Morten Skaar

Hi all, I have gotten a strange sound in the engine. It shows up at 1000rpm and goes away when the rpm goes higher. At first I thought it was the assisted steering pump. Seems like the whole intake is shaking when this is going on..

Anyone have a good suggestion where to start looking?

rgds

Morten

Morten Skaar

95 993 Carrera with sport muffler, KN filter and chip.

pp000830

Power steering low on fluid?

Morten Skaar

That was my first thougt, but fluid level is as good as it gets. Would the power steering belt cause this sound? If it does it has a strange way to route the sound. Alternator perhaps?

pp000830

Rubber debris in fan housing moving around?
Fuel pump sound due to pump housing vibrating against sheet metal. Air injection system hose leak. Makes noise until pump shuts down.

pp000830

It is a toothed belt however if it is jumping teath I would think other symptoms would be present.

mpruden

I'd get under the car and take a look at the steering belt. I've never heard one fail, but since that belt is driven off the camshaft, I would want to verify it's not causing excessive vibration on such a critical system of the car.

nine9six

Sounds possibly like 1000 rpm is the vibrational sweet spot that some piece of debris may be dancing to. Have you thoroughly checked internal panels along with your engine bay, down into the nether regions?

Morten Skaar

Will search the engine bay thoroughly next week for debris and loose panels etc, If nothing found i will start the elimination process! Thanks for all the input so far and have a great 993 weekend!

kjr914

Your video makes it sound like.....an engine... Damn near impossible to get a video to actually play back what you are hearing unfortunately.

Hit up harbor freight for a mechanics stethoscope (whopping $4 or so). Just don't bang the end around while moving it or your ear drums will not like you. Or a long handled screwdriver with the metal end on the engine and the plastic held against your ear (other way around doesn't work well....)

nine9six

From personal experience, Keith? Kidding of course! Hope your summer's going well.

Holytin

For what it's worth - cooling fan bearing...?