deliriousga

With reading about engine failures several of you have talked about having with the '99 MY that were produced in late '98-early '99, I just read an interesting article in the April, 2005 issue of Panorama magazine I received today.

If you get Panorama, look in the "Tech Q&A" section, page 70. It's the first question and the response is nearly two pages explaining the engine building process and the problem the causes the failures. They say in the article that Porsche has been very good about taking care of the problem whether in or out of warranty, but that's not what I've read in these forums.

The meat: The problem stems from piston ring failure, not RMS as most mechanics seem to have diagnosed. The manufacturer's casting machine broke and they would be delayed awhile with no blocks. "The solution was to reline some not-quite-perfect engine blocks that were on hand. The fix was simple and absolutely acceptable to standards when done correctly."...."This process started by boring out the failed cylinder to allow for the insertion of the liner. There is also a groove cut around the top of the cylinder to keep the sleeve from dropping."...."The next step was the insertion of these liners. It was decided to press the liners in the blocks. However, some of these liners were pressed in at a higher rate than the top retaining ring could handle. This would then fracture the ring at the top of the liner. When this ring failed under operating conditions, it was catastrophic. The ring itself would fall apart inside the combustion chamber. At this time the piston would force this debris up into the cylinder head. The piston rings would grab the liner and pull it down from the momentum of the crankshaft." Originally printed in Porsche Panorama magazine, April 2005, pg71.

I'm guessing it's diagnosed as a an RMS failure because the crankshaft is jerked around pretty hard when the rings fail and the pistons fly in weird directions.

I can't post the whole article online due to copyright, but if don't get Panorama magazine and want to read it, I'll scan it and e-mail it to you if you PM me with your address. The article may help your case with Porsche since most comments have been that Porsche acts like the problem does not exist.

Tool Pants

Here is the proof Porsche did exactly what the article says.

This is the top part of a sleeve that has broken off'

It is from a 1999.

85percent

woah. thank you for the info. this is how my 99 ate the dust. i'd like a copy of that article, i'll pm you.. who do you think i should write a letter to? since a 3.4 996 engine is already being swapped in my boxster at a local mechanic, i'm thinking porsche may reimburse part of it?

dennis a from pa

...uh, this has been discussed often. for at least as long as the '99s started failing with slipped sleeves. The first of which was probably in 1999 !

I know many people thought RMS and engine slipped sleeve failure was related, but many threads here and on PPBB have hashed an re-hashed this issue since 1999....

THERE IS NO RELATIONSHIP BETWEEN RMS AND TOTAL ENGINE FAILURE..SLIPPED SLEEVE.

There may still be some sleeved engines out there whose time is yet to come, or maybe not.

dennis a from pa

...the intermediate shaft failures, which also result in a new engine (under warranty) are few and far between...but DO occur. These are not related to RMS leaks either, BUT when RMS leaks are fixed...new epoxy coated bolts are replaced on the rear of the intermediate shaft bearing.

I don't know if there is a reasonable repair for this failure out of warranty, but right now I know of no one whose has repaired i.e. torn down this M96 motor..it may eventually be done, but hasn't yet, as far as I know.

Palting

Interesting article. The Panos are still sitting on my desk, waiting to be opened. I'll read them when I get home.

I agree with Dennis. The problem described results in catastrophic engine failures. There is no "partial failure" that would result in a "wobbly" crankshaft giving rise to the RMS. Plus, the problem of the liner and catastrophic failure is limited to engines that were done in that short period. RMS continuous on beyond that period. They are separate problems.

deliriousga

Thanks Dennis and Palting for clarifying the differences for me. I haven't had either problem and the comments get mixed together so much in the forums I thought they were related. I don't go to the Pelican boards because rennlist has many more members in the 928 forum, the main forum I'm in. My bad.I don't mean to "rehash" the issue, just offering info to try and help if you've experienced the '99 MY engine failure. If you've had the RMS problem, this won't help you.

Have a great day folks!

85percent

maybe this topic IS beating a dead horse to a few of you. but to me it's very helpful- as i'm sure it is to several others.

so if you look at the title of the thread, and are sick of seeing it, i dont know, dont click on it?

dennis a from pa

...just trying to keep people from worrying about a catastrophe that is not related to the RMS issue.

Even if you have a '99 built within that time frame, it is not necessarily a sleeved motor...AND if it is it won't necessarily fail.

Also the intermediate shaft failures are NOT common, but have occurred in some cars irrespective of year and model i.e. 2.5s,2.7s AND 3.2s...don't know about the 3.4s or 3.6s.

RMS leaks do not cause any of the above.