pongobaz

They are. And scoring is not exclusive to the M96/97 engines, DFI engines can also suffer this type of damage. And so can the air-cooled cars...right Clive?...

theiceman

Air cooled engines are not typical of scoring in this sense of the word and I haven't seen it. Scoring on an air cooled is typically due to a very small piece of hardened metal getting in to the cylinder. I have one or two score lines on a couple of cylinders Yes technically they are scored but you need a very bright light and carefull observation to spot it. Also I have Alusil. Not Nikasil

I wouldn't even hesitate to put these back.

Pics I have seen of water cooler scoring is just unbelievable.

I think my scoring was due to pitting of my cams and material getting in the oil. Non hydraulic lifter engines suffer with new oils. Don't think po ever used boutique oil.

PC Valkyrie

Didn't you tell me you are getting a new P-car?

ansonintoronto

Yes Pat, but the 997 and 991 GTS will be the garage queens and I just sold one of my Corrados....so one more space recent opened up

peteb3

I have one as a DD in Calgary
No issues just regular servicing
IMS and RMS were done at 60k km
I'm now at 101000km
It's been reliable, fun and a great DD even in the crazy weather we get here

rotorite

I have had my '02 4S as a DD year round in Edmonton for about 4 years and am now at approximately 103,000 KM. It has been a fantastic experience up until this year. The IMS bearing failure was addressed with the IMS solution, however this year cylinders 4-6 had scoring from over the winter. As mentioned previously, the cost of a replacement engine is fairly substantial (even for a short block) and rebuilding an engine to address the short comings of the m96 and m97.1 engine can quickly approach the price of the car.

I believe this car is a great DD but with the IMS issue, potential oil starvation issue when run at the track and cylinder scoring issue (which includes not the greatest choice in cylinder liner material, tight clearances and cooling issues), I do not believe I would opt for a N/A 996 or 997.1 again unless it was a turbo or GT3.

halo777

Hey rotorite...

Sorry to hear about your engine. Can I ask, how did you become aware that the engine had cylinder wall scoring on 4-6? Is the car still driveable? Do you know if the problem just started this year, due to age, extreme weather, etc, or has it been a gradual scoring of the wall, that has gotten worse over time?

I am very aware of the cylinder wall scoring issues in the m96/m97. Having done a lot of research before I recent car purchase, I still chose a 997.1 over a 997.2. I dont consider the IMS issue something to worry about in my 08 C4s. However, the cylinder wall scoring issue is a real threat to all m96/m97 engines, especially those driven in cold climates, IMHO.

That being said, if you work out the risk of the issue happening, I still think the m96 and m97 cars are a better value compared to the 997.2s, at the moment. You pay about a $15k premium (at least) for a similar 997.2 over a 997.1. That is a huge chunk towards a new engine. I know there are lots of other things to consider, but I still see these cars as a great value right now. And remember, the 997.2s have cylinder wall scoring too. So there is no guarantee that going to the 9A1 is going to protect you from that.

I'd much rather save the cash and put it towards an engine rebuild with 'nickies' if anything goes wrong. In fact, if you want the most reliable 911 experience (aside from Turbo, GT3) then I would buy a car with a blown engine for dirt cheap, and get a fresh Jake Raby engine put in it. It will cost you in the same neighborhood as if you bought the car with the original engine. But, it takes more work, planning, time, etc.

Anyway, good luck with your car. If you have the time, please post a thread on the repair and results. I like to keep track of all this stuff so I know all the options when I come across 997s, with blown engines.

rotorite

Hey halo777,

Thanks, its not the best news by any stretch of the imagination but I am doing the best to determine my options to make an informed decision.

I had discovered this when my engine started having what is best described as a stuck lifter tap that would come and go mid winter, which by the end of winter had turned into a constant tapping sound along with some oil smoke on cold starts from bank 2. The car was taken in for a bore scope and was diagnosed with 3 scored cylinders on the thrust face of the cylinder.

I agree that his is an issue that seems to be more common in colder climates from what I have read and according to information found by Hartech, it can occur under certain situations too. In my case, the infrequent use and the -30C cold starts were a more probably factor in my situation than the scenario described by Hartech.

I agree with your point about buying a 996 with engine repairs needed for cheap and getting a more reliable engine built with LN Engineering "nickies" and an IMS Solution by a reputable builder (such as Flat6 Innovations).

Thank you and if I decide to revive this car I will for sure start a thread and hopefully have some more discussion about the options there along with pictures of the scored cylinders, etc.

For the OP, if you do decide to get this car, if it does not have a low temp thermostat, that may be something to consider as well.

Turbodan

Doessn't Jake's kit for IMS bearing need replacing every few years or 50k?

halo777

Thanks for the info, Rotor!

Best of luck with the car, whatever you choose to do.

rotorite

Yes the IMS retrofit bearing does have a service life, from what I've read of about 50k, but the IMS solution replaces the bearing with an oil fed journal bearing I believe. The solution needs to be inspected but from my understanding the service life would most likely be closer to permanent solution.

Imo000

Sell the car as-is and move on or get an oil pan/block heater on the next engine.

akatsuki...

So for service for the IMS retrofit, what do you need to do? Just oil it?

I am picking up my new to me 996 C4s today.. it's got a 3.8 rebore rebuild with IMS Retrofit and RMS done. Trying to know more about my car!

Imo000

No, you need to replace the entire bearing/flange assembly. In simple terms, you need to replace it like you never had one.

halo777

That is a good tip. The only really issue that I worry about with my recently m97 is cylinder wall scoring. I dont know if I will drive it next winter, but if I do, I think Ill take that advice.