galanevans

This doesn't seem possible, but would coil packs start failing at 20k miles? Distributor Caps and Rotors were done 25k miles ago, Coils were swapped out 20k miles ago, and plugs were changed out 7k miles ago at the last valve adjustment. Seems like all should be running smoothly, but lately I'm getting that stutter on the accelerator during the first 2-3 minutes after start up that typically signals a problem in the ignition system.

I was planning to replace all the above at my next service in another 5k miles, but it seems I may not make it that long.

There's enough posts on the typical coil tests to run, but mostly I'm just interested if this lifespan seem right for these components?

Vegas993

There are lots of posts on the later Silver coils not being what they used to be...

Goughary

I had a couple sets go at around that time...

So yes, it's possible. I now convert the cars to run 993 coils, as these seem to be a lot more reliable - but none of us have done 20k miles yet to verify that claim. I'll let you know in a few years!

Someone just needs to produce the old blue coils again. Those things you still see on old vw and 914 and 911, and they are still going!

But the 993 swap is easy. And reversible. So that's what i do now.

A914MAN

I did the 993 coil conversion to my 964. If you are interested I've got a pair of coils and one has only a couple thousand miles to it. I thought I had a coil problem, but it was a plug wire problem.

Peteinjp

One of my silver coils crapped out after a few months! I’m going 993 as well.

Pete

Silvertarga

I have had them bad right out of the box, did the m993 conversion and havent had a problem, seems that the coil terminal on the distributor caps is also a weak spot (Beru or Bosch, not what they used to be) had spark leakage from both brands so I use di electric silicone on the distributor cap fittings..

JasonAndreas

How bad is the carbon buildup on the contacts inside the distributor cap? They probably should have been replaced at the last valve adjustment, 25K miles is really pushing it.

galanevans

Coils, Distributor Caps, and Rotors are all ordered and in the garage waiting for Saturday. I assume it's just a straight forward job? I've found a few incomplete DIY recaps in the forum, but nothing too thorough.

Peteinjp

Did you go with the 993 coils?

pete

galanevans

Just a straight swap on the 964 setup for now...I'll look at sourcing some of the 993 conversion parts a little a time and look to make the swap on a future 'scheduled' maintenance interval.

galanevans

So - job done...the primary coil seemed to have some oxidation at the base, and the distributor caps seemed to have a bit of char. A couple hours, $325 in parts to Pelican, and fresh coil packs, distributor caps, and rotors has me right. Just went out for a shakedown run and the idle and acceleration is much improved.

Thanks for all the help!

Silvertarga

If you used the Bosch silver coils make sure your cell phone is charged and your AAA membership is current!

Goughary

Don't forget the mention using beru distributor caps....also a soon to need AAA...(only use Bosch caps)

galanevans

Well, I'm double screwed then...silver Bosch coils and the Beru caps and rotors. At least now I know how to do the job straight away next time!

Seriously - if the Bosch coils and their reputation are so poor, how have they not gotten to a higher grade quality by now?

Goughary

Don't sweat the beru caps. They usually are fine.

I've just had the connectors break on a few caps where they are glued in...so keep an eye on those when you pull the wires- or if you ever pull the wires. Outside that, they seem to be the same quality as Bosch- so long as they are in working order.