Annoyances Dealer Unable to Fix

[Dusterman]

I've had my '03 Silverado (1500 4x4 w/ 4.8L and plow pkg) in several times for two problems they have been unable to address thus far. Let me know if you guys have experienced this problem or have a remedy....

 

1. High frequency whine, (usually constant, although sometimes intermittent) coming from underhood at 800-1000rpm that sounds like a squeeky serpintine belt. Dealer has replaced belt but I suspect it may be an accesory bearing(?)....

 

2. Under moderate to heavy throttle I get a rattle that sounds like an exhaust sheild. The dealer put clamps (service bulletin I believe) on the muffler sheild but it hasn't fixed the problem. Any weird spots I/GM should check?

 

 

Thanks!

 

Dustin

 

 

(I heard about the plastic engine cover causing rattles, haven't checked it out yet)

[JimG]

Hi,

 

You know, I definitely think I have the same problem #1 as you do. I haven't taken it to the dealer for this yet. Wasn't sure how common a problem this is - I read somewhere about the alternator bearing ... you might want to search for that.

 

Jim

[Imkunfused]

Be proactive and crawl under the truck and hit around on the heat shield.. you will find its either hitting the bed, or hitting the muffler, or something else.. grab it with a pair of pliers and bend it around the problem.. Why take it in for stupid problems like that. Just because it shouldnt rattle, doesnt mean it wont.. sometimes its just better to do things yourself.. As for the whine under the hood.. a bearing could be going out.. set the throttle at that rate that causes the problem and pop the hood.. a long peice of metal (12-18 inch rachet extension) and start placing it on items under you find the noise to be the worst. There are numerous things that could be causing the problem.. Pullies, ac compressor, alternator, ps pump, fan.. or the tensioner

[silverado4800]

Yeah mine has that underhood whine too. Acts just like you describe yours, im going to find out the problem one day when i get some time. I suspect the belt or an accessory. I will post if i find out what is causing the noise.

[Dusterman]

Thanks for the advise Imkonfused , but Im used to doing that on my '91 explorer.....not my 2003 silverado. I guess my frustration is in the dealer's problem solving capability, or lack thereof.

 

What do the auto techs get paid these days? Maybe should figure out the problem myself and send Generous Motors the bill.

[bfrd22]

Generally I have found that if the ECU can't tell them what's wrong, their lost.

[mikez]

I have a 2003 GMC SIERRA with the 5.3L and it makes a sound that is similar to what you are describing in #1. I took it upon myself to find it and i did. It is a whistling sound that appears to be coming from the intake so I removed the pcv valve from the drivers side valve cover but left the hose attached to it and plugged the pcv valve with my finger and the sound goes away. I think that this is normal and it is just so much vacuum pulling so much air through the pcv valve that it whistles. Try this and see if your noise goes away while holding your finger over the pcv valve.