Diagnosing faulty coil packs

It took 5 years ... Ever since I bought my 1999 996 C2 manual, I thought that I had forgotten how to do a hill start on a steep hill without using the handbrake. I found I couldn't judge the revs well enough to be able to keep them around 1200 RPMS, or a little above, as I let go of the clutch. If I rev'd out to 2000RPM I could start, but sounded like a loon with launch control..... Then, on Friday, after being finally fed up with being slower than the 986 3.2 Boxsters (even down the straight) at Sydney Motor Sport Park I was taking the car in to get dyno'd. Except this time, for the first time, the car started throwing some errors of misfires on cylinders 2 and 6. The spark plugs had been replaced last year, but the coil packs hadn't been done during my ownership of 5+ years, and from what I was told, looked like they were older still, we replaced all the coil packs! We suspect that the heavy rain together with the old coil packs finally allowed us to see an issue! My hill start problem is now solved, and I suspect we have found what I felt to be the missing performance. The car now also seems to go better in the low RPM ranges - and I suspect this may continue all the way through the rev range, although not as obvious. Unfortunately we didn't dyno the car before the change so I will need to wait to the next track day to see the real improvement, however the plan is next week to throw it, and a friends 986 on the dyno and see how they compare. Now, the last thing to fix (which is now new) is the vibrating passenger seat at idle - no issue when the A/C is on, but since the coils change, the car is idling a little rougher when at 800 RPMs - It feels okay, so not an "obvious" problem - however the shaking passenger seat clearly indicates there is an issue. How are you ment to diagnose a slowly deteriorating coil pack?! It never threw any errors over the years?!

Must be nice to have that finally found and sorted!

How does the car go at SMSP regarding turn one / two and oil pressure?

My engine hasn't blown yet! and I'll be honest, the last thing on those two corners is looking at is the oil pressure! I am currently still on Michelin PS2N and standard suspension, so I hope that oil pressure won't be too much of an issue. I have been thinking about upgrading the oil pan, FVD vs X51 vs the new Ultimate integrated dry sump, but not sure I need it yet - as my times were really not great - 2:01 was my best time on the GP circuit - I am hoping that the replaced coil packs will drop that significantly. here the advertising for the UIDS: https://lnengineering.com/uids-ultimate-integrated-dry-sump-for-porsche-911-996-and-997-models/ PS: My understanding is that it is the long right hand corners, together with sticky tyres and high oil temps that are issues for the M96 engine. Please correct me if I have missed something.

"long right hand corners, together with sticky tyres and high oil temps that are issues for the M96 engine" Correct Andrew. Longish RHander a few laps at Haunted Hills in my 2000 Boxster S with PS2's... developed a ticking sound immediately after. Fitzy's fixed that and we put an X51 baffle / Deep sump kit on and it never happened again.

@Troubleshooter - Is the boxster engine not installed the otherway around? Would that make the issues for the boxsters the other direction? Now I am just confused... Having said that, I was hoping I would be safe with PS2s with standard suspension, so I am not really able to pull too many "G"s.... And yep, am looking at some sump alternatives, however have been avoiding a deeper sump as the sump is already very low, and in a 996, the engine is at the back....

I was getting pressure drops on the 'old road' and Jenolan caves road (and a number of other roads in the area) I've installed X51 from FVD and changed the 996 swirl pots to the 997 returns.  I've also got Ultimate AOS ready to go in.  I didn't do the UIDS as it would have been 6K (including sump plate) and I take the Porker down dirt roads / country roads so I didn't want the arse exposed. But I'm hoping with PS4S, FVD X51, UAOS and run 1.5L more oil and Motul 300V 5W-50 should suffice. Turn 1 and 2 worry me the most. I'm not sure what I'd pull in the Porker but my best is 1.55 in a Hyundai i30N on PS4S on a 42 degree day. The concern is, for 996, long left handers with the added bonus of any sort of trail braking.  The oil ends up near cylinder six (which is behind the driver up against the firewall).  There's no scavenge pump there.  The 'true' X51 pack added a second piggy backed scavenge pump that had a pickup up in the head around cylinder 6. Martin Hill does a good job of explaining it. The issue is further exacerbated by the 'pretend' dry sump by calling it an integrated dry sump. Pulling 1G the oil can stack at 45 degree angle and run the risk of sucking cavitated oil or worse no oil. Then you have the overly efficient oil pump pumping 30L per min (as I've read) and the two scavenge pumps in the heads unable to return at the same speed with 40 oil.  So Hartech UK and Slakker Dev both recommend 50 or 60 weight oils.  I can provide a chat.  This is what I went off.

Confused myself for a minute, didn't even know the Boxster engine is arse about duh! Anyways, probably a good idea for the deep sump and baffle etc

Thanks for all the comments... When I started my 996 journey, the issue was IMS, but the longer I have the car, this has now turned into oil starvation worries. And worry primarily as a engine rebuild will financially write off the car... Maybe its time to buy an old MX5 for the track.... Or KSwap the 996? 😄

I bought blind as well. Oil starvation is solvable.  It just needs some $.   Ultimate AOS (because the facotry AOS or even the Motorsport AOS can be overwhelmed and risk a hydro lock), either the Ultimate IDS from the same guy that does the Ultimate AOS or Hartech's deep sump with windage tray. Brandon C Clarke (Slakker Dev and the US version of Hartech UK) says the X51 style from FVD is good for non sticky tyres...  I'll find out soon enough. Rennlist.com is very good resource.  What I know now this is what I'd do for anyone running M9X6 engines. UAOS - Allows you to run at least 1L more (1.5L if you're a 996.2 as they dropped the oil level to reduce the hydrolock risk) Replace water pump with genuine only - replace 4-5 years Engine oil with high moly content (works well with lokasil bores)  I use Motul 300V 5W-50 and the oil analysis I'm getting back is great increase from ?W-40 to ?W-50 oil baffled sump of some description Low temp thermostat don't warm up engine. Start and drive. Keep below 3000 until warm If you're going to track - 3rd radiator (what I'll do is replace current radiators with PWR - I don't want the change in the look) If you plan to track hard then ?W-60 oil IMS of some description. if I had my time again I'd go the EFS route and R&R at each clutch change and not the LN Engineering 'solution' for no other reason but I don't like the external oil line