henkinc

On cold startup, for about the time I imagine the SAI is working, I hear a fiant whine from perhaps the driver side, rear of the engine. Almost like an alternator bearing if it were in the center (which it might be). This started to be evident after my 60k mile tune up (at 55k) in which the check valve for the SAI was replaced. Check valve had been badly blocked before.
Question - does a properly wokring SAI pump make this noise, assuming the lh side SAI ports are blocked (which mine are, at least for cyl 2 - I get the dreaded 0410 code)?
Thanks.
Charlie
97 triple black cab, M030

BobbyT

Easy enough to check--just pull the fuse or relay for the SAI pump, located in the engine bay fuse/relay box on the LH side.

AOW162435

Charlie,
The pump is located just right of center, at the rear of the engine. A check valve replacement should not affect the actual electric pump.

It's all a distant memory for me though - my SAI pump now lives in Florida...


Andreas

Stealth 993

If you have a scanner, you might be able to turn the pump on. With the Derametric scanner, you can turn on the pump any time. I did this to check my flow with the engine off, it really pushes some air out the mufflers!

TAI2

You might also be hearing the new belts if they were changed. They do whine for a while.

AOW162435

Hmmm. If that's the case, I should re-install mine and wire it to run at all times. I think it could act like a low-pressure turbo.

Hmmm.


Andreas

Stealth 993

LOL! Very low pressure, it just spits out the exhaust, not in the intake.....

But it might help exhaust scavenging!!

AOW162435

Exactly. Whatever.





Andreas