997 misfire - how easy/difficult to change coil packs?

[Gixer968CS]

Hi All, I have a misfire on my 997.1 (3.8 C2S) and so suspect coil packs. I thought I may have a crack at changing these myself as it's a pretty hefty labour charge at a specialist. I've had a look at the job - rear bumper cover off, exhaust mufflers off, heat shields out etc and although it looks time consuming it doesn't seem particularly difficult. I'm reasonably competent at car maintenance and quite fancy having a tinker at this but am I overlooking anything, pitfalls, stuff that might catch me out. I'll have the car on stands for the work, which looks like it'll be ok and will change the spark plugs while I'm in there.

Any tips for me, am I overlooking anything. Quite mad etc?

Edited by Gixer968CS on Wednesday 7th January 15:18

[accountanother]

If all is straight/clean, its relatively straightforward, if its all rusty, good luck, you could find yourself cutting and replacing more than you bargained for.

[Gixer968CS]

accountanother said:

If all is straight/clean, its relatively straightforward, if its all rusty, good luck, you could find yourself cutting and replacing more than you bargained for.

Thanks for that, presumably potential problem areas are exhaust mufflers and heat shields?? I guess, even if I took it to a specialist if these items are corroded so that they can't be removed then they'd need to be replaced anyway or would they be able to use tricks that I can't?

[16610LV]

Maybe also ask/search on the '911uk' Porsche 997 sub-forum. Loads of great information there.

[-r-]

I've not yet done mine (parts sat there waiting for the spring), however I have done it on a 996 & you don't need to take the bumper / exhaust off (I'm led to believe the same is true for the 997), however these two tools were essential to getting the plugs out (the coil packs come out without any particular trouble, the rear most are just a bit awkward, from memory an 8mm spanner will undo the etorx bolts):

https://www.amazon.co.uk/Laser-3520-Ratchet-Swivel...

https://amzn.eu/d/8PQVdyQ

The flexibility the ratchet offers combined with some extension bars makes the two awkward plugs at the back achievable. (That ratchet has really earned it's keep in the year I've had it, should have bought one years ago)

I will add, I've replaced the silencers on my 997.1 c2s last year, if yours haven't been off you are in for a fight, the clamps will be entirely corroded and need cutting off, and the three bolts holding the silencer to the subframe bracket if anything like mine will need a die grinder on them and replacing, there was no chance of undoing them.

[maz8062]

Not an easy job. If you don't have a lift, the best approach is to remove the rear bumper, the heat shield, and the muffler. You'll also need one of those extended spark plug removal tools if you're swapping plugs at the same time.

[FriedMarsBar]

As others have said the rusty nuts and bolts are your biggest issue. A cheap screwfix powerfile is hadny for getting into tight space and grinding off the bolt/nut, also cobalt drill bits are handy. On my .2 I took the enire exhaust system, almost in one piece, then ground/drilled etc until it came apart. Don't bother trying release fluid they'll almost certainly be too far gone unless they've been replaced in the last few years. If you do take it apart buy a load of 8mm stainless nuts/bolts and washers.

[Gixer968CS]

Thanks for all the replies guys, I really appreciate it. I thought that getting the exhaust apart may be an issue but those 3 bolts that attach the silencers to the engine mount look tricky to deal with with the car on stands on the drive at home if they're going to get stuck. So, I called my local indy for a quote and they said £510 + vat for all parts and labour. That seems pretty reasonable given that the plugs and coils packs themselves are c£200+vat. Looks like they reckon 2+ hours labour. So, I'm going with that and fully expect the bill to grow for new exhaust clamps and probably replace rusted heat shields, which I would have to replace anyway.

For the sake of £300 I thought I'd just pay to get it done and avoid any dramas as I muddle through but thanks again for the advice you certainly helped me decide what to do.