New 997's, and engine family lines
I received the following by email from a friend of mine in PCA regarding 911 engines.
I am very much interested in any comments by RC and others knowledgeable in the matter of engine reliability as discussed and the prospects for the 997 and 997S engines in this regard.
"Subject: PCA.org/tech New 997's, and engine family lines
Date: Tue, 17 Aug 2004 17:23:19 -0500
You are subscribed to the 964 / 993 / 996 incl. Cup cars area from the PCA.org Technical Q&A Section.
Classification: Engine
Subject: New 997's, and engine family lines
Question:
More than likely, I am ahead of ourselves in asking this question, but I am curious. I am one of those lucky ones who has had NO rms problems with my cab. It has been totally trouble free since new. Even worried me because I rarely used half a quart of oil in 7,000 miles, when I changed. (yes, of course I checked it often!)
Here's my question. I was very interested in your comparisons of the 996 engine, which you mentioned was developed from the Boxster engine, compared to the GT3, and Turbo engines, being developed from the old reliable 911 engines. Do you know, are the 997 engines developed from the same engine as the current 996 Carrerra, or the seemingly more reliable 911 engines? (sorry, I don't know what else to call them) I was wondering if the 997S might have different guts from the standard 997?
Answer:
The 997 engine is an evolution of the 996 engine. I have to believe it will incorporate fixes for the RMS problem, the porosity problems, the cylinder liner coming loose failures, and so on. The S engine will be the same evolution engine but with increased displacement and associated tuning. It may have additional reliability reserves; it will be interesting to see when & how it finally comes.
Your oil consumption figures are excellent. There are many others with no RMS problems, however, people are less likely to write in to report that their car is fine.
That is so well said, "the seemingly more reliable 911 engines". The 993's with OBD-II are coming down with major OBD-II failures, mostly secondary air injection ports clogged. Substantially all of the cars are failing emissions at mileages as low as 30k. About one week out of the 7-year emissions warranty, wouldn't you know. Not for actual emissions, but for failing excessively tight OBD-II tests, so the car fails itself. For a new owner of a used 993 this is a rude welcoming when the car can't be registered in CA, NJ, NY, WA, etc, and the problem was missed by dealer PPI pre-purchase inspection. The light comes on about ten minutes after the car arrives at the owner's home. Even worse for the loyal one-car owner, the car is not going the distance it should. Not even close.
In addition, all or substantially all of the 964 and 993 engines we have seen apart have all had worn out valve guides with way too few miles of service. The exhaust guides can be worn out (or worn close enough to the limit to where they will soon exceed the wear specs if re-used as is) at 10k-20k miles. The intake guides are better, but they are not far enough behind. The 911SC engines could routinely go 125,000 miles or more, in some cases twice that. The valve guide material used for the 3.6 and 3.8 liter air cooled engines is just too soft. The replacecment guides from the US are much better, but an unprompted engine rebuild is a show stopper for most owners.
The turbo engines suffer from the same valve guide problem, except that the wear rate on the exhaust guides is worsened by the additional heat of the turbos. The turbos should also be afflicted by the secondary air problem, but we have few reports on those so far.
Given the above, I would feel best with any of the following:
- 996 or turbo still in warranty
- GT2/GT3 still in warranty
- any Certified Pre-Owned (CPO) Porsche
- 997 because it will be in warranty AND have improvements
- a 964/993 for someone that can rebuild their own engine
- a 964/993 for one that can afford an engine rebuild
So I think your labelling is particularly accurate.
Joel Reiser - PCA WebSite - 8/17/2004"
I am very much interested in any comments by RC and others knowledgeable in the matter of engine reliability as discussed and the prospects for the 997 and 997S engines in this regard.
"Subject: PCA.org/tech New 997's, and engine family lines
Date: Tue, 17 Aug 2004 17:23:19 -0500
You are subscribed to the 964 / 993 / 996 incl. Cup cars area from the PCA.org Technical Q&A Section.
Classification: Engine
Subject: New 997's, and engine family lines
Question:
More than likely, I am ahead of ourselves in asking this question, but I am curious. I am one of those lucky ones who has had NO rms problems with my cab. It has been totally trouble free since new. Even worried me because I rarely used half a quart of oil in 7,000 miles, when I changed. (yes, of course I checked it often!)
Here's my question. I was very interested in your comparisons of the 996 engine, which you mentioned was developed from the Boxster engine, compared to the GT3, and Turbo engines, being developed from the old reliable 911 engines. Do you know, are the 997 engines developed from the same engine as the current 996 Carrerra, or the seemingly more reliable 911 engines? (sorry, I don't know what else to call them) I was wondering if the 997S might have different guts from the standard 997?
Answer:
The 997 engine is an evolution of the 996 engine. I have to believe it will incorporate fixes for the RMS problem, the porosity problems, the cylinder liner coming loose failures, and so on. The S engine will be the same evolution engine but with increased displacement and associated tuning. It may have additional reliability reserves; it will be interesting to see when & how it finally comes.
Your oil consumption figures are excellent. There are many others with no RMS problems, however, people are less likely to write in to report that their car is fine.
That is so well said, "the seemingly more reliable 911 engines". The 993's with OBD-II are coming down with major OBD-II failures, mostly secondary air injection ports clogged. Substantially all of the cars are failing emissions at mileages as low as 30k. About one week out of the 7-year emissions warranty, wouldn't you know. Not for actual emissions, but for failing excessively tight OBD-II tests, so the car fails itself. For a new owner of a used 993 this is a rude welcoming when the car can't be registered in CA, NJ, NY, WA, etc, and the problem was missed by dealer PPI pre-purchase inspection. The light comes on about ten minutes after the car arrives at the owner's home. Even worse for the loyal one-car owner, the car is not going the distance it should. Not even close.
In addition, all or substantially all of the 964 and 993 engines we have seen apart have all had worn out valve guides with way too few miles of service. The exhaust guides can be worn out (or worn close enough to the limit to where they will soon exceed the wear specs if re-used as is) at 10k-20k miles. The intake guides are better, but they are not far enough behind. The 911SC engines could routinely go 125,000 miles or more, in some cases twice that. The valve guide material used for the 3.6 and 3.8 liter air cooled engines is just too soft. The replacecment guides from the US are much better, but an unprompted engine rebuild is a show stopper for most owners.
The turbo engines suffer from the same valve guide problem, except that the wear rate on the exhaust guides is worsened by the additional heat of the turbos. The turbos should also be afflicted by the secondary air problem, but we have few reports on those so far.
Given the above, I would feel best with any of the following:
- 996 or turbo still in warranty
- GT2/GT3 still in warranty
- any Certified Pre-Owned (CPO) Porsche
- 997 because it will be in warranty AND have improvements
- a 964/993 for someone that can rebuild their own engine
- a 964/993 for one that can afford an engine rebuild
So I think your labelling is particularly accurate.
Joel Reiser - PCA WebSite - 8/17/2004"
993 sales were running surprisingly good by that time (after a pretty bad period) and Porsche decided to keep the 996 on hold and put the Boxster on the market first.
