Strange sound from NA 2.5

[Jacquiles]

I have a 1986 944 NA 2.5 that i noticed was making a strange noise coming from the front of the motor. When I took the top potion of the belt cover, it was easier to hear the sound. Its higher pitched and can be hear especially when I turn the motor off and it slows down. Sounds kinda like a squeaking metallic sound. I just rebuilt the motor less than 1500 miles ago, so it has a new URO parts water pump and camshaft belt idle pulley. All other pulleys are original to my knowledge. Here is a link to a video of it.

[usury]

Giving this a bump. I'm curious myself.

It kinda reminded me of what my ac compressor clutch sounded like when it got hot and failed many many years ago. (Going on really rusty sensory memory here at best.)

Not saying it *is* the AC clutch, but more to consider sources outside the cam belt cover. Bearings on the AC compressor / alternator / PS pump, for instance. Though upon re-reading your post you do say it's more noticable with the top timing cover removed.

Think about the bearings on the timing belt related rollers that might not have been replaced recently.

[michaelmount123]

Take a piece of fuel line or similar tubing. Put one end to your ear and the other near where you think the noise is coming from. Move it around and the source will be obvious when volume of noise increases. Identifying the source will allow an easy fix.

[Jacquiles]

Giving this a bump. I'm curious myself.

It kinda reminded me of what my ac compressor clutch sounded like when it got hot and failed many many years ago. (Going on really rusty sensory memory here at best.)

Not saying it *is* the AC clutch, but more to consider sources outside the cam belt cover. Bearings on the AC compressor / alternator / PS pump, for instance. Though upon re-reading your post you do say it's more noticable with the top timing cover removed.

Think about the bearings on the timing belt related rollers that might not have been replaced recently.

I was able to find the cause of this noise the other day! My neighbor had a stethoscope he let me borrow and I checked all of the pulleys and on the water pump and found the camshaft belt tensioner pulley to be the culprit. It was much louder than the rest and made the rhythmic sound I was looking for. I will replacing it very soon. Im glad this was the cause because I really did not want to replace the water pump lol

[Jacquiles]

Bumped this post to see if i could get some additional input. the sound has not changed in the last 5 months so it hasn’t really gotten worse

[Jacquiles]

Giving this a bump. I'm curious myself.

It kinda reminded me of what my ac compressor clutch sounded like when it got hot and failed many many years ago. (Going on really rusty sensory memory here at best.)

Not saying it *is* the AC clutch, but more to consider sources outside the cam belt cover. Bearings on the AC compressor / alternator / PS pump, for instance. Though upon re-reading your post you do say it's more noticable with the top timing cover removed.

Think about the bearings on the timing belt related rollers that might not have been replaced recently.

I was able to find the cause of this noise the other day! My neighbor had a stethoscope he let me borrow and I checked all of the pulleys and on the water pump and found the camshaft belt tensioner pulley to be the culprit. It was much louder than the rest and made the rhythmic sound I was looking for. I will replacing it very soon. Im glad this was the cause because I really did not want to replace the water pump lol

This did not end up being the cause of the sound like i originally thought

[ItsSunnyD]

Giving this a bump. I'm curious myself.

It kinda reminded me of what my ac compressor clutch sounded like when it got hot and failed many many years ago. (Going on really rusty sensory memory here at best.)

Not saying it *is* the AC clutch, but more to consider sources outside the cam belt cover. Bearings on the AC compressor / alternator / PS pump, for instance. Though upon re-reading your post you do say it's more noticable with the top timing cover removed.

Think about the bearings on the timing belt related rollers that might not have been replaced recently.

I was able to find the cause of this noise the other day! My neighbor had a stethoscope he let me borrow and I checked all of the pulleys and on the water pump and found the camshaft belt tensioner pulley to be the culprit. It was much louder than the rest and made the rhythmic sound I was looking for. I will replacing it very soon. Im glad this was the cause because I really did not want to replace the water pump lol

This did not end up being the cause of the sound like i originally thought

Try removing both the balance and accessory belt, if the noise goes away when running only on the timing belt you could narrow the field of play.

Sounds almost like a bad bearing on a pully.

[Jacquiles]

Update: I fixed this a while ago, but it was the water pump. I replaced the URO parts pump with a GEBA water pump. When I took the URO parts one off I could feel a lot of play in the pulley. And it was brand new

I should have bought the more expensive GEBA water pump from the start

[Tom]

Update: I fixed this a while ago, but it was the water pump. I replaced the URO parts pump with a GEBA water pump. When I took the URO parts one off I could feel a lot of play in the pulley. And it was brand new

I should have bought the more expensive GEBA water pump from the start

Sadly, URO has a pretty well-earned reputation for making substandard parts. Every now and then they have something that works and is a true bargain, but stories like this are all over the internet with various URO parts.