lit549

Ok,i have a humming noise from belts on a 3.0 v6..I've searched everywhere and all posts say it's either power steering or timing belt..Mineconly does it at idle,it goes away as ya rev it,turning steering wheel has no affect..I recently replaced oil pump due to oil leaks and I inspected everything..There was rubber collected around plastic cover like the belt has been rubbing..After further inspection,it isn't rubbing cover anywhere..One edge of belt looks to be rubbing raised edge of water pump pulley..The belt and pump have 3k miles on them..Its a mitsobishi belt and aisen(?) pump..I installed new oem tensioner while in there..I know this humming is coming from belt cause when I pull inspection plug from cover it gets louder..Any suggestions???

lit549

I've looked and looked and can't find it..I'm stumped..

slowcivic2k

When did the noise start, and what was the last thing done prior to the noise appearing?

lit549

That I can't tell you..I bought the car in December for my daughter..Its been setting till she can drive..it has 110k on it and is clean..It had oil leaks which ended up being the oring on oil pump and cam cap o ings..I replaced pump and resealed everthing,the timing belt has 3k miles along with water pump,all oem...It sounds like a pulley is rubbing the plastic cover,but I couldn't find any place where it is rubbing..Also,i replaced belt tensioner and a serpentine idler pulley,still has the sound..Oh,water pump and alternater both turn freely without any bearing noise..

poorman212

For giggles, remove the serp belt and run the engine to be sure the noise is still there.......yes the alt won't be running but the wp will so just don't over do it but the car will be fine without the serp belt for a short period of time.

If it is still there....well then you know it is behind the covers and they will have to come off.

There are two "idlers/tensioners" there, inspect those for hard spots. Also there is a washer" on the crank where the concave should be facing out - is it?

beocop

Mine had a humming noise around the TB area. The sound is pronounced when one of the inspection plug on the TB cover is removed. It turned out to be the timing belt. The sidewall of the TB belt was rubbing and there was some metal showing on the sidewall of the belt. I don't know why the sidewall rubbed off. At that time, the TB only had ~12K miles. With the new belt on, the noise went away and hasn't come back yet.
Hope this helps. Good luck.

lit549

That's what I'm worried about,I was just in there too and couldn't see anything wrong at all..Everything is new you can tell,Now I wish I would have at least replaced the belt..I'm real curious as to why its wearing on one edge of belt?And as far as tension,its a auto tensioner,no adjustment..Guess I'm just gonna run it!

slowcivic2k

Ensure the timing belt guide plates on the crank gear are not installed backwards. Installing them backwards will result in the plate rubbing and tearing the belt up. There are two washers on this pulley. One behind, and the other in front. The tapered edge of both need to point away from the belt to prevent damage. If this is the case, when you disassemble the timing components you will notice a removal of the zinc plating on the washers.

A lot of people screw this up.

lit549

There was only one tapered washer ( guide plate) and i installed it correctly..

beocop

It could just be a "bad" belt. It could also be from a "wobbly" pulley. Over time, the belt edge gets worn down from an imperfect pulley movement.

lit549

How worried should I be? It only has 3000 mi on this belt..All pullies and water pump..I sure hate to tear it down again ,install new belt,and it does the same thing. I even replaced tensioner when I was in there.

lit549

I love it when people hijack my thread,lol..

beocop

If you don't want to take it apart again just keep paying attention to the noise. If it gets different or louder, it's probably need replacement. For me, I didn't want to hear the noise and since I opened it up already, I just replaced it. At that time, I had driven ~5k miles after the noise started.

lit549

Upload some pics,maybe someone will notice something im miss8ng??

lit549

lit549

See how closest edge has worn?only place it rubs is the water pump pully..Could that be my hummimg noise?I cant find ANYTHING wrong..

beocop

Since you already opened it up, just take off the belt and inspect it carefully. It's hard to tell from the pics. I didn't catch the rubbing the first time I opened it. My suggestion is to take the belt off and replace it with a new one so you can eliminate the TB as a cause. After you take off the belt, inspect the other components (pulleys, tensioner, guide plate etc.). If the noise is still there after you put it back, then it's something else.