Engine Whining Noise

Discussion in 'GM Powertrain' started by jwh1975, Apr 6, 2009.

  1. jwh1975

    jwh1975 New Member

    Hopefully someone has an idea on my problem:

    I have a 2006 Trailblazer LS with the 4.2L I6 Engine with 67,000 miles. I have a "whining" noise coming from the engine. It raises in pitch when I accelerate and never stops the entire time the engine is running. I have removed the belt completely and run the engine briefly, and the noise is still there. Upon using a cheap mechanics stethascope, the noise sounds like it is coming from the top front of the engine, inside the area where the oil filler cap is located, maybe around the cams? I have replaced both the tension idler pulley and the idler pulley with no success. Thoughts or suggestions...I have to fix this thing myself and I have never worked on this thing other than oil changes and simple maintenance (idler pulleys mostly).

    Thanks for ANY help anyone can give.
  2. Lightzz2k

    Lightzz2k New Member

    I know this post is a little old But Im experiancing the same sound on my 1988 C1500 with the 305.
    So if anyone has any input on this thread that would be awesome. I did the same thing took the belt off and the sound is still there. My engine has 150km on it.
  3. Lightzz2k

    Lightzz2k New Member

    I should also mention my truck sat for about 4 years and supposivly it did not do it before it sat
  4. daddytech

    daddytech Epic Member 5+ Years 500 Posts

    I have had this type of issue a couple times and i'll give you my examples and let you make your own assumptions as to what may actually be each of your personal issues.

    I had a 2000 Ford Taurus I got as a fixer upper a couple years ago. I had to do all new head gaskets , new freeze plugs, new wires , new transmission (that was fun by the way... NOT!)
    new coil pack, new rear Catalytic converter etc etc. I had to do the head gaskets on the front side twice because i didn't pay attention to the "UP" tag when i put the exhaust manifold back on and torqued it down properly one of the bolts caused the top piece of the #3 exhaust port to break off but it still sealed properly (or so i thought) I ran the car a while and it started whistling at me where the exhaust was blowing by the manifold and gasket I cheated since i was going to sell the car and just torqed it down a little harder than it should have been and the whistle went away.

    second instance. Shortly after getting my tahoe I noticed that it was whistling at me also (must be something with me and cars.) it was coming from the intake but I couldn't tell for sure where. it appeared to be coming from the AC compressor at first which kind of hangs over the drivers side of the engine. I figured at the time that it's just the ac compressor and i'd probably have to fix the leak and recharge it later. well the AC wasn't going down, to this day it still runs arctic cold to the point that it will actually frost the windshield in the summer time. a week later i got out convieniently at the parts store and heard what sounded like air coming out of my engine compartment. the truck was off so i had to find out what it was, checked the hoses and looked for leaks, nothing. kept searching and found the problem , I had coolant leaking up from between my manifold and head right underneath the ac compressor. $500.00 and 45 minutes later, i had new gaskets installed and was on my way. (my after hours GM mechanic is hella fast) I wasn't attempting that one because i was affraid of messing up the injectors or putting the distributor back in wrong.

    any how either of those types of things could be you two's issue or also a leak in a vacuum line could also cause that as well.. other than that something would have to be trying to sieze up on you and may be squealing for that reason. I would start by checking all the vacuum hoses for leaks or cracks on the ends and make sure they all have a good seat too. then check the hoses and also take inventory of the coolant to make sure none of it has disappeared. and then start looking at lubrication.
    Some things will squeak when the motor is cold because there is no oil in the top of the motor to lubricate them. this is why I usually recommend Mobil1 motor oil with Lucas addative that addative and the synthetics in the oil actually create a bond and keep all the components of your motor internals lubricated and quiet.

    If the noise were coming from the lower part of the motor i would suggest taking it in and getting the bottom end checked out. spun bearings and scored crank journals can cause that too but you wouldn't be hearing that from the top side.

    hope this helps either or both of you some how would help if you were able to determine if the nouse was coming from the outside of the motor or inside.

    post your resolutions up on here so that others can benefit from your experience too

    good luck
  5. Lightzz2k

    Lightzz2k New Member

    someone said to me last night it sounded like it was coming from some bearing in the bottom end, but because it has been sitting to do an oil change and add some lucus in and that should get rid of the sound. he said if i go a month without hearing it again it should be ok...does this sound right?
  6. jwh1975

    jwh1975 New Member

    Well, I know the noise gets a little bit louder if you remove the oil filler cap with the engine running, which leads me to believe it is something internal behind the front cover/under the valve cover. My guess is it may be something to do with the timing chain...either a tensioner or the idler sprocket, in either case, I have no warning lights on the dash, it's not using any oil or coolant...it's just annoying. I will probably investigate it in depth this summer when I can take some vacation time to do so. I only have one vehicle, so I can't have it down too long.

    Thanks for the suggestions, and I will post what I find as soon as I find something. :)
  7. 2ToNe04

    2ToNe04 Epic Member 5+ Years 1000 Posts

    someone put a turbo while you werent looking lol or maybe a secret spacer.
  8. daddytech

    daddytech Epic Member 5+ Years 500 Posts

    hope it's not anything serious like a main seal but i wouldn't be running it either, if it's squealing and there is nothing that you can put your finger on directly you can wind up scoring or doing major damage to something in the motor if you run it that way much or for very long.
  9. Lightzz2k

    Lightzz2k New Member

    im not running it really just to pull it in and out of the garage. Its got along way to go before its on the road. It runs good though when i drove her home no hesitation or anything so it just seems wierd to me.
  10. grimreapersshadow

    grimreapersshadow Rockstar 100 Posts

    proalby just your timing chain from the lack of useage and no oil setting on it during the long months

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