Engine Failure Facebook Group

[mts]

Originally Posted by jcb986

Boxsters have no more engine problems than any other car on the market. :

I do not buy that at all. I don't believe the 20% failure rate, but I wouldn't be surprised at all at 2-5%. And by failure rate I don't mean $2k repair and you are out the door, we are talking $10k and up complete rebuilds/replacements. By any statistical measure 2-5% for complete failures is horrific compared to other top cars on the market.

Yes, I am one of the one that has experienced an IMS failure and am dealing with aftermath of that now on a 2004 car with 20k miles. However, Excellence Magazine has devoted 2 full articles (with a 3rd one due later this year) to the IMS issue and the lead guy dealing with the repairs/upgrades (Flat 6) is working on a 2 month to almost 1 year back-log depending on what is needed. Those facts alone tell me the issue is not insignificant.

[Boxtaboy]

Originally Posted by mts

I do not buy that at all. I don't believe the 20% failure rate, but I wouldn't be surprised at all at 2-5%. And by failure rate I don't mean $2k repair and you are out the door, we are talking $10k and up complete rebuilds/replacements. By any statistical measure 2-5% for complete failures is horrific compared to other top cars on the market.

Yes, I am one of the one that has experienced an IMS failure and am dealing with aftermath of that now on a 2004 car with 20k miles. However, Excellence Magazine has devoted 2 full articles (with a 3rd one due later this year) to the IMS issue and the lead guy dealing with the repairs/upgrades (Flat 6) is working on a 2 month to almost 1 year back-log depending on what is needed. Those facts alone tell me the issue is not insignificant.

I wonder if the 04 SE in particular, was a problem edition. I've seen at least 04 Special Edition Boxsters with IMS failures on various Pcar forums over the years. Was yours an SE?

[mts]

Yes, mine is an SE, but based on what my research has turned up its not an SE problem, it's any M96 motor installed in the Boxster and Carrera models.

[Boxtaboy]

Originally Posted by mts

Yes, mine is an SE, but based on what my research has turned up its not an SE problem, it's any M96 motor installed in the Boxster and Carrera models.

Yep, I realize it affects all M96 based engines. Just that I've seen a lot of 04 SEs pop up as being hit with it. Thought maybe a bad batch of bolts/bearings that production run.

[Dave S.]

This is my first Porsche so bear with me here, but until I was researching this car I had never even heard of an Intermediate Shaft before. I've never had a car or motorcycle with a boxer type engine before, so I assume it's something unique to that design.
From what I've learned on this forum, I was surprised to see the bearing that fails is such a small unit. What function does the IMS perform in the engine?

[mts]

Dave S - There is a great article on the IMS, what it does, symptoms of failure and ramifications in the June 2010 edition of Excellence Magazine. It has diagrams and pictures. Subscribers got the edition earlier in the week, not sure when it will hit the news stands, but its worth picking up for that article alone.

[blue2000s]

Originally Posted by Dave S.

This is my first Porsche so bear with me here, but until I was researching this car I had never even heard of an Intermediate Shaft before. I've never had a car or motorcycle with a boxer type engine before, so I assume it's something unique to that design.
From what I've learned on this forum, I was surprised to see the bearing that fails is such a small unit. What function does the IMS perform in the engine?

I've never seen an intermediate shaft used on anything but a Porsche. Someone else will know, but I suspect it may be a remnant of the old VW boxer 4 that started it all.

It's a shaft that spins below the crankshaft and is driven off the crankshaft. It drives a few accessories, and through a set of chains, also drives the camshafts. On the water cooled engines, the intermediate shaft is driven off the crankshaft by a chain as well.

In the most recent engines, Porsche has eliminated the intermediate shaft and drives the camshafts from the crankshaft, as other OHC engines do.

[Bladecutter]

Originally Posted by blue2000s

I've never seen an intermediate shaft used on anything but a Porsche. Someone else will know, but I suspect it may be a remnant of the old VW boxer 4 that started it all.

Actually, I recently learned that the Ford 4.0 SOHC V-6 engine in a lot of Ford Trucks (Ranger Pickup, Explorer, F-150, etc) also has a sort of IMS that drives the camshafts, similar to the Porsche.

Those engines also seems to have fairly high rates of noise and failure.
At least they have noises first to let them know something bad is going on.

They don't actually have an IMS bearing, from the little bit that I've looked into it, however. The problems that they run into are related to the tensioner assemblies failing, causing the camshaft timing to go out of whack, and then pistons meet valves at high speeds, causing massive damage, and big engine replacement dollars spent.

Sometimes, the tensioner assemblies fail in such a way, that the parts punch a hole either into the engine block, or the valve cover assemblies, which then sends shrapnel down into the engine, taking out other important parts.

Not good, either way.

This engine family was originally a pushrod engine, that was modified to accept a cylinder head design that had overhead cams. The original camshaft location in the block was used to house the IMS that feeds the chains to the cams in the cylinder heads. Just an under engineering example.

BC.