Porsche Enthusiasts Club Forum

hi all ... I'm new at this, so go easy on me please.
I'm looking to buy a 2007 (ish) Boxster & had my heart set on a 3.4S. I've driven several & it ticks all the boxes!
I've just been told that the 2.7 is a much better option as the 3.4 can have problems with con-rod shells? Is there any truth in this? Also, is there much noticeable difference in performance? Thanks.

OK there are various problems with the M96 engine as is used in this era of Boxsters, Caymans & 911s
Very early 2.5 engines suffered other various issues, but the general issues are:

RMS, Rear Main Seals these weep & very rarely cause a major issue. When the gearbox is dropped for a clutch change then the seal can be changed.

Bore scoring: this is where the plated alloy bores suffer scuffing & suffer excessive oil consumption. Normally bores 4, 5 & 6 which is the hotter side.
Various ways of reducing this risk. A. Drive it harder, cars that are tracked & raced don't tend to suffer this. B. run a heavier oil than Porsche spec 5W/30 Hartech recommend 10W/60 & I run 5w/50 Comma Motorsport which is also a lower API spec than the current oils used. C. Don't let the engine lug in low revs/low gears. Tiptronics are bad for this as they pull away in 2nd gear unless in manual mode.

IMS (Intermediate Shaft) Bearing: Crap design by Porsche, the flywheel end of the intermediate shaft is supported on a skinny bolt & by a bearing which is shielded. It starts off grease filled & after a while debris gets trapped behind the shields & eventually the bearing collapses. Or the bolt breaks. The bearing can be replaced whilst the RMS is being done, although some do not recommend this, others recommend a complete strip down to replace. If the bearing lets go then the damage can be immense. At the very least all the meal debris goes through the engine & needs clearing out. Running the heavier oil as detailed above helps.

Bore distortion: This is at its worst the bigger the engine. At high miles the unsupported cylinders distort & again massive oil consumption is the outcome.

Thanks Jim ... much appreciated!

Whereabouts do you live ?

There's a thread or two on here somewhere about my Cayman engine saga (M96) that might be worth a read. Before purchase check the contents of the oil filter - for debris (as Jim says). If clear / clean you at least you know IMSs's doom is not imminent. It is rare though remember. Also, check the coolant - it should be clear, if it's muddy brown run away! Great cars though, oh yeah - just need to be careful on choice. I bought a 2.7 too and love it - and tis less risky all round. Good luck.