Engine Shutdown - did it blow at 45K miles?

[racerken]

Hi,

 

I have a 2008 Carrera C2 997. Oil is 8 months old, coolant good, plugs < 3k miles...

 

Today, the following events took place within 1/4 mile, 30 seconds:

1. I noticed a lack of engine power.

2. smoke from the passenger rear pipe so it's the driver side bank.

3. engine check light or something like 'visit engine shop'. I can't reproduce that message.

4. the engine just shut down.

5. smell of burnt oil.

 

Upon opening the engine compartment, I did notice that the oil cap was lose.  Oil is 2 bars below high bar.

 

Can someone recommend some discovery steps?  I'm definitely going to drain the oil to see what it looks like.

 

I guess smoke can only come from the piston rings, valve seals, head gasket?

 

Darn it.

 

In need of beer.

Edited April 20, 2015 by racerken

[j_beede]

Sorry to hear this report racerken.

 

Every blown head gasket I have expeienced (wet sump engines) was accompanied by foamy or creamy look to engine oil

"Reading" the spark plugs from both banks may give some clues, dry? wet with oil? wet with coolant?

FYI: Every case of IMS bearing failure I have heard of was accompanied by a large volume of oil on the ground.

No unusual noises?

 

I would avoid any attempt at starting until discussing the situation with a Porsche mechanic.

[racerken]

Hey J_beede,

 

I had a 996 and experienced the IMS failure first hand and the sound from the engine was clanking during IMS failure.  This time, no noises, just a lack of power as if it were running on 5 cylinders and then it died.  Anyway, I'll dump the oil tomorrow and provide feedback.   

Edited April 20, 2015 by racerken

[JFP in PA]

These engines use MLS head gaskets, and I have never seen or heard of one failing.  Cylinder heads crack, but the head gaskets have proven to be bullet proof.

 

We have also seen our share of M96 IMS failures; some of the engines were internally devastated, but never dropped a spec of oil or coolant on the ground.  The most common description of the IMS failure was that the engine started to shake or make an odd sound, lost power, and then just stopped.

 

You may have suffered a catastrophic AOS failure, which will suddenly suck in a lot of oil into the engine, eventually stalling it.

 

If the car threw a code, it should still be retained in the DME, so along with checking the oil filter for debris, I would scan the car without starting it.

[racerken]

Hi JFP,

 

I drained the oil today and it was typical, no water, no emulsion....

 

This is pointing towards your assessment of the AOS.

 

I have a Durametric inbound so I should have it soon so I can check out the error codes.

 

Can the AOS be replaced with the engine mounted or do you think I need to drop it?

 

Thanks!

 

Ken

[Hilux2400]

I was easier to drop the engine slightly, but it was a job that was being done at the same time as a new coolant reservoir and the extra space was needed.  Replace the oil filler hose at the same time as the AOS. 

[JFP in PA]

Hi JFP,

 

I drained the oil today and it was typical, no water, no emulsion....

 

This is pointing towards your assessment of the AOS.

 

I have a Durametric inbound so I should have it soon so I can check out the error codes.

 

Can the AOS be replaced with the engine mounted or do you think I need to drop it?

 

Thanks!

 

Ken

 

You did not say the year or model, but assuming you have a 997, yes, you need to lower the engine and push it to one side slightly to get at the AOS.  It is in a tight spot, making it a bit of a pain, but it is doable.  You can also test for a failed AOS by trying to remove the oil fill cap with the car idling, if it is difficult to get off, the AOS is gone.

[racerken]

997! 2008 Carrera with 3.6L, nothing special, stick, silver, looking very sad in the garage.

 

One thing I did notice that the oil cap was lose when I initially checked it.  Just out of curiosity, if the oil cap is lose and you're driving around, will this create error codes, engine shutdown?  if the answer is yes, I'm just going to yell.  

[JFP in PA]

997! 2008 Carrera with 3.6L, nothing special, stick, silver, looking very sad in the garage.

 

One thing I did notice that the oil cap was lose when I initially checked it.  Just out of curiosity, if the oil cap is lose and you're driving around, will this create error codes, engine shutdown?  if the answer is yes, I'm just going to yell.  

 

Because the engine case is under s slight vacuum (around 5 inches of water), the could code for a vacuum leak if the cap was loose enough.  But that would not explain the smoke or the engine shut down. 

[tommyt]

I had an 03 Boxster that stalled and died with a large gray mushroom cloud hanging over it - ended up being the AOS - not too costly as I recall but it was pretty traumatic!

[dphatch]

Hi JFP,

 

I drained the oil today and it was typical, no water, no emulsion....

 

This is pointing towards your assessment of the AOS.

 

I have a Durametric inbound so I should have it soon so I can check out the error codes.

 

Can the AOS be replaced with the engine mounted or do you think I need to drop it?

 

Thanks!

