Anyone speak mechanic?

[jsceash]

Originally Posted by Finnegan

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.

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.

[kk2002s]

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

[jsceash]

Originally Posted by kk2002s

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.

[JFP in PA]

Originally Posted by jsceash

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.

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.

[flaps10]

Originally Posted by JFP in PA

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.

[Porsche9]

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.

[flaps10]

Originally Posted by Porsche9

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.

Especially when it glides like a man hole cover.

[JFP in PA]

Originally Posted by flaps10

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.

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.

[kk2002s]

So the 987 was suppose to get the M97 engine?
Leftover inventory of M96 engines into the new 987 model year?

[thstone]

Originally Posted by jsceash

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.

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

[mikefocke]

The problem I see is he doesn't know if the cam deviation was bouncing, just got some meaningless single time deviation figures. The fact that it was a "candidate" could mean that it was seen to be of a type that could be replaced. Or the mechanic saw bouncing. But we don't know which.

You can't tell much from the VIN or engine number as to which generation of bearing is in the unit, gotta have the trans off and look at the bearing cover. Ask the mechanics who have been surprised at what they found actually in the engine wasn't what they had ordered.

The mechanic is just covering himself with the "other things could be wrong" comments after the AOS replacement. He didn't say he cleaned the intake and throttle body.