I have an 00 Max with 198,000 miles...Yes.. You've read right.. I've been hearing this knocking, rattling sound coming from the right side engine bay (right side when sitting behind the steering wheel) Any ideas on what this can be? The knocking goes away after a while, not noticeable as I'm driving, but sometimes you can hear it again when at a traffic light. Engine oil has been changed regularly, don't think its the motor. What else could be making this sound?

Also need to change the belts on this puppy, how do you know when the idler pulley is going bad? Does it make any noise, any tests to perform for this?

 

Take a look at it when it's idling. (Right side, belts, idler pulley, etc)

 

I've tried that...I can't hear anything or see anything that looks out of place... I was browsing some links and read where some guy said his alternator bearings were making a knocking sound...could this be it.... also, how can i check the idler pulley.. i hear that they often go bad, and i need to change my belts so i might as well change it too if its bad...just don't know how to determine if its bad....again, this car has 198,000 miles, so who knows what could be wrong....

 

If it wobbles, or the bearing is destroyed & makes noise.

Also, the threaded adjustment rod on it will probably snap on you.

Automotive stethescope from sears ftmfw.

 

ok. I have purchased the scope.. will test everything in the am....

 

i have the same noise. and it seems to be the ac compressor, the clutch
even though the air isnt on the pulley still has to rotate. i believe the clutch goes bad and sticks in between engaged and not. i thought it was my idler pulley/tension pulley but after cutting the ac on and off i was able to isolate it. can be bad news if the clutch locks up. but not trying to scare u

 

everytime I hear someone complain of noise in that area...ESPECIALLY with alot of miles....it's the timing chain. by 198k the chain is stretched and the tensioners and guides are worn out. this creates noise. i'd be surprised if it's something else.

 

Sounds like it to me as well. Similar noise in my old 626, a knocking sound at idle that went away at around 1800 rpm. Turned out the tensioner was completely shot and the timing belt nearly fell off when my mechanic pulling the timing chain cover. New belt, tensioner, etc and it was all quiet again...and one month later, my car got rear-ended and totaled. $700 down the toilet.

 

we are all just putting in our 2 cent. mine was the compressor. if it is the compressor clutch you can look down at the pulley and see is hesitate as it knocks.

 

Its probably all of these, my motor sounds like *** lol. Ac compressor clutch is making plenty of noise, it has since 80k when i bought my car (now at 140k). Loud *** DE-K injectors, and noisy timing components.

 

3 POINTER!

 

Easy way to find out if it's an accessory or if it's something else - pull the belts one at a time, crank the car back up and listen. If the noise goes away - congrats - you just narrowed it down. If it doesn't go away, it could be the timing chain. Good luck.

 

Harmonic balancer ? mine took a dump and it clunked , replaced it and its quiet now.