Hello All,
Firstly I have now had my 968cs back on the road after 2 and a half years off the road, parked in my parents garage in Surrey!
Why? I hear you ask?...yep..the dreaded Camshaft issue! In 2001 (screen wobbles and goes hazy in a sccoby doo type flash back effect) my car developed symptoms of noisy "rattling" coming from the top of the engine.
POINT OF NOTE: First sign of any "rattling" or metallic sounds coming from the engine....get someone who is experienced in 968's to take the head off and have a look!
Anyway back to story:
My car originally came from Stratstones many moons ago and when I bought the car in 1996, the guys at RUF GB then became the service chaps for the car! Well I would like to say my experiences were all good there, but unfortunately they were not!
We did the whole gear pinion thing, back and forth, diff "clunk/slap" and eventually after many months, I decided to put a Quaife Diff in the car to replace the Torsen unit and it really did transform power delivery.
We then made a few mods to the engine and during a few issues the camshafts were replaced, along with chain! This was probably at around 50,000 miles ish! Just before RUF closed its doors in Weybridge, I had the straight through exhaust system made, so we now run a pipe straight from the block to a TechArt back box! Very noisy, very quick and huge fun!!!
Unfortunately through job change situations, I then had to use the 968 on a daily basis, which in a CS can be hard work as its on the MO30 Sports kit, track setup half cage and harnesses! Not ideal for a daily commuter, especially not with the Quaife diff!
Well come 2001, said noisy sounds started coming from the engine and a trip to GT One in Chertsey, Surrey, was required. Craig and Pete who were ex-RUF and probably the two guys I trusted the most, with excellent experience and honesty and they tell it as they see it, unfortunately they had to work with other people previously not quite of the same calibre.
Anyway, when they took off the head of the engine! Hey presto....about 8 teeth left on one camshaft and about 9 teeth left on the other camshaft!!! I was about 1 month to a couple of weeks from the chain flying off the teeth and the engine trying to explode into many different directions!
However, suspicion lay with the tensioner device itself! Now, as some of you many or may not know, this was the first time "Vario Cam" technology was used and in laymens speak (my kinda language) The Tensioner sits between the two camshafts, it adjusts up and down on a thin chain which connects the two camshafts, inlet and exhaust! The more throttle you use, the more the tensioner goes up or down, thus opening or closing the profile of the camshafts to give more or less power! Hence the performance gain on this engine over previous 944 lumps!
Now Porsche official pricing on Camshafts is around £500 each, plus the tensioner itself is around £800 (the one in the new 911 is only about £100...Grrrr) The chain is about £20, etc etc etc etc.
All in all, when all put together with labour its well over £2000!!! Unfortunately as I had started my own business, there were just more important things to be spending that money on! Hence she was parked!!! A very sad day I have to add!
Anyway....I decided to investigate this whole camshaft issue with head of engineering at Porsche GB in Reading and paid them a visit last year at around September time. I spoke with a guy there at length about the whole Camshaft, teeth issue! His name was Paul I believe, but knew 968's inside out and back to front. (unfortunately he has since left and not sure where he has gone)
The issue is one of design and metal used! The
concept of Vario Cam is sound and it delivers fantastic perfermance,
however, Porsche now recognise (possibly never officially) that the
use of a single chain, no more than a centimetre in width, to connect
the two camshafts, was probably not wise! Due to the constant power
load and tensioning of the chain, it really needed to be double the
strength and possibly even two chains instead of one, to even the load.
More importantly, he said that there was a suspicion that the metal
used for the camshafts was also not durable enough, as it seems all
968 camshafts seem to lose teeth at between 50,000 and 90,000 miles,
the Club Sports it seems slightly quicker than the Coupe's, and Cabs
for some reason.
What he did say however, is that there have been very few if any, actual
failures of the tensioner itself, but you do have to do is replace the
two plastic pads that sit under the chain, as the chain cuts into the
pads and may also attribute to the chain not pulling freely on the teeth
of the camshaft!
Anyway............gasp...
As of the New Year I put the Car into GT One and as of 3 weeks ago...I am now the very very happy owner of a damn fine 968CS!
I bought the Cams from Euro Car Parts at a price
of £296 each ex VAT, which was a great deal, on the proviso that
they must be genuine articles! They arrrived and true enough they were!
We bought new slipper pads for the tensioner, a new chain, varios gaskets,
the valve seats and caps were all still good, replaced all fluids, diff,
gearbox, oil, everything, along with a new K&N Air Filter which
has really helped the 90mph plus region, with the engine really breathing
much better! Suffice to say that at a venue undisclosed, the car was
pulling 140mph in 5th before changing to 6th past 150mph where it became
lighter on the tyres could definitely use some more downforce! Test
completed!!!!!
It really is a very quick car now, sounds incredible and as a pure drivers
car it cannot be touched! I have rally driven a number of different
cars from Group N Clio Williams to Mitsu's and Scoobs and whilst these
cars are very quick, there are so many aides to get you out of trouble,
traction this.....Yaw control that...blah blah...blah, which is why
you now have hugely inexperienced drivers, racing around in "souped"
up Japanese mobiles, having very large accidents.
All in, I have spent about £2200 getting it back on the road and worth every penny!!!!!
Andrew Frankle of Autocar still rates the 968CS as one of the finest drivers cars of all time and its very interesting to see that the new Aston Martin V8 Vantage due out in 2005 and set to rival the 911, is also set up in exactly the same configuration as the 968! Engine in the front, Diff, gearbox and drive in the back...aka 50/50 weight split.
So...thats a brief service history of the joys and perils of a 968, but on a day like this....blue skies and sunshine, there really is nothing like it! Roll on the Summer!
I am based now is West Sussex, so if you see a White 968 CS burbling around! Throw us a wave!
Sorry for the long post, but thought you guys and gals maybe interested!
Best Regards
NeilC