996-997 wet-sump engine reliability: enter your stats here!

996-997 wet-sump engine reliability: enter your stats here!



214 posts

92 months

Saturday 21st December 2013
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2001 996.1 3.4 C4, from new, engine failed @ ~32000 miles (gear box also died 2 weeks after new!)


13 posts

86 months

Thursday 22nd May 2014
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HI I am in a bit of a dilemma and asking around for help
Here is the short story
my engine number is 66108196 and Vin car is WPOZZZ99Z1S602589 my cylinder diameter is 96 MM which clearly states is a 3.4
the one i bought on ebay is not very clear but reads 04032090 maybe but vin WPOCA29971S651915 ,I manage to get the Heads PN 996104227OR which also clearly states is a 3.4
both written on the heads Vario CAM F1 Head old and new engine
BUt the only difference is the harness for the engine
Mine original engine has 6 wires going in to the throttle
The one I bought has 3 wires in to the throttle (C4 Coupe manual Originally that I was told by seller same as tipronic interchangable )
here details stated when I bough it on ebay
01 Porsche C4 AWD 911 Carrera 4 996 ENGINE MOTOR Manual M96.04 3.4 M96/04 3.4L 76k
You are purchasing the used 3.4L M96.04 Engine -removed from a 2001 Porsche 911 Carrera 4 Convertible 6 Speed Manual AWD(All Wheel Drive) 3.4 DOHC 24V VIN# WPOCA29971S651915 with ONLY 76k MILES

This are my thoughts something along the way is wrong
the ebay engine is in my car, it turn but no fire
maybe the engine that is now in my car the ebay one needs an adjustment to start I put my old wire harness in the ebay engine to fit My throttle but I have missing cables

tiptronic probably needs more sensors then manual
Is there something i am missing
Maybe in the ebay engine which is manual I have to fit the older heads?
the car has no battery for 4 months too

going nuts can any one help?


123 posts

109 months

Saturday 31st May 2014
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For your survey ....

My 2000 996 C4 has the 3.4 engine.
It has completed 121,000 miles - at least 50k with myself at the wheel

No record of any engine repairs and it's still running smoothly

Chris Stott

8,570 posts

164 months

Wednesday 11th June 2014
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Update for mine...

2000, 3.4, manual

Now at 150k miles, 93k in the last 7 years, still runs sweetly.


1,910 posts

184 months

Thursday 12th June 2014
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Hopefully the huge differences in mileages covered by various cars explains how difficult it can be for specialists like us to advise on likely lifespans and internal conditions.

We have had engine failures under 20K and others nearer 150K and the quality of some internal components, the way it has been driven, the quality of maintenance etc must all contribute to the outcome although of all these I think the statistics mean there must be a random small number that simply will fail despite the best maintenance and driver care possible and that in some cases there was nothing anyone could do to avoid it.

In other cases (those that fail nearer 60 to 80K) I guess one of the several owners probably didn't apply the same degree of warm up or maintenance care as others while some manage to plod on to very high mileages but probably have never been abused.

It is worth pointing out that quite a lot of high mileage cars have a different engine number to the original which was replaced.



1,795 posts

176 months

Saturday 14th June 2014
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We have had engine failures under 20K and others nearer 150K


At 150k it could be argued that the engine has come to the end of its expected lifespan.


1,910 posts

184 months

Sunday 15th June 2014
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Yes it could but not if you were discussing a 944, 968, 3.0 911SC, 3.2 Carrera 964 or 993 - for example.


Chris Stott

8,570 posts

164 months

Monday 28th July 2014
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911wise said:
At 150k it could be argued that the engine has come to the end of its expected lifespan.
I hope not, as I expect to use mine for years to come!


24 posts

119 months

Tuesday 29th July 2014
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Baz said "It is worth pointing out that quite a lot of high mileage cars have a different engine number to the original which was replaced."

Does this mean that it's most likely that you would need to do a rebuild?

Was the cause of this IMS or other mode of failures such as D-chunking, scored bores?


13 posts

178 months

Tuesday 14th October 2014
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128,000 miles in 1998 996 C2, owned last 7 years and 65,000 miles by myself and used as my only car.

Apart from a blocked fuel tank breather, routine servicing only has been required (and hoping things stay that way!)


19 posts

123 months

Thursday 16th October 2014
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128K miles / 70K by me in last 8 years - 1998 Carrera 2 tiptronic with GT3 bodykit

Total engine rebuild by hartech 15k miles ago - cylinder fault usual thing on first car out the factory. - Expensive cost at 7k
Gearbox rebuild at 100k - seemed ok, had the oil changed then the thing fell apart - 2.5K

Just about to move the car on as needs Torque convertor replacing, wheels redoing and bodywork tidying up so if anyone looking for a project that has a rebuilt hartech engine, gearbox and needs about 2.5k spending to make it beautiful again let me know, looking for 7k.

