2005 Cayenne Base Motor Dead? (Update 1 - RIP) ( Update 2 - Revived)
 

I have a bad feeling our trusty P!G might have given up the ghost yesterday. We've owned it for 7 years and 70,000 miles with regular maintenance and any need work preformed by a local import shop (No close Porsche dealer).

Was on my way home from a short errand when the engine started to hesitate and lose power. Accelerating slightly eased the hesitation but there was still an obvious shudder/shaking from the engine. Luckily I was about 50 feet from home and was able to turn into our drive and coast to a stop with the engine sputtering and lugging to a stop. I turned the ignition off, did a quick under the car check for the loss of any bodily fluids - none seen. Under the hood fine too. I tried to start her one more time and it was the roughest idle I'd ever heard and felt. It ran for maybe 5 seconds and died - with notable white exhaust that reeked of unburned gas. We've had no issues with the engine the whole time we've had it. No noises, no knock, no ticks, no hesitation, nada. No warning lights on the dash before this episode either. Hooked up my code reader and i'ts not spitting anything out :(

I've had it towed to my local mechanic who will take a look at it beginning of the week. I guess I've come here to share my tale of woe and was wondering if there would be any speculation as to what could cause such a 'catastrophic' (possible) ending to our P!G. The cylinder scoring issues seem to give some sort of warning, a blown head gasket shouldn't be that dramatic either right?

Thanks for any ideas or advice. - Hopefully this doesn't turn into a what should I buy now thread by next week....

Did you check the oil? If so, what did it look like?

Did you check the coolant? Again, how did it look?

Big clouds of white smoke tend to indicate head gasket issues. Those would likely show up as 'chocolate mousse' oil and oil in the coolant.

However, without good info ('loss of power' and 'shaking/shuddering' doesn't count) it's hard to say.

The 'funny' thing is that sometimes (not always), the 'end of life' symptoms are subtle and appear minor (ticking to indicate scoring for example) while 'horrific and severe' symptoms can be minor and easily addressed.
No clue what you are dealing with.
Good luck.

Thanks for the reply. I did check the oil and didn't notice anything out of the ordinary - level was fine, color seemed fine, didn't look foamy or thickened - but I also didn't do a deep dive, I think I was in panic "Oh ****" mode. I didn't check the coolant though :(

I know I don't have a ton of information and don't really expect any true diagnosis from the information I provided, just sharing my misery. Just on the off chance someone would go "hey that happened to me!"

Thanks again for the reply and asking for more info!

Oil pressure > coolant pressure. Open the tank and have a look. Oil will always go to the water.

You said base so I assume you meant its a v6. Timing issues would be my next guess.

Since it's sitting at the repair shop I won't be able to check, but future lesson learned.

Timing was one of my suspicions, guess that could range from distributor problem to timing chain, right?

No idea of its connected but I've been fighting water in the driver side carpet since winter. I've had to solder the ignition wiring and a couple other connections because of corrosion. Could the known drain plug problem create a timing issue? I haven't had the chance to pull the wheel well cover yet to check if the drain is full. That was actually on the schedule for this weekend

Thanks!

We need to know what that cloud smelled like. If a head gasket, it will smell like coolant. If a head gasket, parking the car when hot with the cooling system at full pressure will force coolant into the cylinders and then if you get a cloud on startup that smells like coolant, that's pretty much a definite for head gasket.

The smell of unburned fuel could just be a plug not firing due to a bad plug, bad coil, or a sensor like cam or crank position.

Further investigation is definitely required.

It definitely smelled of fuel not coolant. Smelled like a flooded engine after it died.

No history of smoke on startup. Coolant and oil levels have been steady.

Thanks again for the insights

I'll keep the thread updated when I hear back from the mechanic.

On a good note at least it's giving me a reason to drive our Panamera GTS regularly without guilt 😉

Sounds like coils to me.

No, seriously: My '05 VR6 had all those symptoms. It was a bad coil. I replaced all six for a couple hundred and everything has been fine since. This is the most DIY of DIY jobs. I doubt it took me 15 minutes to replace all six.

OP has no CEL and no codes. Wouldn't coil failure(s) give a CEL and misfire codes?

Oddly enough coil failures don't always throw codes.

Sounds like coils to me too.. and it would be a wise move to replace the plugs at the same time. We had a BMW 525i '03 that loved to foul multiple plugs if one coil starter misfiring. The fix was always replace the coils showing misfires and all the plugs.

That was my experience as well: no CEL.

Right now a coil issue seems to be my best case scenario. Hopefully should get some info tomorrow or Tuesday from the mechanic.

Thanks for all the info.

These VR6 motors seem to be very rugged in this application, In the 10 years I've been on this forum, I can't remember any VR6 motor having significant problems (although I've heard of them having issues in VW platforms).

I wasn't even kidding about this being a DIY. Once you pull off the plastic engine cover, you pop each coil out (a flat-bladed screwdriver helps as a lever), pull the electrical connector, push in the new coil, snap the connector back on, and you're done. It will take you longer to unbox and take the new coils out of the bag that it will to put them into the truck. If your mechanic charges you more than an hour of labor for the job, he's ripping you off.

Here's the procedure. He talks a bit, so you can jump to 1:50 to watch him pull and replace a coil.

Holy cow that's easy, thanks for the video link Shawn.