etwd

Can a cracked coil pack (hairline around screw hole) cause a mis-fire, without a CEL?

Shark Attack

I dont think anyone can answer this question for certain. However the good news is a coil is only about 50 bucks and if yours is cracked may not be a bad idea to replace it anyway..

ROK

I've read somewhere that the 997 coil packs are a great replacement as they're better designed and are compatible with the M96 engines.

1999Porsche911

If you do not have a misfire code, you probably are not misfiring. In general, any misfire will throw a code, regardless of the cause.

etwd

Thanks!

jumper5836

Your joking right. Because I've seen 2 year old 997s having had to replace the coil packs all ready. Mine lasted 6 years before they needed to be replaced.

As well my 04 Cayenne had all the coils go on them in 2 years as well. The new coil packs in my opinion are crap.

1999Porsche911

I have 12 years on my 99 C2 factory coil packs. This is another component that many people replace when not necessary, just like the MAF.

ROK

They're better made. Believe it or not, Porsche actually improved on the design.

What's clear is in this forum alone, you'll find numerous coilpack issue threads. Anecdotal v. anecdotal.

jumper5836

hmm I tend to believe they just found a cheaper less expensive coil. But yes it is an improved design. Improvement being money saved in their pocket.

MechanicalEng

My car (996TT) was missfiring and NOT trowing a CELs, we knew it was missfiring because PIWIS showed missfires on 5 out of 6 cylinders, all the coils were cracked. We replaced all of them with the new 997TT coils and the car now runs smooth and it doesnt missfire anymore.

ROK

I guess I just don't have as jaded a view into Porsche's development efforts as you do, but I believe the MK2 is better built than the MK1 and the 997 to the 996.

There's really no factual basis to our little debate so you guys reading up on this do as you will. Stick with the 996 coil packs that have cracked or consider replacing them with the 997. You can't go wrong with either, but I chose to go with the newer design.

jumper5836

I did the same but on my C4S with 996 coils packs, doesn't misfire anymore as well, but at least they will last more the 2 years.
My Cayenne is all ready running rough with the new coils. Just plain crap.


Here is some more 997 improvement, look at that standard header.
and the upgraded one


which looks like the 996 standard header



Then imagine all the plastic pipes and pieces the improved the 997 on with. Cracking and failing in 10 years from now with hefty repair bills. Just like my Cayenne losing all its coolant from cracked pipes which now have been changed from plastic to aluminum. All Cayenne that were fitted with the plastic ones will crack. just a matter of time.
Saving money comes before building long lasting autos now.

ROK

The M96 and M97 are largely similar. Wonderful engines I think we would all agree here.

So why mess with something that works? The beauty about the 911 is its timeless design and what I find very cool about Porsche engineering are the results that you realize when you drive the thing. It's far from flashy, but full of substance. Check out the PSE mufflers. Butt ugly, but the sound they make is wonderful!

The 996 is over a decade old now. Issues will come up. Knock on steel, but my 996 has been supremely reliable. I do understand some owners have had different experiences so, again, YMMV as as each owner has different modes of level of care and attention put into their vehicles.

Admittedly, my original coil packs looked fine when my indy swapped them out with the 997 versions. No problems either way. I got it all done as part of a service interval and the cost was the same. Indy does work on Porsche motorsport cars and I followed his recommendation. He showed me the reasons why in the design. I believe him.

I know nothing about the Cayenne/Touraeg so can't*won't comment there.

mtl911sc

Which raises a good point - all public companies are under relentless pressure from shareholders to increase profitability by increasing sales, reducing costs, or preferably both. Porsche is no exception.

You see it all the time...products which in the past were of impeccable quality gradually become less & less so, to the point where problems creep in...just look at Toyota - their issues didn't happen overnight. And cars are certainly not the only example.

So IMHO newer does not necessarily mean better when it comes to Porsche parts. Improved design perhaps, but can also be achieved at the expense of quality. If that wasn't the case we'd likely be paying more & more for new cars with every passing year.

I'll leave the podium to someone else now...

ROK

You guys remind me of the 993 guys now