Squeaking Noise - Help - 986 Forum - The Community for Porsche Boxster & Cayman Owners

sharper410 · 07-12-2025, 10:05 AM

I've got this squeaking noise that I can't figure out so I'm hoping someone may have some thoughts. I assumed this was a belt or pulley problem but they all check out fine. I even took the belt off and ran it for a few seconds and the sound remained. Another thought was the secondary air pump because it is really noticeable from the right side intake vent. I pulled the relay for that and still get the noise, plus it keeps going long after the air pump should stop. The noise first occurred after sitting for a month or so due to non-stop rainy weather. Just looking for other things that might cause this that I can look into. I'm trying to get this 986 cleaned up to try and sell. Here is a link to a video of it. https://youtube.com/shorts/YdrPGtbv5vI?feature=share

maxbottomtime · 07-12-2025, 01:23 PM

You’ve ruled out most of the moving parts by removing the belt (water pump, alternator, etc.).

How about the ventilation fan on that side? Pretty loud on mine when it kicks on. Bearing there?

sharper410 · 07-12-2025, 02:58 PM

Quote:

Originally Posted by maxbottomtime

You’ve ruled out most of the moving parts by removing the belt (water pump, alternator, etc.).

How about the ventilation fan on that side? Pretty loud on mine when it kicks on. Bearing there?

That was a good idea I didnt know about. Unfortunately I pulled the relay for it and still get the noise. Starting to worry this is something internal which would suck as this engine is a pain to get to.

pilot4fn · 07-12-2025, 08:39 PM

Check if all spark plugs are tight (to torque spec).
If one comes a bit loose, the pressure leaks out just a bit and makes thsi kind of noise that changes by rpm - ususlly shows up only as the engine is hot / normal operating temperature.

I had same in mys Boxster few years ago and torqued all plugs - one was just a bit loose -> chirp noice went away.
If you check the plugs, make sure to re-connect the coil wires real well to the point that you can feel the slight 'click' as the wire connector is all the way home (otherwise there will be misfires).

sharper410 · 07-13-2025, 04:13 PM

Quote:

Originally Posted by pilot4fn

Check if all spark plugs are tight (to torque spec).
If one comes a bit loose, the pressure leaks out just a bit and makes thsi kind of noise that changes by rpm - ususlly shows up only as the engine is hot / normal operating temperature.

Thanks! I think that was it. All of mine were loose. I retorqued them and the noise is gone.