911(996) 3.6

[jvr]

Hi chaps
Read all the forums and i,m looking at getting a 996 circa 2002/2003.What I don't see is that if the 3.6 is more robust than the 3.4.Is there any evidence that the 3.6 is any better or has it roughly the same issues.My eyes are wide open as previously owning 4 TVRs but the prospect of a possible 6-8 grand rebuild is not great.
If it is no better than the 3.4 then I may have to look else where
Cheers
P

[911p]

It's more reliable than the 3.4 lump, but they both have different issues really. With the 3.4 the main risk is an IMS failure, with a 3.6 it's bore scoring you need to worry about. Get one with a Hartech rebuild and you'll have nothing to worry about. Alternatively you could buy a higher mileage one on the cheap and get a Hartech rebuild as a preventative measure (around £5k).

[nick997]

My take on the Hartech reports is that there's not much difference between the two engines, both suffer IMS and bores going oval. Bore scoring is a problem on 997 motors where the head gaskets are common for each side of the engine resulting in hotter cylinders. This wasn't an issue on 996 which had differerent gaskets each side to control coolant flow.

IMS is potentially preventable by changing at a reasonable costs, oval bores also can be addressed but at a much higher cost.

[jvr]

Cheers
So still a risk,but ultimately a small potential
P

[s_mcneil]

Think you (911p) need to re-read the hartech guides. The 3.4 has better cooling channel design than the 3.6 so is less likely to bore score on the later cylinders. All the info is there if you have time to read or search. Bearing and D-chunk can happen to either so there is no fail safe predictor. Both are still amazing cars for the money and I loved mine even with scoring and subsequent repair bill...