise
This could be the notorious belt noise problem. I have intermittent belt noise upon initial start up on my 2000 Jimmy SLE 4.3L . I have found that a brand new belt will eliminate the problem. I try to stick with the Gatorback belt. You will chase the frikking noise all over the belt drive system, so before removing and replacing ANY belt driven component, take a good look at the belt first. If your belt is more than about 2 years old, replace it for good measure and see if the noise stops. Running the engine without the belt and Spinning bare pullleys by hand is a good idea but won't reveal the problem if it is the belt to start with.
__________________
"If everyone is thinking alike, then no one is thinking". - Gen. George S. Patton Jr. |
|
08-15-2012, 02:22 PM | #7 | |
AF Regular
Join Date: Jul 2004
Location: hometown, Washington
Posts: 142
Thanks: 18
Thanked 0 Times in 0 Posts
|
Re: Startup engine noise
OOPPs! Sorry wrong thread. Not sure how I did that.
Sorry guys |
|
08-20-2012, 09:59 PM | #8 | |
Advisor/Moderator
Join Date: Nov 2005
Location: Belleville, Michigan
Posts: 5,184
Thanks: 6
Thanked 103 Times in 95 Posts
|
Re: Startup engine noise
Possibly the AIR, (Air Injection Reaction) system, sometimes called secondary air. Pump is on the back of the alternator, maybe one of the check valves burned up or a hose came off. Just a thought Is the SES light on? Do you have any DTC's in memory for secondary air?
__________________
You have to know how it works, to figure out why it doesn't. |
|
|
POST REPLY TO THIS THREAD |
|
|