phlporsche

I tried a search but have not had luck in identifying a part that is making an unusual noise. Here is a picture (not my engine bay, found in a search) with an arrow pointing at the part. I am guessing alternator, anyone know for sure? The issue I am hearing is a pinging metal on metal noise when starting cold.

Video of the sound this morning:

frisbee91

Secondary air injection pump. (SAI)

https://rennlist.com/forums/996-foru...epair-diy.html

narkose

SAI pump. There is a DIY for servicing it at Renntech as stated above but that is described more for a whining sound. Not sure about the pinging you describe

phlporsche

I love this site. 10 minutes and I have my answer. Thanks frisbee and narkose.

Imo000

It's a snowcone maker!

Barn996

Known for making a racket when failing, usually just at startup. Record the sound and share it on Rennlist.

5CHN3LL

KrazyK also posted his DIY repair here in the 996 forum:
https://rennlist.com/forums/996-foru...epair-diy.html

Since the impellers in the pump are metal, the metallic pinging might be some kind of debris inside the pump bouncing around when the SAI pump is energized.

I imagine you'd throw some emissions-related diagnostic trouble codes if you just unplugged the SAI pump until you have a chance to repair or replace it - but that might be better than doing any further damage to the pump if something really has come loose or been introduced. Anyone else able to opine on what codes you'll throw with the SAI unplugged?

phlporsche

I thought it was potentially the flux capacitor and it needed more plutonium.

phlporsche

Here is a video of the sound. Does this change the diagnosis for anyone?

Kalashnikov

It is a SAI pump. To eliminate it from the equation disconnect the electrical connector going to the pump. Start up the car when cold, if noise is gone...you got your proof.

Ahsai

If the noise goes away in 2 min or so into a cold start, that's another indication the noise is from the SAI pump as it turns on only for the first 2 min during a cold start.

phlporsche

I will test in the morning but that is exactly the case. Gone once warm. I hear it in my garage every morning.

Thanks all.

Ahsai

I predict a CEL and a bunch of P04xx codes, which should all clear themselves after a few drive cycles with the pump plugged back in.