help grinding noise
 

99 Checy Blazer 4.3 automatic 4x4
Need help or ideas at whits end, low on cash, patience gone and noise still there. Any help appreciated. Had Motor Replaced 3 months ago, within a 1-2 weeks started hearing intermittent noise, concerned it was the motor (was a used motor) Noise would describe as a grinding, sound like a noise a dry or worn bearing would make. Metalic in nature, definte moving /rotating part. Noise at times is quiter than others but pitch seems same. Can hear in cab real well, but not from outside. Dont notice at speed/highway mostly lower speeds around town and when coming to a stop, will also make noise in park. I have tried killing motor when going down the road and noise stops, so ruled out brakes, suspension ect. Noise/pitch doesnt seem to change with rpm, can rev motor and noise seperate from engine noise . At first I though power steering, when in park and I noticed noise I played with wheel, noise would stop when turning one side to other for a certain distance in turn and then return. Fluids fine no steering issues when driving, mechanic states not the PS. Said bearing in alternator where worn also play in tension pulley and worn belt, replaced. Still have noise. With the belt off the idler pulley had some grind when turning, but seemed to turn fine with no binding, replaced anyway. Still have noise. Other issue is noise in intermittent, mechanic cant hear, so took to someone else (better hearing hopefully) Dam thing wouldnt make noise and they couldnt find anything that would contribute to making the noise. Other than the idler pulley , hence why I replaced. Dam thing still making the noise. Any ideas? Ive blown my christmas bonus trying to fix. I mentioned the motor replacement as it was not making noise prior to so might be relevent. Thinking it could be one of following: fan clutch, Power steering pump, water pump or possiblly ac. Having heater on does not effect, nor does AC. Doesnt seem to make noise when I first start in the morning and is cold. (real cold/ below freezing from sitting at night) But starts after it has warmed up and then for rest of day , on lunch break ect. The first mechanic did state the fan clutch seemed weak, second mechanic didnt mention and he did look at it . IDEAS

You said it was making noise when in park, and when coming to a stop, it wasn't brakes, was it coming from the transmission area or engine area?

Sounds crazy can you make youtube sound clip?

AC clutch?

not sure If I can do sound clip, will try. Yes making noise in park and coming to stop or driving at slower speeds. I think noise is just noticable during those times (less road noise??) No dont think drive system can turn key off going down the road and noise still there. Not sure on engine or tranny area. I notice in cab and when I step out its not as loud. Shifting from reverse to drive, park ect doesnt seem to effect or reving engine. Im leaning toward the fan clutch not sure if a way to check without just replacing.

On the AC clutch would there be a difference in noise or pitch when turning on AC? As having AC on or off doesnt seem to effect. ?????????????

Sorry on previous post I typed incorrect, when I turn off key going down the road noise stops.

On the AC clutch would there be a difference in noise or pitch when turning on AC? As having AC on or off doesnt seem to effect. ?????????????

Why is it called catsup when it drops down? Because cats always land right side up:)

Try taking a heater hose or something of the like, and go to areas that you think are the cause, and use it as a stethoscope, and touch the hose to the areas. Hope that works.

Btw, since I'm new to this forum, how do you make your own post's on here?

When you hear the noise, pull over & remove the serpentine belt, then fire it up again briefly & see if the noise is still there. That will rule out all the belt driven accessories. Keep in mind, your water pump will be stationary, and your ignition will run off the battery, so don't go for a drive & don't run it for too long - just to see if the noise stops. If it's still there, then it's an internal engine issue.

Check your backing plates around your rotors, look for rust and stuff stuck around your abs sensors. From there look at all motor and tranny mounts. Check that their tight , look for metal on metal. After all that start looking at exhaust and its hangers and clamps. See if there are hitting or too close to anything. ---- By chance are things different between 2wd and 4wd.


Re-read post! -- start with motor and tranny mounts!! then exhaust stuff. -- Rocks between sheilds and body / frame???? .. got confused,, Nickle ,, your post is a little hard to read!!

Smitty, it very well could be a transmission issue.