997 Gen 1 3.8S Dates & Info

[cp81]

Hi, for assisting with research into a manual Gen 1 3.8S 997, I am looking for information on dates when changes were done, such as in 2006 there were some engine changes but can't seem to find specific date and / or engine number plus change details.

I guess this has been raised before, but would appreciate some assistance.

Many thanks

[Porsche911R]

2004-2008 the engine is really the same, and any minor changes will be hard to tie down, although people might have a bit more info on the IMS or revised larger IMS bearing which came in around 2006.
Bore scoring is a bigger issue on these engines but I guess with the 3.8s a 2007 model year is a better option.

In that time Porsche also offered the x51 power kit to the engine and in 2009 the new dfi unit came out.

I don't think I would ever bother with a 2004-2008 gen 1 911, that money gets you into a gen 2 Cayman and a bit more into a 2009 911.

Edited by Porsche911R on Tuesday 21st February 13:13

[vernz]

When I had my 2005 (55 Plate) C2S back in 2012, I did some research into the engine numbers and found that mine had the larger bearing. I assume I found the info on Pistonheads.

Not entirely scientific I know, but I suspect that a 2006 car would almost certainly have the larger bearing.

I also had the lower opening thermostat fitted straight away to help keep the oil temps lower. Considering the relatively low costs involved, it was a no brainer to me.

I'm not suggesting it will immune you from the dreaded bore scoring, but it should help minimise the issue, although this would obviously depend on the miles covered up to that point and if negative driving styles as outlined by Hartech had been avoided.

Be prepared for sleepless nights without a warranty!!

[STiG911]

cmoose is right - a 2006 to 2008 car will have the larger IMS bearing which can't be replaced without dismantling the whole engine because it's the only way the shaft can be removed. This is why removal of the bearing seal is recommended on cars in this age bracket when the clutch is replaced as it helps the bearing get sloshed with engine oil.

I've also found some partly useful info on Rennlist which I'm trying to verify elsewhere, but it states that depending on your engine number:
Double Row Bearing: up to 661 14164
Single Row Bearing: from 661 14165

If I find more, I'll update this.

[lowdowntwotone]

Info on Revolution Porsche Web site

Base engine (3.6) has designation “M96”, can have the smaller IMS or revised larger bearing, you will need to know your engine number in order to determine which one you have:

Engine (3.6) number up to M96/05 69507475 has the smaller IMS bearing and Engine number from M96/05 69507476 has the larger revised IMS.

“S” Engine (3.8) has designation “M97”, can have the smaller IMS or revised larger IMS bearing:

Engine (3.8) number up to M97/01 68509790 has the older IMS bearing and Engine number from M97/01 68509791 has the larger revised IMS.

I opted for a 2007 C2 car in my search in the end. The 3.6 suffers less from the cylinder issues too from what I've read. But I had the same thoughts in my search.

Had the car a year now 5000 miles later and no issues yet. Only issue I've had were that the exhaust clamps and bolts needed changing due to corrosion, but this also seems a common problem on the 997 and something to check out as well...

[cp81]

Interesting, I thought I read somewhere Porsche improved the coating process as well during Gen 1 phase.

Also that oil should be regularly changed on the car and correctly warmed up before opening it up?

Another point are the Cab version less popular than the coupe? Prices seem all over the place.

Does anyone uses any other warranty than Porsche?

[PhilboSE]

Porsche911R said:

...and in 2009 the new dfi unit came out.

July 2008 were the first deliveries into the UK.

Though I agree with your sentiment about avoiding a later model 997.1 and go with a Cayman or 997.2.

[cp81]

Process improvements I was referring to was plating on the bore or hard cast alloy in the blocks, as these engines don't have cast iron liners. It was something I read somewhere (but can't seem to find it now...), and just wished to confirm if it were true.

[Lox]

anonymous said:

[redacted]

Unfortunately, I think that's right. I was speaking to an indy recently (one of the very best) and he mentioned how busy he was with 997.1 engine work. Wanting to sound knowledgeable, I confidently presumed out loud that he was referring to 3.8s, but he said no, 3.6s too. It's a real shame.

[lowdowntwotone]

Yeah your right both engines are probably prone to the same problem but several sources believe the 3.6 is less prone. Another point I've seen more cars advertised with engine work/rebuilds being done on Triptronic cars.

porscheinspections.com advise

Q: Should I worry about bore scoring on a Gen 1 997 or Boxster/Cayman?

A: The reality of this problem is quite different than some (with vested interest in the repairs) would have you believe. There have been a small number of failures, but these appear to have been confined to the larger engined or powerkit models (997S, Cayman 3.4, 3.6 996 X51 for instance). It does not appear to affect so much the 3.6 997, the 320hp 996s, 986 and 987 Boxsters and Cayman 2.7. It does not affect the Turbo or GT models, which have a different engine.........