Squeaking noise during cold idle

m96ag · Post by **m96ag** » 08 Jul 2016, 07:30

Hi guys. I have an intermittent squeaking noise that occurs when the engine is cold. It sounds like it's coming from the passenger side and I have replaced several components either to try to fix the noise or for unrelated reasons. I have replaced the serpentine belt twice. The serpentine belt tensioner, the alternator for unrelated reasons, the timing belt, idler pulley and tensioner along with the water pump for unrelated reasons. I tried spinning all the pulleys with the serpentine belt off and they all feel smooth and appear to spin straight when the belt is on. Could it be the harmonic balancer?

Matt

kippster41493 · Post by **kippster41493** » 08 Jul 2016, 13:47

Sounds like a bearing of some sort, if you spin the pulley's with the belt off there is no tension on it. Adding pressure can cause old, worn out bearings to slack a little bit. If you have the chance have the hood open and listen as best you can to see if you can narrow it down. Does it go away quickly or under acceleration?

101 · Post by **101** » 08 Jul 2016, 14:44

^^ agree with the above.

Two ideas for you:

1) Buy a cheap mechanic's stehescope and see if you can use that to narrow down the area where the noise is coming from.
2) Remove the serpentine belt and start the engine. You can safely run the engine for a bit as the water pump is rotated with the timing belt. If the noise stops, at least you know that the timing belt side of the equation is OK.

The harmonic balancer is directly attached to the crankshaft and does not have any bearings itself.

Post by **MadeInJapan** » 08 Jul 2016, 16:54

If none of those are the squeaky part, turn off the fan to the AC/Heat to make sure it's not the blower motor. From inside the cabin, it could sound like it's coming from the engine bay.

m96ag · Post by **m96ag** » 08 Jul 2016, 16:59

MadeInJapan wrote:If none of those are the squeaky part, turn off the fan to the AC/Heat to make sure it's not the blower motor. From inside the cabin, it could sound like it's coming from the engine bay.

I tried it with the blower and radio off. I'm going to try running the car without the serpentine belt.

Post by **abscate** » 08 Jul 2016, 22:04

Get to the bottom of this before you drive this car. You can easily pull a 3000 USd job if TB fails

m96ag · Post by **m96ag** » 08 Jul 2016, 22:34

abscate wrote:Get to the bottom of this before you drive this car. You can easily pull a 3000 USd job if TB fails

The TB was replaced along with the water pump, tensioner and idler pulley

Sommerfeldt · Post by **Sommerfeldt** » 09 Jul 2016, 05:37

On my 850, it was the tensioner for the serpentine belt. Replaced that, and discovered that about 80% of the squeak was gone - the rest is apparently the alternator, which I'm keeping at bay with some bi-weekly sprays of a little lube.

- S

m96ag · Post by **m96ag** » 09 Jul 2016, 05:56

Sommerfeldt wrote:On my 850, it was the tensioner for the serpentine belt. Replaced that, and discovered that about 80% of the squeak was gone - the rest is apparently the alternator, which I'm keeping at bay with some bi-weekly sprays of a little lube.

- S

Both of those have been replaced.

Sommerfeldt · Post by **Sommerfeldt** » 09 Jul 2016, 06:31

m96ag wrote:Both of those have been replaced.

That doesn't necessarily exclude them, though.

101's suggestion is the absolute best - either buy a mech's stethoscope, or use a length of vacuum tubing as one, and track down where it's squeaking. There are so many moving parts there that its's really the only option.

- S