Cough, sneeze and fart

[davedeck]

My indie has officially given up on my car. A little background- it was running great. I drove it 1200 miles to the Parade in June without a hitch. It ran fine for 3 months afterwards. I went to start it one afternoon and it would not hold an idle, coughing, backfiring and every other kind of noise. Check the codes and said misfire on 4,5 & 6. Tried to start again and it ran fine. A couple of weeks later it did the same thing only this time misfire on 1,2 & 3. Had it towed in and replaced MAF, plugs and O2's. Then my mechanic discovered clogged cats that had actually exploded inside. Replaced the cats and the MAF again. No luck. Checked intake for leaks all good. Anybody have thoughts on what this could be?

[jdraupp]

Your indie gave up? Hate to say it, but time to find a new mechanic or bite the bullet and take it to a dealer. If you gave up on it then ok, I'd say we could help...but you took it to a mechanic and he threw in the towel? Yikes. Sorry for your luck.

[Jamesp]

Need the year and the model. I had misfire codes on one side and sketchy idle after the electrical connector for the variocam popped off after I rebuilt the engine and failed to properly connect it in my 03S.

[davedeck]

1998 Base. I don't believe I have Vario-cam or at least I haven't seen it mentioned.

[RandallNeighbour]

You do indeed have a variocam...

[jdraupp]

Originally Posted by davedeck

1998 Base. I don't believe I have Vario-cam or at least I haven't seen it mentioned.

Yeah, you got it, that's how the Porsche magic happens.

[davedeck]

Learn something new every day. I thought it was added to the 2.7 engine. I will advise mechanic. Thanks people.

[thstone]

Originally Posted by davedeck

I will advise mechanic.

Time for a new mechanic. He should know this.

[jdraupp]

Originally Posted by thstone

Time for a new mechanic. He should know this.

Holy crap, if your mechanic doesn't already know this you need to get your car out of there as fast as humanly possible. The guys who work on Porsches know Porsches. Not all "euro" car shops are created equal.

[davedeck]

A hole in the bottom of the intake plenum was the issue. I haven't a clue what caused it but they covered it and everything smoothed out.

[jcslocum]

there are a few things that can be done quickly. The3 Crank Position Sensor is about $110 and 45 mins to install. This controls the ECU for when to fire. There is no diagnosis via computer for the CPS either.

The next area to look at is the fuel pump and the delivery of fuel.

[jdraupp]

Originally Posted by davedeck

A hole in the bottom of the intake plenum was the issue. I haven't a clue what caused it but they covered it and everything smoothed out.

Glad to see they figured it out, but did they not test for vacuum leaks during initial testing? I feel like that hole should have been fairly easy to spot. Irregular idle is often caused by vacuum issues. Again, I'm just wondering if you should reevaluate your relationship with said shop. Looking out for you and your car in saying so.