Some bore scoring... End of the world?
Discussion
My almost mint 996 C2 (52 plate with 40k miles) was recently diagnosed with some bore scoring on two cylinders. It drives perfectly though now its been pointed out you can occasionally see a little smoke coming from one of the banks of cylinders (i.e. one exhaust pipe but not the other) and I have to add a little oil every 1000 miles or so. My question is this ... is it really the end of the world? I know I'll need to keep an eye on the oil level and it certainly won't heal itself but will it just get gradually worse over tens of thousands of miles or will it blow up any minute?
Any advice or views appreciated and just to re-iterate it drives perfectly and you never see any smoke in your rear view when driving.
Any advice or views appreciated and just to re-iterate it drives perfectly and you never see any smoke in your rear view when driving.
The engine is highly unlikely to 'grenade' itself as a result of bore scoring. The most likely outcome is the coating on the affected bores will wear/score further over time, and this will result in a knocking sound as piston slap develops, and in addition, oil consumption will increase.
Speak to Hartech and they will advise as to your options.
Speak to Hartech and they will advise as to your options.
Thanks that makes more sense to me... not an engineer but understand a bit?!? Thats why I wanted to try and understand what the failure mode might be if there are catastrophic failures with this issue. The only thing I could think of is the engine literally running out of oil if it was burning faster than I was topping it up
Patch1875 said:
Just out of curiosity would a Porsche specialist check for this during a pre purchase inspection?
It depends on the specialist and the car.RPM Technik did a pre-purchase bore inspection on the Cayman S that I just bought from them.
I was also talking to 911 Virgin about a Cayman S that they had at the time. They said they wouldn't do a bore inspection.
I've asked loads of people about the issue, professionals and enthusiast alike and I've had a huge range of reactions going from one extreme (its about to blow up any second!) to the other (they all do that to some extent and it will probably be fine to the other side of 100k miles)
.... hence the question
.... hence the question
I agree if it was at all excessive but it really isn't at all. You only see if if its drawn to your attention. Also I'm sure there are loads of threads on here that'll say all 911's smoke a little and its harmless. Thats why i do wonder whether if you were to examine the bores on lots of apparently healthy 911's that you would see some bore scoring but you don't know because there are no obvious symptoms. Maybe it is a genuine example of "they all do that sir" and its just the degree that varies
n3erl said:
My almost mint 996 C2 (52 plate with 40k miles) was recently diagnosed with some bore scoring on two cylinders. It drives perfectly though now its been pointed out you can occasionally see a little smoke coming from one of the banks of cylinders (i.e. one exhaust pipe but not the other) and I have to add a little oil every 1000 miles or so. My question is this ... is it really the end of the world? I know I'll need to keep an eye on the oil level and it certainly won't heal itself but will it just get gradually worse over tens of thousands of miles or will it blow up any minute?
Any advice or views appreciated and just to re-iterate it drives perfectly and you never see any smoke in your rear view when driving.
Unless you are adding a quart every 1000 miles it can't be much bore scoring. If the CEL is off and the engine otherwise runs fine it can't be much bore scoring.Any advice or views appreciated and just to re-iterate it drives perfectly and you never see any smoke in your rear view when driving.
Hard to justify the expense of doing anything -- and just about anything you do will be expensive -- on nothing more than some signs of scoring (which BTW almost every cylinder will have as the piston goes up and down and this can leave visible but essentially meaningless marks on the cylinder walls) with no real signs of any serious scoring problems.
I took it to Sports & Classics in Knutsford because I wanted to sign up for their manitenance plan. With the plan you pay so much a month and that covers the annual service, MOT etc and also gives a labour only warranty. One of the preconditions is that inspect it first to check for pre-existing problems. They reported this amongst a few less significant things and declined to let me take up the maintenance plan. I've had all the smaller things fixed
They have a great reputation and thats why I went there. The service I received from them was excellent and I'm not suggesting for a moment that they have mis-diagnosed a problem. The debate is how serious the problem really is. Their stance was that a rebuild was required to cure the problem... or that I should sell the car
Gassing Station | Porsche General | Top of Page | What's New | My Stuff