Hi all,

A friend in distant (both to me in the UK and to most of you in North America!) New Zealand is having engine problems with his 2010 997.2 Carrera S.

It's at the dealer's at the moment and apparently it's some sort of missing that's only happening on cylinder one (and I mean both one cylinder only and that cylinder being cylinder *number* one).

Apparently it's not any of the usual ignition things like spark plug leads, coil packs etc.

They're wondering if it's not something internal like a valve spring, but they've not found anything yet. I'd like to help by getting a list of things that'd be good to look at while they're in and digging.

Anything sounding familiar for some other unlucky soul? The car has only done around 15k miles.

Thanks very much for any help!

Ben

 

I guess if it's not a problem with the sparkplug or coil packs, that leaves a dud fuel injector or perhaps the variable valve timing actuators.

 

hmm could it be carbon build up, maybe a timing solenoid

 

15k on it ???? the cylinder died of boredom.............what was the result of a compression test ?

 

Varible timing would probably affect the whole bank. Likely a bad hydraulic lifter or injector. less likely is junk on the valves, bad ring, scored cylinder. I'd change the coil and plug just to be sure. Then i'd do a compression/leakdown test. Then i'd probably use a boroscope if one was available.

 

ZING!

 

A compression test of at least the #1 and #2 and #3 cylinders (to ensure the adjacent cyilnder is ok) in fact the entire bank (at least 2 out of 3 anyhow) are ok, and to confirm there is a compression problem I think is called for.

In fact just do a compression test on all the cylinders. Be sure the engine is dead cold. And the engine should be cranked some before any test is done to get the cylinders wet with oil to make sure all have the same benefit in sealing this provides.

If the compression test finds the #1 cylinder down while #2 and #3 are ok that's one thing.

If #1 is way down and #2 and #3 are down compared to the #4, #5, and #6 that's something else.

If just #1 is down a leak down test with a listen at the intake, exhaust and oil filler tube or crankcase hose to detect a leak of air through the intake valves, exhaust valves, or perhaps past the piston/rings and cylinder wall is called for.

What the results of all the above are determines the next step.

If there are any valve leaks it could be just a heavily deposited valve. Perhaps a borescope inspection of the intake ports and the valves could spot this. Or better yet scope the bore with a bright light in the intake port and exhaust port and look for any light in the chamber. This will let you know if any valve is open or just has a poor valve head to valve seat seal.

If the entire bank is low on compression this might be something related to the VarioCam Plus system. This hydraulic (engine oil) system can sometimes (rare but it happens) get contaminated and this can interfere with the variable valve lift feature. Generally all lifters on this bank are replaced when this is suspected.

I could go on.

However, for a proper Porsche shop with access to all the factory manuals misfires and the diagnostic steps to pinpoint the cause are spelled out the shop with access to this should know all of the above and more.

 

Thanks very much for all the helpful (and in some cases funny ) replies, you lot.

I've passed on all of the ideas and with a bit of luck they'll diagnose something that's either nice and easy to fix or that they cover on his behalf - it's not been the most reliable car for him so far.

I'll post back when we know what it was in case it's of interest and helps someone else when they come a-searching.

Regards,
Ben

 

Looking like it might be the injector on number 1. Waiting for Porsche NZ to come back to him about warranty, as apparently all six need to be replaced if this is the problem. $6kish if so. Fingers crossed.

Diagnostics also mentioned valve problems, so it might be that you guys weren't far off the mark with ideas.

I'll post more updates when I get them.

 

Good luck and keep us posted. I think I saw some injectors for sale on the other forum.

 

Seems like a lot of money for 6 injectors and labor (even if they have to pull the engine). Might want to think about an independent service shop if warranty doesn't happen. Good luck.

 

All 6 injectors on a 2010 997.2 sounds like BS! Even previous models have more problems with cylinder and valve train failures than injectors. High pressure fuel pumps fail, even to the point of a campaign. But injectors, and especially all 6 for a single cylinder misfire... I don't see it. Even if something had tainted the fuel system, like say water, we're once again back to multiple cylinders.

 

All six injectors replaced free of charge by Porsche (phew) - car running properly now.

Thanks for your input, everyone. Hopefully this'll be of use to someone else in the future.

 

When the car was exhibiting the missing problem did it show in the piwis? Was there a check engine fault?