Strange Noise...with pictures and audio clip

djdrock

djdrock

Experienced Member
Joined
1 June 2005
Messages
948
Location
Happy Little Tree, Indiana
I have never heard this before, but today, I noticed a strange sound. Running the AC, or engaging the clutch makes no difference. The performance of the vehicle is fine. It sounds like it is coming from a pulley on the passenger side engine bay area on the bottom. As I accelerate, it does increase the speed of the noise. Here is a sound clip and some pics of where I think it is coming from during idle. My car is a 91 with 45K miles.

http://www.yourfilehost.com/media.php?cat=audio&file=noise.mp3 Be sure to hit the tiny play button.

Any ideas?

Thanks!
 

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Certainly seems like might be the AC compressor pulley - try loosening up that belt so it slips completely & see if it goes away
Since it's not only on when the compressor clutch is engaged you may be lucky & only need to replace the clutch rather than whole compressor.
 
Hugh said:
Rub a bar of soap on the inside of the serpentine belt and report back.

By the way, is that a non-OEM oil filter?
Click to expand...

No luck...I rubbed soap on it the best I could, but the noise is still there. And yes, it is a non-OEM filter. :wink:
 
djdrock said:
No luck...I rubbed soap on it the best I could, but the noise is still there. And yes, it is a non-OEM filter. :wink:
Click to expand...

Bummer, then perhaps Ken's suggestion is correct.

What brand of filter is that? Most of the aftermarket ones are not nearly as good as OEM. That's one part I don't gamble with.
 
Hugh said:
Bummer, then perhaps Ken's suggestion is correct.

What brand of filter is that? Most of the aftermarket ones are not nearly as good as OEM. That's one part I don't gamble with.
Click to expand...

STP. Not a good idea huh? I will stick with OEM from now on...especially after doing some reading on this just now.

Anyways, I am not very familiar with the technical aspects of the engine/pulleys etc. The picture that I have of the pulley, what is that? It goes to the alternator...
What are some other pulleys that can be making noise at the bottom of the engine?

Thanks again!
 
Here you go .......

attachment.php
 

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djdrock said:
STP. Not a good idea huh? I will stick with OEM from now on...especially after doing some reading on this just now.

What are some other pulleys that can be making noise at the bottom of the engine?

Thanks again!
Click to expand...

Definitely go back to OEM oil filters. There are 2 belts on the outside of the engine. Each connecting to the crankshaft pulley at the bottom with one going to the alternator and the other to the A/C.
 
Actually as I look at the pic I just posted, realize it could be the idler/tensioner pulley for the A/C belt that's squealing. Probably more likely than the clutch.
Same test will determine at least if you're in the right drive. Once belt is loose you can remove the tensioner & check the bearing on it.
 
Excellent information. I will try and loosen the adjusting bolt tomorrow and see. :smile:
 
I just started it this morning, and no noise. I have not driven it yet or made any adjustments as mentioned earlier.
 
After driving the car, the noise came back. I did notice that the adjuster was very loose, but I was not able to tighten it very much, as I do not have the right tools.

I think I will just take it to Acura this week to see what they say.
 
Be sure to loosen the nut on the idler wheel before playing with the adjuster. Turning the adjuster screw with the wheel locked down will strip the screw.
 
I had a similar problem with my 91. I removed the belt for the A/C compressor and found the tensioner pulley (as shown in the diagram) to have a failed bearing. I replaced it and wala, noise gone. Seems to be common. I think it was about $25.

Have you read up on the harmonic balancer dampener coming apart on our engines. Behind the crankshaft pully is some elastomeric material that dampens out vibrations in the engine. Some of the guys here have had those fail. Some have had those fail and it takes out the timing belt cover and usually the timing belt too. You know what happens then.......things get quiet................. and after that.................very expensive. If you are going to have someone check the A/C tensioner pulley, I would pop (150 ft/lbs) the crank pully off and inspect it while you are there. I would bet it would not cost more than another hour of labor. I know it sounds like a lot of expense, but how much is a new engine? I know your car is low miles, but how many years has it been?

DIDO, DIDO, DIDO, on the filter, I know a guy that a filter cost him an engine!!!!! GO OEM ONLY!!!!!!!!!!
 
Great information again...It was at the dealership all day today, and it, of course, did not make the noise. They are going to check it again tomorrow and I will bring up all of your suggestions. Thanks for the tips! :biggrin:

I spoke with the NSX tech regarding oil filters, and though he knows of no failed aftermarket filters in recent years, he said what is another $15 for the assurance. Great points everyone. BTW...I have 2 brand new non-OEM filters for sale now. haha
 
The noise was reproduced, and they said it was the timing belt tensioner making the noise. The timing belt was replaced less than 2 years/15K miles ago by the previous owner, but I have no idea if the tensioner was replaced.

I have scoured the forum, but found very little about the tensioner making noise.

Any input?
 
***UPDATE***

The car should be fixed on Monday. As it turns out, the original owner took the car to someone who was not aware that when you change the timing belt and water pump on a 91, the water pump has a bleeder valve which then requires a different timing belt cover. Honest mistake, but they should have corrected it by getting the proper cover. Also, the A/C idler tensioner pulley is broken on the top and bottom. It needs to new screws (or something). Again, they believe the original shop that did the belt screwed that up too. :mad:
 

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