Can a loose oil filler cap cause an engine havoc?

[Knudsen]

Hi.

I have just had the unpleasent experience of an engine having to be replaced on my Carrera S. After being driving with good acc/dec and quite fast cornering, the engine started to sound very suspicious and I stopped after 100 meters.

What I noticed was that the oil filler cap was loose and it looked like a small amount of oil had been spilled. When I checked the oil level at the on board computer, it showed OK but in the lower end of the scale.

Nevertheless I got the car pulled away to Porsche who concluded, that a bearing in the lowest part of the car between the engine and the gearbox had been destroyed and therefore there were metal parts in all the oil and engine.

The result was a total rebuild or a new engine.

By the way it had only run 12.000 miles.

Anybody who can answer me how this could happen? Did the loose oil filler cap have an influense on the oil pressure and thereby maybe a loss of oil to this bearing? Or can it be the effect of the oil level not beeing in the high end of the scale?

Thanks

Knud

[1schoir]

Hi.

I have just had the unpleasent experience of an engine having to be replaced on my Carrera S. After being driving with good acc/dec and quite fast cornering, the engine started to sound very suspicious and I stopped after 100 meters.

What I noticed was that the oil filler cap was loose and it looked like a small amount of oil had been spilled. When I checked the oil level at the on board computer, it showed OK but in the lower end of the scale.

Nevertheless I got the car pulled away to Porsche who concluded, that a bearing in the lowest part of the car between the engine and the gearbox had been destroyed and therefore there were metal parts in all the oil and engine.

The result was a total rebuild or a new engine.

By the way it had only run 12.000 miles.

Anybody who can answer me how this could happen? Did the loose oil filler cap have an influense on the oil pressure and thereby maybe a loss of oil to this bearing? Or can it be the effect of the oil level not beeing in the high end of the scale?

Thanks

Knud

Knud:

From your description, "... bearing in the lowest part of the car between the engine and the gearbox...", it sounds as though the Porsche dealer may have been referring to the infamous IMS (Intermediate Shaft Bearing). If that is the case, your engine suffered the fate of some M96 engines. When the IMS bearing and its support bolt and flange fail, there will typically be lots of metal debris in the oil, which then carries it to the internals of the engine.

Call back the dealer and ask them if that is what they were referring to. Also, if it was a rebuild of your own failed engine, ask them about what type of IMS bearing and supporting flange they installed. I would also want to know how thoroughly they cleaned up the metal debris and about what type of warranty they are offering on the rebuild. A very early oil change (100 miles) and an inspection of the oil and of the oil filter pleats may give you some peace of mind.

Do a search here for IMS and you will read many stories of similar failures.

Sorry that you experienced the failure, and glad that you are back on the road.

Regards, Maurice.

Edited October 19, 2010 by 1schoir

[Knudsen]

Hi.

I have just had the unpleasent experience of an engine having to be replaced on my Carrera S. After being driving with good acc/dec and quite fast cornering, the engine started to sound very suspicious and I stopped after 100 meters.

What I noticed was that the oil filler cap was loose and it looked like a small amount of oil had been spilled. When I checked the oil level at the on board computer, it showed OK but in the lower end of the scale.

Nevertheless I got the car pulled away to Porsche who concluded, that a bearing in the lowest part of the car between the engine and the gearbox had been destroyed and therefore there were metal parts in all the oil and engine.

The result was a total rebuild or a new engine.

By the way it had only run 12.000 miles.

Anybody who can answer me how this could happen? Did the loose oil filler cap have an influense on the oil pressure and thereby maybe a loss of oil to this bearing? Or can it be the effect of the oil level not beeing in the high end of the scale?

Thanks

Knud

Knud:

From your description, "... bearing in the lowest part of the car between the engine and the gearbox...", it sounds as though the Porsche dealer may have been referring to the infamous IMS (Intermediate Shaft Bearing). If that is the case, your engine suffered the fate of some M96 engines. When the IMS bearing and its support bolt and flange fail, there will typically be lots of metal debris in the oil, which then carries it to the internals of the engine.

Call back the dealer and ask them if that is what they were referring to. Also, if it was a rebuild of your own failed engine, ask them about what type of IMS bearing and supporting flange they installed. I would also want to know how thoroughly they cleaned up the metal debris and about what type of warranty they are offering on the rebuild. A very early oil change (100 miles) and an inspection of the oil and of the oil filter pleats may give you some peace of mind.

Do a search here for IMS and you will read many stories of similar failures.

Sorry that you experienced the failure, and glad that you are back on the road.

Regards, Maurice.

Thanks for the answer Maurice. I will look up for topics regarding the IMS.

The engine was never rebuilt, but replaced with a brand new. My question is more how this bearing could fail? And how I can avoid the same problem in the future? (It tends to be quite expensive to change the engine :censored:

Best regards

Knud

[Mera]

Hi Knud,

Sorry to hear your story. I am in the UK and had to have an engine rebuild on my 2006 C2. Which year is your car? I hear new engines for Porsches in Scandanavia are very expensive, so much that one was shipped to Autofarm here near where I live to be rebuilt.

Sam

[1schoir]

Thanks for the answer Maurice. I will look up for topics regarding the IMS.

The engine was never rebuilt, but replaced with a brand new. My question is more how this bearing could fail? And how I can avoid the same problem in the future? (It tends to be quite expensive to change the engine :censored:

Best regards

Knud

Knud:

Take a look at the following article...it should answer most or all of your questions regarding the problem IMS: https://www.lnengineering.com/ims.html

The only question that remains in my mind about the "upgraded" design offered by LN Engineering is how lubrication is provided to the new, non-sealed, ceramic bearing.

Regards, Maurice.

[PAULSPEED]

I do not believe that a loose oil cap would cause an

ims problem. Note that there are three oil pumps

on a 997-1. With three pumps, you do not need to warm up

the motor to drive.

There is a line from the motor to the oil seperator to the

throttle body, but this would be more emission problems

then oil pump problems.

Most of the replacement motors are hand built and not

machine built so you should have a better motor than a new one.

Paul

[RFM]

On a factory rebuild M96/97 engine is a paper label, removed by the importer or dealer and attached with the other documents to complete their administration, there is indicated included the name of the laborer, the workshop manager and the site. It shows that they are build in East Europe mostly by women, which is not to say that they are inferior or superior, after all Cayenne car body's are also build in the Czech Republic and brought by train to be finished. That's just a different approach than "hand build and better than new" they meet the established factory quality standards but no more or less.

[Knudsen]

Thanks for the answers guys :thumbup:

To Maurice: Thanks for opening up my mind about the phenomenon "IMS"

To Mera: Sad story about your car - but half the cost as my replacement ;)

It is an 2005 Carrera S so I guess the new engine will not have the IMS problem (As far as I can see in the threads - 2006 and later should be OK)

To RFM: Hopefully I should not worry about that since the replaced engine seems to be brand new.

To Paul: Thanks for the info about the pumps/loose oil cap

Knud