Has your 996 or 997 engine had a major rebuild?

Has your 996 or 997 engine had a major rebuild?

Poll: Has your 996 or 997 engine had a major rebuild?

Total Members Polled: 819

No: 465
Yes because of the IMS: 62
Yes because of scored bores: 80
Haven't bought one because of known faults: 178
Yes because of D Chunk failure: 9
Re-built prior to purchase, not sure why?: 38
Author
Discussion

Chris Stott

8,567 posts

164 months

Thursday 3rd June
quotequote all
30% failure rate?? laugh

There are loads of owners on the ‘what’s an early 996?’ thread, many are long term owners running cars with well over 100k miles and I don’t think there are ajj no t that have had engine rebuilds - unless the owners specifically looked for cars to buy with rebuilt engines.

Stop exaggerating.

hartech

1,910 posts

184 months

Sunday 13th June
quotequote all
Perhaps it is time for some sensible reflections. The failures of these engines are not as easily predictable because they rely on the quality and distribution of the silicon particles in the Lokasil preforms and how they orientated themselves in the castings when the high pressure molten aluminium was compressed at 100 bar and the bonding of the piston coatings (the amazing variations of which can be seen in photos in our reports on bore scoring free from admin@hartech.org)

Then engines in drivers cars who never apply high torque will generally get longer life (because the oil is usually cooler and thicker and the thrust loads squashing the piston against the cylinder wall with a piece of silicon trapped between it are lower) and those who use relatively higher revs (but not combined with full throttle) maintain better cylinder wall oil film thicknesses (so Tiptronics suffer slightly more).

Continual high revs may well reduce bore scoring but reduce big end shell bearing life.

We have had failures from as little as 15K and as high as 170K but at the high end they all have piston coating loss, worn crankshaft shells etc and many unable to rebuild without more new parts.

Statistically whether it is 10% or 30% doesn't change the fact that they are on average capable of less miles than their 944/968 counterparts or their 911 earlier variants. it also doesn't change the facts that most will eventually require a rebuild and at least there are now good options either when that happens or beforehand.

Whenever you talk statistics you inevitably get someone who didn't fit into the main stream masses and gets upset because "THEIR CAR DIDN@T LAST THAT LONG OR LASTED MUCH LONGER" and I think it might just be worthwhile reflecting on the fact that these statistics are extremely helpful when enabling prospective owners to assess risks and perhaps more importantly specialists to invest in the right level of and amount of facilities to cater for them.

We assessed the first engine over 20 years ago and made an engineering decision that sufficient numbers would fail for long enough to justify investing it R & D, technical solutions, manufacturing plant, training skilled and experienced labour, and it has paid off. It too was a risk but statistics still help us direct the growth of the business and are therefore valuable.

Problem is if you make a general statement like "generally men are more into cars than women" you immediately get some angry person telling you that they know a female who is mad about cars etc.

Statistics don't lie but of their very nature they do NOT APPLY TO ALL THINGS NOR EVERBODY OR EVERY CAR.

The best thing is that STATISTICALLY a Hartech re-manufactured standard or increased capacity engine has proven to be a very good option if and when a repair is needed.

Baz

Edited by hartech on Monday 14th June 07:27