Z4C to 911 possabilty
- Thread starter monkadill
- Start date
Some things that people don't realise on the 996/997 and 986/987 engines is that they have oil jets on the crank webs which spray oil into the lower bores, these jets only open at above 1.8bar oil pressure so when hot at tick over they are just on the edge of opening and oil flow is limited by the slow speed of the pump, the cooling jacket passages around the rear cylinders slow running etc is the main cause, of course slow running also means slow coolant flow which exacerbates the cooling problem, the engines will pull easily from 1,000rpm without distress but low flows of oil and coolant! Keeping revs above 2,000rpm and changing down for the hills helps of course but the engines are built for faster speeds and so heavily driven engines last better than those who drive forever at low revs which wrecks the low speed low mileage engines. I ran a 987 gen 1 Cayman S 3.4 to 88,000miles without problems that model had the latest design of RMS and the last iteration of the IMS. Note that the IMS is not oil fed unless a modified unit is installed and even most of them are grease packed sealed units, a ceramic bearing being the favoured replacement, in the 987/997 gen 1 range the general consensus is that each of the problems is about 1% and the low mileage little used cars are the main problem. The 997/987 gen 2 had the IMS designed out of it and received DFI to improve emissions. Bore scoring is still possible if they are run at low speeds for the same reason although oil pressure control is said to be electronically managed, whether that means an electric pump to maintain pressure and flow at low speeds I can't say but there are even less problems than the overstated bore scoring propagated on the internet where one instance can be repeated hundreds of times!
Our 2000 996 C4 has over 100k miles on it. Needed an RMS at about 95k miles so had the IMS done at the same time. IMS didn't need replacing, no signs of a problem, but since we were in there, we had it done.
These things live live longest when thrashed, not nannies or laboured. It's a mechanical beast, treat it with some mechanical respect and it'll be fine. Drive it how it should be driven and all will be well
These things live live longest when thrashed, not nannies or laboured. It's a mechanical beast, treat it with some mechanical respect and it'll be fine. Drive it how it should be driven and all will be well
