996 GT3 Leakdown test numbers

[northerner]

What's an acceptable cylinder pressure loss on a 996 GT3 engine with over 50k on the clock? 10%?

[kkerr3]

Year 2000 with 74k:

Cyl 1 : 5%; Cyl 2 : 5%; Cyl 3 : 5%; Cyl 4 ; 6%; Cyl 5 : 7%; Cyl 6 : 8%.

[stradman]

Max 9-10% is ok

[dopsonj]

176,000mile 997.1 GT3 - Less than 2.25% across all 6

[dopsonj]

Northerner.... you're not asking this having purchased LJ04 FNL I hope?

[marky911]

I wouldn’t be too worried at 10%.

Mines a 2003 996 GT3. 49k miles but leakdown tested at 45k.
All cylinders sub 5%.

[BertBert]

marky911 said:

I wouldn’t be too worried at 10%.

I wouldn't be happy if they were at 10%

[marky911]

That’s up to you.

[marky911]

So come on Northerner, what car is it? A prospective purchase or one you’ve got? Not that Polar car is it?

Come on, spill the beans.

[northerner]

Yep, I've bought the Polar Silver car.

The leakdown numbers are 10% and below, with a maximum of 4% loss between all cylinders on the same bank. Not sure where the 20% rumour came from but its inaccurate. There have been limited range 2 over revs (82) which occurred over 2000 operating hours ago. The cam dwell data looks ok which indicates no stretch on the cam chain above normal wear & tear.

I've spoken to leading Porsche specialists who confirm there is nothing to worry about with the above data and they would retail the car. The guidance from a Porsche engine builder is that a rebuild is only required when 20%+ cylinder leakage is observed and that 10% and below is totally fine.