TMc993

No, it's not a chainsaw joke...

'97 C2 Coupe - 50K+ miles

I have a new noise coming from the passenger side foot well:

The noise:

1. Is present only when the engine is running, but is consistently present when the engine is running.
2. Is absent when the engine is off regardless of the position of the ignition key (OFF, AUX, etc.).
3. Sounds a lot like the SAI pump, but isn't. The SAI pump runs and shuts off properly on cold start.
3. Can be heard only if one is sitting in the car and is more audible when I lean over into the passenger foot well.
4. Does not change in frequency or intensity if the engine runs faster or slower.

Ideas?

Thanks,
Terry

TheOtherEric

Oooh a riddle. I love riddles!

Hmmm how about the ventilation blower? You can access it via the front trunk. There's probably a fuse you can pull to test the theory.

That's all I got.

davesnothere

Fuel pump?

Barney1

Chip monk chewing on the wires ??

Just kidding

Arena993

I think the answer may be in the 7 page "How do you close your hood" thread.

Mike

TheOtherEric

Good one! Super easy to test the theory. Just pull the DME, jump the 2 correct contacts in order to force it on, then listen for the noise.

To jump those terminals, see the shop manual. It's shows the pic of jumping the terminals several times in the diagnostics section. You should ideally use a fuse too. So stop at radio shack and just buy a fuse holder, which will have a couple inches of wire sticking out of it. Then just crimp on a couple spade connectors. Easy!

TheOtherEric

Here's the pic from the shop manual:

shamrock

Have you stood in front of the car with the hood open and the engine running? It not something I'd normally do but the other day I was there , and was really surprised at how loud the vent blower fan was. It might be worth doing to see if it's the same ???
(Sorry if this is all a bit obvious .. I'm only a beginner!!!)

TMc993

I forgot to mention that the ventilator fan is off, so it's not that; and since I've did the LPMM I can't hear anything outside the car other than exhaust noise.

My original theory was the fuel pump, but I never pose theory with questions because it influences responses.

Noisy fuel pumps make me queasy...Hasn't been noisy for 50K miles, then suddenly it's loud...Can failure be far behind?

Thanks guys...I put a 30-87b jumper on it and see what I get.

Regards,
Terry

kjr914

I can hear something in my car occasionally (sitting idling), which I've always thought was the oil lines running up to the front wheel well oil cooler. Sounds like running water to me... I can hear it from the driver's seat and it seems to be on the passenger side somewhere down low.

KASH '95 993

I have noticed a similar sound coming from the passenger side also. Sounds very similar to a humming transformer, initially I thought it was the radio but it did no go away when I turned it off.

BTW, what does LPMM stands for?

timothymoffat

+2 for the fuel pump.

John Velasco

I think it may be the motor for the auto temp control. it will run for a while after the key is removed.

TMc993

Kash -
LPMM here - https://rennlist.com/forums/showthre...highlight=LPMM

John,
It's not the temp control...I'm familiar with that and it's a separate noise.

Thanks,
Terry

cabrio993

Terry,

Did you remove the empty blueberry wine bottles from the passenger side foot well yet?