Not a good day for my 986S 2001. Smoke and engine dead

[tomc88]

my mechanic is coming tomorrow. Will let you know what he finds...

"P0304 fault code is a 'generic' misfire code for number 4 cylinder and I would be surprised if that is the only code as a misfire on one cylinder would not normally stop the engine running.

We know of a few instances on our customers' cars where the engine oil separator, (internet acronym AOS), has failed and allowed engine oil to be drawn into the induction system. This can be the cause of the smoke emission, although the one instance on a Boxster 2.5, did cause subsequent total engine failure! (It cracked the cylinder, but the 3.2 and 2.7 engines have stronger cylinders). There are though other possible causes.

The best course of action is your suggestion of us coming to you to read all fault codes, and depending upon the results, maybe gaining access to the engine and attempting to rotate it manually. A possible further check could be to disconnect the pipe between the oil separator and induction manifold to check for excessive oil."

[utkayaker]

And it could be that the spark plug tube on 4 lost its seal (there are two O-rings) and it blew oil onto the spark plug - shorting it out and then vaporized the oil in smoke.

You didn't say if the smoke came from the exhaust pipe or the side of the engine. Some research I have read indicates many AOS failures have symptoms of excessive smoke coming through the exhausts (but the AOS could also be leaking on top of the engine (doesn't appear to be as common though).

If the spark plug tubes are leaking you will see oil more from the side (or both sides) and smoke coming from where that drips on the catalytic converters and exhaust system.

I would check out tube and plug on the 4th cylinder first.

[WhipE350]

Oh lord, gloom and doom. Be positive this might only be an AOS. I replaced my IMS on a 2000 'S' (waste of time it was double row...though very pleasurable project), changed my water pump (more waste of time the one in my car was like new after 57k miles), and replaced my AOS though I have no idea what condition it was in, can't see inside it . Ya would think the cars are piling up at dealers falling a part. My buddies at both dealers here say they are great little cars and yes they have commented that water pumps do wear out, but so do a lot of older cars.

Keep us posted OP, we hope the best for your car. Fix it and continue to love it.

[tomc88]

update;
so porsche mechanic came over.
Confirmed P0304 only fault code (good news).
He's looked at AOS - and yes, that has failed.
He can manually turn the engine (good news).

He needs to get it to the work shop to see if there is any unseen problems,
but so far his feeling is it is fixable, and almost certainly not a write off!

But I won't get too excited yet. It will get towed in this week and we will see what happens next

He reckons it's probably the original AOS - and he's surprised it's lasted so long (115K miles). naturally I'd have had this changed if I was aware of the problem before!

Seems like we should get a sticker made to stick on the side of the car for noobs, listing the many many things a porsche can potentially do to destroy itself

[recycledsixtie]

Originally Posted by tomc88

update;


Seems like we should get a sticker made to stick on the side of the car for noobs, listing the many many things a porsche can potentially do to destroy itself

Good one Tom. I believe it was Jack Raby(of engine rebuild fame) that said there are something like 21 ways in which a Boxster engine can fail. I wonder how many folks would buy a Boxster if they read all the threads - particularly the one on this forum "thinking of buying a Boxster". For myself I would have bought one anyway because I like the design and brand. Fortunately I bought one with 30k miles - a 2001 Box base and have had no issues. If it blew up tomorrow I would be installing another engine or getting an older Cayman. I fit in the category of "my wife does not understand me" LOL!

[tomc88]

yes, there should be a warning stick.

The problem is we only hear about them when they go wrong. the mechanic was telling me of plenty of examples of low mileage 986/996 with engine failures.

And it makes me thing 'do I really want this potential grief'?

But I think I might run this old 2001 to the ground, then if one day I can afford a caymen/boxster 2009, or a 911 turbo (not likely!) with a 'better engine' then I'll make the switch.

[woodsman]

I'm holding my breath while I wait for the final news Tom- please hurry! And while I absolutely love Porsche's, this will certainly be the last one I own with an M96 engine in it! Everyone's pulling for ya'!

[tomc88]

well it's good news.
other than new AOS and spark plugs all is well.

Not sure if I was panicking over nothing. Must admit my mechanic is a real pessimist

picking her up tomorrow

[pothole]

Originally Posted by tomc88

Not sure if I was panicking over nothing. Must admit my mechanic is a real pessimist

Definitely not.

It did sound like an AOS failure, but you can't be sure. And even an AOS failure can have nasty consequences if you are unlucky!

Super news that it was just the AOS in the end.

[tomc88]

well hopefully this is one common fault now hopefully that won't come up again now there's a new part in there

[The Radium King]

if you look at the part number for the aos there's been multiple iterations of the same part (I think they got up to version 4 before they changed to the 9x7 motors); I don't think the latest, improved version 4 aos fails nearly as much as the one that originally came with your car (probably version 2).

[ganseg]

When i changed mine recently, the one I removed was an .04. How long has that been out?

Since I changed it, I have not had my periodic smoke at startup nor my variable idle. My guess it was only in there 20k, so I do still think they can be shortlived. Maybe this car was overfilled with oil.

[woodsman]

happy for ya Tom!

[southernstar]

Yes, good news indeed! As to the warning sticker idea - there are tons of engines from various manufacturers that have various modes of failure. IMO, for engines that are typically used fairly hard and are now quite long in the tooth, the single-row IMS bearing seems to be the only truly bad piece of engineering and the only potential cause of total engine failure that occurs at a relatively high frequency. Fortunately, it is capable of pre-emptive repairs for those who are not prepared to accept that risk.

Brad

[tomc88]

just collected!

They said that all is very good. will get a little smoke on start up for a while whilst last residual oil burnt up, but all emissions are good, and no damage any where.
They've had far worse before.
They think because my rev's were low when the event happened.

new AOS, new plugs since old were non-spec and fouled, throttle cleaned out.
Apparently I have a sports exhaust manifold, so that made more work to remove the plugs.