All receipts for every piece of work done to it which in total is over 30K-40K.

Full GT3 bodykit factory fitted with wheels, red interior, original phone still in there !!!


18 posts

232 months

Wednesday 5th November 2014
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996 c4, 2001: 96k. Original engine. No internal work. RMS, clutch and IMS bearing just replaced by me. Bearing was in perfect condition. Apart from the elective work, I've only paid for consumables since owning it. These are lovely, sweet cars.

Sine Metu

301 posts

93 months

Saturday 29th November 2014
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1998 c2. 80k miles on it. Originally a Uk car, now in South Africa. So it's been on the road and off the road at times. No special treatment. Runs like a dream as it always did and laughs AT&T the official Porsche performance numbers. It's far quicker?


374 posts

82 months

Friday 13th March 2015
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your expert knowledge is sought here please, been looking at 996's and 997's and am unsure which to go for, i only do about 4000 miles a year with maybe 6 miles a week and 3-4 long runs from London to Scotland every year.

i was looking at the convertible carrera that 911 virgin had but someone has a deposit on it, now have spotted this 997


now that is right at the very top of my budget, with it having a rebulid would that give me peice of mind,??

the other one was a bargain 13995 in my eyes and i would have spare money to put away for any mishaps etc.

your advice is appreciated



6,065 posts

139 months

Friday 13th March 2015
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The ad suggests that they are undertaking the rebuild themselves. If so, I would want to know if they are fitting OE liners and pistons and hown many cylinders they are doing. If they are refitting OE parts, then the problem could arise again in the future. Likewise if they are not replacing all three cylinders on the r/h bank.


699 posts

227 months

Monday 8th June 2015
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March '98 996 C2 3.4 manual

131k on the clock with a Hartech top end rebuild at 85k due to broken valve spring

Have only owned it for 2 months but have done 500 miles in that time & generally explored the full rev range, after gently warming it up first. Only use it for proper runs, as opposed to short trips.

Had full new MO30 suspension replacement in last 18 months & mechanically is very sweet & responsive to drive. Have changed gearbox oil & will be flushing & replacing the brake fluid with some decent stuff.

Interior in lovely condition & after careful cleaning the leather has gone back to a lovely supple matt finish.

Love the analogue feel of the car, much like the earlier 911s - mine has cable throttle & doesn't even have ESP, just a LSD!

So much 911 for the money & such a rewarding car to drive, belying its 17yrs


1,910 posts

184 months

Tuesday 21st July 2015
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Just to correct a slight inaccuracy, these engines don't have OE liners - the Lokasil is cast into the cylinder block.

You can replace these with new ones but it is not cheap and the combination of Lokasil and the newer plastic coated pistons is a solution now superseded by Porsche themselves in the Gen 2 engines to improve lifespan.

You can also fit a new bottom end (but with the self same Lokasil/plastic coated piston combination and likely outcome although we can improve the situation if the customer prefers by fitting support rings to convert to a closed deck and increase coolant flow).

Or you can have our Nikasil alloy cylinders fitted that also convert the engine to a closed deck design (as also adopted in the Gen 2 engines that also have increased cylinder block coolant flow - another modification we can carry out to either Porsche cylinder blocks, Porsche bottom ends and of course our own Nikasil cylinder conversions).

overall there has never been anything found better than a closed deck Nikasil alloy cylinder in either Porsche's history (or most other high performance engines).



15 posts

65 months

Wednesday 24th August 2016
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For the survey:

2000 996C2 3.4 manual, currently with 71k miles. Owned for nearly 12 years and 32k miles. No engine work - routine maintenance only, with oil changes every 18-24 months and 3-5k miles. Nothing really ever gone wrong other than wear items - will shortly need 3rd new set of rear tyres, still on 1st set of replacement fronts, has had front and rear brake rotors and pads, oil and brake fluid. Clutch / gearbox etc still fine. Occasional trouble with O2 sensor - I imported car from US and it seems slightly sensitive to the different fuel here in NZ, with the check engine light occasionally coming on and off.

Love it!


109 posts

158 months

Thursday 15th September 2016
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For the survey: 02 C2 3.6 manual. 72k miles, no engine work. No oil leaks. Always serviced on the dot. Does need new back boxes though smile


10,756 posts

136 months

Thursday 15th September 2016
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AlasdairB10 said:
For the survey: 02 C2 3.6 manual. 72k miles, no engine work. No oil leaks. Always serviced on the dot. Does need new back boxes though smile
I can highly recommend Cargraphic smile