Please help me identify this odd noise from the engine (w/video)

black_falcon · black_falcon's Garage

My 86 944 n/a is making a whistling/gasping for air sound from the front of the motor, maybe behind the timing belt cover. I first noticed it around 2004, but it's been getting louder over the years and now sounds like something is about to break. It shows up after the car has been warmed up and running for 10-20 minutes.

I've had two majors done, including a belt job a few weeks ago, so I know it isn't a part such as a roller/belt/idler, etc.

Today I noticed it was abnormally loud, so I shot a video, did a bit more driving, and then came home and noticed a grinding sound was now present too (it can be heard slightly in the first video too), so I shot a second video.

Please tell me what you think..

mytrplseven · mytrplseven's Garage

When did you last change the water pump? Is this an auto or manual tranny? If it was me, I'd go to Harbor Freight and buy a stethiscope and start snooping around the engine to see where the noise is coming from. When you had the belts done did you also do the rollers and the tensioner? It sounds like something along those lines is really spinning on bad bearings. Any oil leaks of note under the engine? If so, where are they coming from (front, real, left or right side.)

JAXTURBO · JAXTURBO's Garage

+1 on the waterpump. That was my first guess. I agree with Mytrplseven get a stethiscope and start snooping around every rotating part up front. Alternator, P/S pump, distributor, waterpump, and ultimately the timing belt cover.

black_falcon · black_falcon's Garage

Hey Guys- IIRC (I'm 99% sure I do) it started making this noise before they did the water pump in 2004. I skipped the pump when I did the belts this year since it only has about 15-20k on it. Belts, rollers, idlers, have all been done twice while this sound existed so I don't think those are the culprit.

No oil leaks that we found. The alternator and PS pump are about the only things I haven't touched on the car since I bought it in 2003.

bell · bell's Garage

pop of the ps belt and the alt/ac belt and see if the noise is still there......

mytrplseven · mytrplseven's Garage

I tried to discern from listening to the sound what you were referring to but I think my laptop speakers weren't up to it. I heard a lot of noise and yet nothing definitive. I'm even wondering if it might be a loose engine heat shield. There's one under the exhaust manifold next to the oil pan that might be vibrating, but again, I can't make out the noise. Does the noise change when you: turn the A/C on? When you turn the steering wheel full left and right? Removing the A/C belt and P/S belt is a quick and easy way to eliminate a couple of major systems. After that, I'd pull the front cover off the belts area and see if the noise is louder and more apparent than before. Whatever it is, a repair/replacment of the failed unit is definitely down the line.

mytrplseven · mytrplseven's Garage

More thoughts: Are you SURE it's from the front? If it is, might be forward cam bearing, if not, since you didn't say you're car is a manual vs automatic, that a pilot bearing or throwout bearing might be worthy of consideration. Anyway, since we're all spit-balling here, after you pull the lower belts off the a/c and p/s let us know what you found. If you don't want to spend the money on a stethescope, we used to get a long screwdriver and put the pointy end on the suspected area and the handle end in our ear. It actually does work.