 

Ken

If it was the AOS there will be evidence of oil in the intake runners just aft of the intake plenum. As removal of the intake plenum is needed in order to access the AOS you won't be wasting any time should you find a good deal of oil in the intake tube. AOS can be replaced without dropping the engine and there is a very good DIY on the process on one of the Porsche boards. I replaced the AOS myself and while time consuming it's not impossible. Google it and you will find it. It is essentially the same process as replacing a failed alternator/battery cable ( with a few extra steps ) which I would highly recommend doing at the same time should you decide to replace the AOS.

[racerken]

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Edited April 27, 2015 by racerken

[racerken]

Hi,

 

I removed all the spark plugs and discovered that Plugs 1 and 4 are gummed with oil.  Plug 1 has burnt oil flakes on the electrode but Plug 4 is just oily. I'm assuming that this is indeed an AOS issue so I'm continuing my strip down.  JFP, you are correct in your diagnosis - well thus far.

 

Thanks.

 

Ken

[racerken]

Hi,

 

I received my Durametric today and the following error codes appeared:

 

P0203: Injector Circuit Cylinder 3

P0267: Injector Circuit Cylinder 3

P0300: Misfiring Checksum error

P0303: Misfiring Cylinder 3

 

Strange because Cylinder 3 shows no sign of fouling.  Cylinder 1 had the fouling with burnt oil chips.  Just confirming that cylinder 1 is driver side near the rear bumper, cylinder 3 is driver side front. So based on my web search my problem is injector for cylinder 3. 

 

Any comments?

[JFP in PA]

Cylinder locations:

 

 

P0203 indicates an injector malfunction on cylinder #3, P0267 is for a low circuit on the same injector.  So it looks like #3 injector went off line and created the misfire.  But neither of those faults explains the oil in the intake or on the other plugs.

[racerken]

I have a really stupid question:

1. I can't locate the air oli separator which I thought was somewhere behind the a/c unit but there is nothing there.

2. There seems to be something behind  the alternator and I looked up a part which refers to the 'Oil Mist Collector' = is this the culprit?

3. then online I see the 'Air Oil Separator' as two units and it's underneath the car, so I have to remove the oil pan.

 

Am I completely lost?

[Ahsai]

Figure #20 and #21 here http://www.pelicanparts.com/techarticles/Porsche-996-997-Carrera/09-ENGINE-Air_Oil_Separator/09-ENGINE-Air_Oil_Separator.htm

 

The part http://www.autoatlanta.com/porsche-parts/hardparts.php?dir=997-05-08&section=104-11

 

The ones inside the oil sump are for removing air bubbles from the oil.

[Ahsai]

BTW, just curious have you checked for debris in the oil filter and the oil pan? Also have you removed the serpentine belt, try to crank the engine by hand, and check all pulleys to see if any of them is seized?

[racerken]

Ahsai, I'm reading now.  For some reason I thought that the 2008 was considered the 'later model'...  I guess not.  Thanks.

After I drained the oil, I transfered it to a clear pickle jar and inspected it, then I poured it one liter at a time over a very strong magnet to check for metal and I also used a strainer.  Lucky, no debris.  Pulleys all turn but I need to try cranking.

 

Thanks!!!

 

This is actually very humbling and disturbingly fun.  I still don't trust the dealer.

[Ahsai]

Ok buy why not inspect the oil filter directly? Also what are the cam deviations on both banks read by Durametric? Any recent work on the engine that may have disturbed the injector wiring?

[racerken]

Yes, the oil filter is clean - good news.  The balancer tube shows signs of oil vapors but not heavy.  The intake plenum is clean.  I ran a quick check on the Durametric and no report of cam deviations.  The only impact to the electrical wiring might be my habit of blasting water to remove the Detroit salt from winter driving so I'm thinking that I might have corrosion in the contacts somewhere.  Hence, I intend on removing the injectors and wire harness to conduct a continuity check.

[Ahsai]

Makes sense.

[racerken]

Update:  

The engine rotates, 

there are small puddles of oil in just about each cylinder present when using the bore scope,

I did locate the AOS, it is behind the driver side intake on the side (bank 1 - 3).  In an attempt to reach it I removed the generator but failed because I cannot reach the last inner-most screw (closest to firewall).  I can reach the lower screw of the AOS from below but I cannot muscle the bellows hose.  I even attempted to remove the coolant tank but there is interference with the fuel injector cable tray and fuel line...  I even lowered the engine by 30mm.

 

Any ideas before I take the final step?

 

The final episode is to drop the engine.  First i need to order the tall Jack Stands (ESCO) so i can slide the engine/transmission out of from under the car.

This way i can also check the fuel injectors and the relays to solve the durametric error that leads to a bad connection/no-signal.

[racerken]

@Ahsai, the oil filter was clean but I just decided to check all the oil after the dump for sanity.  There were no other deviations reported in Durametric and no previous engine work.

 

Update:  I dropped the engine, swapped the AOL, checked the circuits for the fuel injectors - all is well, now I can't remember how to get the vacuum hoses straight - not enough pictures prior to rip out....

 

If anyone has a 2008 C2 with the PSE, I'd appreciate any pictures of where the vacuum source is located.  I'm now checking out the 997 2 5-05 Sport Exhaust TSB but I need pictures...

[racerken]

I figured it out.  it's the vacuum pump line...  duh.