Anyone speak mechanic?
 

I'm looking into a 2005 987 base, (84k miles) and I have the service records from the current owner. The latest service record shows that the AOS went boom, and was replaced.

Notes at the bottom of this record say,

"May have spark plug contamination from oil consumption.
Possible contamination of catalytic converter.
Engine is running ok at this time."

The owner says the 'ok' remark just means, running within expectations.

What do all y'all think?

If the AOS was just replaced it obviously sucked some of oil back up through the intake, that's probably where the oil on the plugs came from.....

You can always expect something to go wrong... lol has it had any other major stuff done like IMS etc?

No, the IMS was inspected, and judged to be a candidate for retrofit, but it was not done. And I only have the records of the current owner, going back a few years.

How was the IMS inspected? No way in hell would I do all the work to remove the transmission, flywheel, remove tensioners, lock the cams and remove the IMS cover and then NOT replace the bearing. You've already done 90%of the job at that point.

If by inspected they mean that it wasn't a nasty goo covered cover so it must be fine, they are kidding themselves. My cover looked perfect.

As to your original question I would say the car was probably wiping out the mosquito population and the plugs were oil fouled. They evidently cleared themselves once the car stopped ingesting oil.

I would find out how long it was driven with the bad AOS. That can muck up the converters if ran that way long enough. Replacing the cats is not a cheap fix, spark plugs are though.

I'd worry about the "candidate for retrofit" as to what they meant. If they meant the IMS is at a failing stage then you better get that replaced asap. If it goes, you're looking at a engine rebuild or installing another engine.

Interesting how someone can say they 'inspected' the IMS bearing... LMAO
I would mark that into your cost as I would have that done just to be sure, but that's just my opinion.

Anyhow, I'm sure you'll get all sorts of comments, but IMO if the services haven't been done at a certified Porsche dealer I would get at least a second opinion from a reputable shop.

The story is that it was only driven a matter of minutes after the AOS failed.

Notes from the IMS check:

"Inspect engine for build numbers. M96. Advise if IMS bearing is replaceable. Connect scan tool and check cam deviation: (plus)1.703 (minus) 1.203. Engine is candidate for IMS bearing replacement.

You can run your VIN to see if the IMS is a retrofit candidate. If yes, have it done along with the clutch if original. 2005 is likely a single row IMS which has a much higher failure rate.

Interesting. I thought it was impossible to know without opening it up and looking.

What's the ballpark cost of clutch plus IMS for an '05?

This statement is true for every car that ever had an AOS fail. Shop was just covering their arse in case something came up later. If the engine is running fine and there are no codes, then the odds are very good that everything is fine.

Typically between $2-3k depending on if the flywheel also needs replacing.

More detail on the IMS retrofit.
IMS 101

Quote:

Originally Posted by Finnegan (Post 445264) I'm looking into a 2005 987 base, (84k miles) and I have the service records from the current owner. The latest service record shows that the AOS went boom, and was replaced. Notes at the bottom of this record say, "May have spark plug contamination from oil consumption. Possible contamination of catalytic converter. Engine is running ok at this time." The owner says the 'ok' remark just means, running within expectations. What do all y'all think?

What stone said.... I agree 100%

These are good numbers and if it were mine I'd drive and regularly inspect the oil filter for contamination. If there is no unusual tapping in the top or bottom of the engine I'd say the AOS did no damage. You can have one fail that doesn't hurt anything. Mine blew at high RPM on track dumped all sorts of smoke for several hundred yard and stopped stalled. Pulled off track it fired and drove back to the pits and did no damage at all.

Doesn't the 987 require splitting the engine case to get at the IMSB?
Cam deviation numbers look well within spec tolerances
Catalytic converts ingesting oil could certainly be a concern. They are expensive to replace. If no codes are being thrown, of course someone could easily clear any

There are posted ranges of serial numbers and not all 2005 require the case being opened. I recently saw a new posting that said no 2005 and early 2006 model were exempt from being opened. All of those that need split have a more substantial bearing that are good candidates for oil injection flanges.

Same for me. I've gone thru two AOS failures with no collateral issues.

We keep seeing this information posted, and every time we check the supposed "lists" against VIN and engine numbers we have from actual disassembly's, they come up wrong. Proceed with caution.

In my industry we call it traceability. If a plane crashes we can follow every single part back to the hole in the ground the ore was dug out of. It seems insane, and is very, very costly. But this is necessary in order to understand what caused a crash and to pinpoint the issue so it doesn't happen again (was it a bad design, were the materials defective, was it installed properly, was there a non approved repair, do the manuals ever tell you to look at this thing occasionally, etc).

Apparently the automotive industry doesn't even feel the need to hat tip that concept.

It's easy to see how it happens. You have a pending design change (for cost, ease of assembly, product improvement - let's assume that going from the original double row to single row IMS was a cost cutting measure because it surely didn't improve the product.

You line up a supplier for the new part but it's going to take a while for them to come up to the rate you need in order to keep your line moving. Add to that, you may have a contract with the current supplier that has several months worth of inventory that you have already committed to paying for. Do you s*** can those parts to make a clean VIN break? It would have made our lives easier as end users to be sure. But if the parts were deemed "good enough" then some bean counter will surely want to use them up.

We still allow for some mixing in aerospace, but we know exactly which planes got which part. I wish I could say I spend all my day designing cool stuff, but there is administrative tasks associated with calls from the field. "Hey, I've got a XXX built in 1989 and the dingus isn't working. Can I get that part?"

I am able to look up exactly what options that plane had when built. Every part number, every revision level. If that part has been superseded I can tell you what part to ask for.

Sorry for the off topic.

I work for an aeronatical company myself. There is a reason keeping an aircraft airworthy is expensive. When a car breaks down you usually just pull to the side of the road. Can't do that with a plane.

Porsche is nearly legendary for lousy record keeping, particularly on transitional time frames. The switch from dual row to single row IMS bearings (2000-2001) is perfect example, none of their records accurately will tell you what is in a given car. The 2005 model year is exactly the same way, the only method that has proven accurate in determining which style IMS is in the car is to take it apart and look.