Diagnosing a Noise

[djnolan]

Folks,

The good news, I have obtained a 3rd 944. It is a red 86 N/A, 120k miles, with Fuchs and sport seats. The body and interior is immaculate, not even the slightest of cracks in the dash.

However I still have deep affection for my 85.5 automatic that has carried me to work for five years or better, at least when she has been up to it. To me, an automatic is somewhat better in rush hour traffic. However she is getting on in the miles (178k) and makes some troubling noises when cold.

The problem is a tapping or knocking noise during warm up that goes away once fully warmed up. The possible causes (from what I have read) could be engine mount, torque tube or flex damper related, engine related such as rod bearing, wrist pin, or lifter, and probably a few other things I haven't even thought of.

I would love to drop it off at my FLPRF (Friendly Local Porsche Repair Facility) for expert diagnosis, but I fear they will see me coming from 100 miles away and will prescribe repairs that don't make economic sense.

How can I get a proper diagnosis of this noise so I can make the right decision on what this car is worth, whether I should keep it, etc?

Thanks for your time.

[tamathumper]

Do you have a mechanic's stethoscope to locate where the noise is coming from?

[Slam]

Can you post a vid on youtube?

[rhett]

Here is a suggestion..I also had a strange knocking noise that exhibited the same symptoms. Check the timing belt as it could be slightly loose (especially on the drop down to the crank sprocket - other side to the water pump). This can vibrate and make all sorts of noises that seem to be amplified by the plastic covers, etc. The sound would tap, tap away until everything warmed up (the block expanded and took up some of the slack). If it goes away when the engine is warm it probably isn't the torque tube bearings or the engine mounts..it has to be something that is effected by expansion - have a look in the belt area.