medent

My car is a 2000 996 C4 Cab and it doesn't feel as spirited as my wife's 2000 996 C2 Cab. Mine has100K miles and hers has 65K miles. Any possibility it might be the coil-packs and/or the sparkplugs? Any way to test it without removing and replacing them? They are probably originals on the car (there is no record of replacing them). Hate to purchase new coils if they are not required. And wouldn't want to replace just the plugs and have to go back in and replace the coils.
Any advice?

bmo72

I replaced the plugs and coils in my car (99 cab 130k) and did not notice any performance difference. If the plugs have 15k it more miles on them , replace them. If the coils are working, leave them in

sandersd

With 100k just replace coils and plugs and be done with it.

relinuca

If any plug coils were weak or mis-firing, you would be seeing a CEI.

An examination of the spark plugs by an experienced tech would identify any important combustion issues.

I suspect some cause other than the coils and/or plugs, assuming the latter have been changed in a timely manner.

relinuca

medent

It's not like a night and day difference. But her car feels somewhat lighter and more peppy. Maybe just the C2 vs C4?
But probably a good time to replace the plugs anyway.

STAGGERWING

Spark plug reading is one of the easiest indications of motor performance & identification ain't no rocket science , regardless if its a Rotax, Briggs & Stratton or a 996.
Black --poor rings , compression , spark , timing , rich mixture , AOS , running at too low a temp.
White--she's running too hot , timing , wrong plug , engine will ping or knock , burnt valves will happen.
Plugs should be a light to medium brown color indicating efficient combustion as well as exhaust outlet --however you have the cat converter to consider w/ exhaust pipe

Bob

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01 C4

31 Ford cp chp & ch, 302/350

40 ******, 302/350

38 Ford cp, 327/350

57 Belair

62 356B --long ago

geetee

i was going to say...c2 vs c4

Imo000

You are wasting hp with the awd. That's why your AWD is slower than the wife's C2. Bottom line is you have a slower car.

Changing the plugs if over 15K mile is crazytalk. Waaaaay too early.

sjg1138

I drove a 2000 C2 Cab and a C4 Cab back to back and was surprised at how heavy the steering and sluggish the C4 felt compared to the C2. The C2 just felt more nimble.

sandersd

Absolutely! I did exactly the same and felt the same afterward. The C4 wallowed through the turns in comparison - that's how it felt to me.

sjg1138

I think the C2 cab is already heavier than a non-cab C2. Add the additional weight of the C4 and maybe that explains it. I really noticed the upfront weight in the steering. Looks like it is only 120 lbs but maybe that is enough.

"However, the advantage to front/rear weight distribution isn't significant, because the entire system adds a mere 120 pounds to the Carrera 4's curb weight." - http://www.edmunds.com/porsche/911/2000/road-test.html