Porsche Enthusiasts Club Forum

Well guys n' gals it's with a heavy that I have to report that my 997 gen1 that I use daily has got bore scoring to pot 6. Ok I've done 114k in miles but I'd hoped that I would never get it, as oil & filter serviced 2 or 3 times a year depending on mileage & when (if) tracked. I took great care to remove the potential of this ever happening, never booted until all needles showing above 90degs.

Have decided to repair & replace all 6 pistons, rings, liners along with the bearings, IMS & tension chains. Privilege is going to be in a bill in excess of £5k............so not going to be on the road for 4-6 weeks as going to have to find the money.

a bloody frustrated Porsche owner
Stu

Blimey mate , that is tough luck!!

Bad luck. Who is doing the work ?

I've got Richard at RSR CO-ordinations the work. He is taking out engine & stripping, the sending away to get new Westwood liners, whilst a Porsche tech friend will fit new pistons & IMS. Richard will fit new ceramic RMS bearing if required and the he'll put back together.

The Westwood liners are fitted by Parr Motorsport & come with warranty when fitted by their specialist, hence the engine is going on a trip. More info:
http://www.westwoodcylinderliners.co.uk ... 15&month=1

Will you be doing any work to prevent further issues, i.e on the cooling side of things. Obviously we all read the Hartech articles and forum posts about the reasons they believe cause the bore score problems.
Is there a reason you chose Westwood liners over the Hartech liners ?

Thanks for any replies, just interested in case I have problems in the future, plus I have a friend that is having issues at the moment after an engine repair/rebuild with the same problem arising after only 500 miles of careful running in. Not sure where his engine was done though.

The work carried will include low temp oil switch & lots of new seals, bearings, gaskets & tension chains. There is not much I am not doing whilst there. And will run on thicker oil as per Hartechs advice (Millers XFS 5w 40).
As for the liners Porsche techie I am using has used them several times before & everything comes with the same 2yr guarantee as Hartech & also supported by the AA.

Good luck with the rebuild and I hope you will report the build on here.

That's not good! You must be disappointed especially as you mention that you observed all the precursors to prevention to no avail!! Sounds like you are planning to undertake a top notch repair, I wish you every success with it and like others would be very interested in your experiences with the process you are to follow and it's outcome.

How did the problem manifest itself? Was it a rattle on start up, or after a few miles with a cold engine? Or both, or on a hot engine? Or was it the engine smoking and excessive oil consumption, or a combination?? Did it occur over an extended time or was it a case of not there one day and was the next?

Would be really interesting to have the knowledge of your experience on this one if at all possible.

No major issue past until 2wks ago when oil consumption went through the roof & when booted left a trail of black smoke behind.

No previous issues spring to mind, except petrol consumption slightly higher than normal, but speaking to Hartech today they think this connection unlikely. Caught issue very early & has not started rattling, just higher oil consumption. Boroscope showed scoring on liner in pot 6 & debris on top of the piston. No issue with mishaping of piston or liner, probably only done 250 miles since suspecting issue, but not heavy driving, kept revs under 3k & ensured not put under any strain. Since boroscope on Saturday just left in specialists garage & not used.

Running through some figures today price is creeping up & may have to prioritise where & what I spend my money on, but will keep you posted hopefully with some pictures.

Cheers for the update.

So it was a fairly rapid final destruction process from being un-noticeable to being obvious.

Yes I thought you were somewhat optimistic on the cost of not only repairing but also uprating to prevent a re-occurance. From what I've read the norm would be to uprate the liners of bank 2 only, but I guess it depends on how long you intend to hang on to the car. Some would only repair the cylinder that's affected. Really difficult choice and one I think where you need to seek counsel off the guys that are in the know, which is what your doing.

I along with everyone on this forum, I'm sure, are keen to follow your progress, along with the options your offered, and what you take on board to do.

We will assess the situation on the pistons and liners once out of the engine and stripped, where we can do some measuring and more detailed inspection. I think as discussed with Stuey we will remap the ECU to make the cooling fans come in at 85 degrees along with a low temp thermostat

Still going to change all 6 liners, probably just no. 6 piston & new piston rings on others.

I know the pistons are expensive and as RSR have said measurements and examination should clearly indicate if they are reusable bearing in mind they have covered over 100k.
I think you would normally fit new pistons with new liners.
Be surprised if they say they are OK to reuse, but saying that when I stripped down my 964 which had covered 70k they were good and even the rings were in tolerance so you never know.

I assume your plan is to call in the cooling system sooner to reduce the operating engine temperature? Does this have any noticeable downsides on the emissions?

Discussions with several well known engine repair companies has led to some very interesting information. They have advised me that they do not automatically replace the pistons when fitting new liners, only if they are damaged. They also advised they will reuse second hand pistons if they are in better condition. Obviously this is to assist in keeping costs down. But a question for me is around the guarantee as this will only cover new components.....

But I will decide on each pistons fate when engine stripped & tolerances checked. This will be the same for the IMS & RMS.