Polman

Hi, since my 964 Turbo still is rather new to me, I don’t find my way”around it” like on Carrera 2 and 4…
I have a very annoying noise from the rear. I hear it when I’m sitting in the coupe with the motor running. It comes high up (where the seatbelt and speakers are) from the rear right side like a blurring and gurgling sound. Is there maybe a fuel pump there ??

crg53

I do not know about the turbo, but on my na C2 I get that sound on start-up. It is from the oil being returned to the oil tank, it is normal Porsche sounds.

Boeing 717

Gurgling noise is normal its oil flowing into the tank i think, but its never been loud enough to bother me.

Metal Guru

When it's cold out my power steering pump makes noise for a short time at start-up.

Polman

Hmmm.....this is my sixth Porsche 964 and I haven’t heard this noise before. Its more like something is vibrating and gurgling from this area all the time....hot or cold. With a constant sound and its not pure mechanical. You cant hear it from the outside. What about the fuel pump...isn’t there one located up there? Maybe I can post a sound file…..could be interesting since you all are good detectives

fritz k.

actually the rear fuel pump is locateted there, beneath the air filter housing.

but as the guys wrote, gurgling noise comes from oil return into the tank and it is normal. mine somtimes sounds like a water downfall...

fritz

Metal Guru

You might need to overhaul the thermostat. There's an o-ring that wraps around the piston. When I took mine apart there was a build-up of corrosion around the o-ring.
It would be a good time to replace the oil hoses running to the thermostat. These hoses (especially the long one that runs to the thermostat top) are going or have gone bad by now.

Boeing 717

Yes the fuel pump is right there behind the power steering fluid resevior in the right rear. Mine went bad and was making a constant "wurring" noise.

Polman

Sounds like I have Jerry’s old problem......
When does the pump engage? When I turn the ignition on= no noise
Motor ideling = a constant noise regardless of rpm
I must locate the bastard pump and listen with a stethoscope....

fritz k.

in order to make the pumps run remove relay 61 (luggage compartment) and connect the terminals 30 and 87 at the slot. with ignition "on" you will be able to listen to the pumps.

fritz

Polman

Sounds like you know what your talking about Fritz.....Okay relay schould go out, do I connect 30 and 87 in the empty place with a simple electrical 2 mm2 wire?

fritz k.

yes, 2mm is perfect.

high sophisticated version is to use a long cable with fitting cable plugs and a switch between. it allows to control the pumps while hanging with the ears in the engine compartment...

fritz

Polman

I did the "Fritz" trick today.....and its the pump that makes a constant sound. There must be some bearings inside that gone. Will fit a new one. Thanks for good support!

Boeing 717

Good Deal, Make sure and put alot of rags below it when you disconnect the fuel pump because you will lose about half a coke can of gas out of it.