Is it time to get Porsche wrench help with my tap/knock problem?????
 

Hey guys, I have reached a point where I think it is time to take her to a professional. From a porsche novice with empty pockets, I think I have done all I can do to figure out my engine tapping/knocking problem.

It all started when I located and sealed a massive vacuum lead around my pop-off valve. This was related to a high idle problem, that immediately went away after sealing the pop-off valve. I was now able to get the idle to 950 rpm.

Since then, a new problem reared it ugly head- I now have this awful tapping that is most pronounced at #4 intake runner detected using the old long screwdriver between the runner and my ear method.

Here are a few more symptoms I have noted:

**When I first bought the car and changed the oil I noticed small metal particles attached to the magnetic drain plug. I have noticed none since.

**Upon initial start, the engine oscillates about 500 rpms for about 30 seconds, then settles in at 950 rpms.

**On warm days 75degrees or so, the rpms will sometimes increase to 1800 until the engine is shut down and restarted.

**Under load, I can hear what sounds like a rattle coming from the engine compartment.

**I drained the oil through a white t-shirt and did notice a few silver flecks of what appear to be metal (non-ferrous). There were only a few and there was no metal detected on the magnetic drain plug. Shining a bright light into the oil it appears as pearlescent.

**The oil temp seems good and pressure is strong between 4 and 5 bars at 3k rpms.

**I checked and adjusted all valves which did not effect the tap/knock problem. I also disconnected the plug on #4 which also did not effect the problem.

**There are no oil leaks or other outward symptoms that I have noticed.

Aside from these things, the car runs reasonably well.

Is there anything else I can do before I place myself at the mercy of the mechanic?

If it were my car, I would take it to the Porsche technician at this point.

What year/type of 911 is this? I assume a 911SC.

I am not sure how to help but here is a bump, anyway.

Havign a partnership with a decent wrench is a good thing. You do the things you can and he helps you when you get in over your head.

She is an 81' SC with 85K miles. I have had it about a year.

Thanks Harry. I am beginning to come to the same conclusion. My only problem is the decent shops are about 40 miles away. I have been trying to find one closer to where I live in Waldorf, MD- any suggestions?

Sorry but I am on the other coast so I cannot be much help.

Look in the Regional forums (http://forums.pelicanparts.com/middle-atlantic-us-dc-de-md-pa-va-wv/) for some recommendations or check your nearby PCA Chapter (www.pca.org).

I'll check them out!