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Not a good day for my 986S 2001. Smoke and engine dead
not a good day. on the motorway, cruising, maybe 80MPH, 3500rpm or so.
big cloud of smoke out the rear (the cayenne behind me then backed off quick and changed lane! sensing trouble. expecting me to throw engine parts in my wake). sensing doom, I slowed a little and started to pull over. then some more puffs of smoke, pulled over, then engine shut down and the engine light came on, then all lights. of course not risking a restart. First thing you start thinking is IMS!! no leaks at all. no clunks or grinding. The whole episode was quite and smooth. Got a tow home. I have a cheap wifi OBDII reader. hooked up to iPhone, only code its reading is P0304 nothing else, but it was cheap and I can't be certain it's telling me everything. Nothing I can do, will have to get the garage to sort it out, but wonder if you know that code, the smoke etc and might have a clue!! smoke colour; wasn't white, wasn't blue. just smoke! not sure, was concentrating on the road. Car (was) only worth £5K, Will be interesting to hear whether it's written off! Hoping it's a 'cheap' fix. The annoying thing is, if I get it fix, can I get my faith back in this individually car, or indeed the mark! My first every major break down in 26 years so I guess it;s a shocker. For you UK guys, make sure you join the RAC! I am glad I did, and will never leave home without it |
Sorry to hear of your misfortune. PO304 is misfire from cyl.# 4
Contact Autofarm &/or Hartech they are the best in the UK for these engines. |
Based on my scanty description you think it's serious?
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P0304 code means: cylinder 4 misfire damaging to the catalytic converter. My quick search suggests that a bad coil pack can cause trigger this code. Not sure how that would cause / explain smoke. If you want to run a quick check for internal damage, inspect the oil filter for metal debris. Hopefully you don't see any and have reason to hope.
PS: a failed air oil separator can create huge smokescreen behind your car. |
it's beyond my abilities to fix! Luckily there's a porsche specialist garage I use a few miles away. I'll need to get them to tow it in and check it out
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Cylinder 4 hydro locks earlier than all others during an AOS failure. This is due to intake manifold characteristics.
I bet you have an AOS failure. Collateral damage TBD. |
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Nothing to worry other than having to change your AOS unit ($300 job sadly)
Friend here had the same thing happening to his 986 of the freeway. HUGE puff of smoke, car/engine stalled because of all the oil found its way in the cylinders at once and that doesn't burn too well. Dash lights went on (solid CEL), we all panic, etc etc etc.... same as yours. If the engine simply stalled slowly and you didn't heard any damage-style noise then the engine is just fine mate. Hydro-lock, whatever that means, would have "locked" the engine and you would have heard it badly I believe. Possibly wheel locks and all as well...... Wouldn't worry too much. Also, because some oil found its way in the exhaust system, your O2 sensors will be next ;) Cheap cheap fix |
Hydro Lock doesn't actually seize the engine in the majority of scenarios that occur at speed.
The cylinder does not have to become completely filled with oil for the top ring to break, which is what generally happens with #4, or the cylinder will crack/ D chunk. There's also the possibility that you just fouled the #4 spark plug, because that cylinder sees the most oil and sees it faster than the other cylinders. Quote:
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Love my (wife's) Land Rover... brutal and resistant engineering style MY DD is a Ferrari :troll: |
interesting to find out about the top ring flipping because of 'oil'. Not funny
You gotta love these cars |
I did spot the oil was down to the minimum mark on the dip stick.
Had oil change only a couple of months back. So I guess that missing oil blew out of my exhaust Yesterday! Will I lose faith in this car now? Is it 'just one of those things' that can happen to any car? Surely in general they are as reliable as Any other cat. My confidence is shaken but hopefully it will be restored |
It's a 12 year old, high-performance car.
Obviously there are MUCH WORSE things that could have happened.. and they didn't (yet, knock on wood). Sounds like your AOS went out, and after replacing it you should be good for hopefully quite a while. Good luck friend. |
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They are in fact, "delicate cars", Porsche. That's how I should have described it at first place. You have to know them in & out very well, listen to them, plug them regularly, carry out overkill maintenance (e.g. oil@5,000km, MAF@20,000km, O2@40,000km, coil pack&plugs@60,000km) and chances are they work flawlessly - s p o t - o n as per design. However, forget about 1 (one) of those maintenance item and you may see things going completely wrong very very fast.... that's the only bad thing about these pcars, or should we say "precision engineered cars". Unfortunately Porsche can't select their customer base. That is why you get the impression that the car is unreliable. But ask any real Porsche enthusiasts and they will tell you, it is a great piece of engineering, after all. It is a 12 years old car indeed. Scan it every 3 months, parked or DD, whatever. Make it a routine and you are going to be laughing for the next 25 years (min) with this car |
(wow I sound like a car indy pro mechanic enthusiast).
Should we give credit to 986forum to be dead honest. Most that I've learn about the Porsche in and out is HERE!!!! On this forum. Get that AOS done and stick around, great help....... to built a 'confidence' with this car if you don't have one already ;) |
These cars require preventive measures. Things like the water pump and AOS are items that require proactive replacement and these are well-known issues.
How many reports like this one do people have to read to finally believe that it CAN happen to them? |
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Tracked cars will need more bolt on parts swapped? The IMS thing is almost like something Las Vegas dreamed up. What are my odds?? Some look perfect when pulled from 120k mile engines. Oil at 5k. Mine looks as gold as when I poured it in. Agreed again, but swapping parts just for prevent if zero wear signs? Maybe IMS because you can't see it, but most other parts cry first, like the AOS. Mine had oil all over it. Just had to visually inspect it, but that required removing the engine cover. |
Jake, what do you recommend as the replacement interval for the Water pump and AOS?
My Boxster is a 2000 S with low Kms (42,000) with original Water Pump and AOS. I have read that a good check for the AOS is to pull off the Oil Cap at idle and if it's difficult to remove then AOS needs replacing. Thanks in advance. |
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Why swap a perfectly good part(s)??? |
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." |
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. |
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. |
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 |
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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. |
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'!
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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 |
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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. |
well hopefully this is one common fault now hopefully that won't come up again now there's a new part in there
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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).
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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. |
happy for ya Tom!
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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 |
http://986forum.com/forums/uploads01/car1384278211.jpg
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. |
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