dbv1

Just a quick followup on the spark plug and coil change job my 2 friends and I did today.



-First, thanks to Dave R. for putting up a DIY for the job and USMC_ DS1 for maintaining that index of DIYs at the top of the forum.

-No need to remove the muffler or parts of suspension. Won't help one bit in my opinion.

-Lots of fiddling around and extensions, universal joints and very small ratchets needed. Getting the plugs and coils out and putting the new ones in wasn't that big of a problem with the right tools. Getting the back-most connector back on the coil was a pain.

-My plugs were in excellent shape (front car) but the ones from the other car were completely covered in soot. Not sure what to make of this, maybe bad gasoline? Almost every single stock coil was cracked up on both cars. One of the coils on the other car nearly disintegrated. Both cars are 997.1 C2Ss and have 47K on them. It's a good idea to change both coils and plugs at 40K. Not overjoyed the OEM coils did so badly. I have a set of coils on my turbo Audi that have 40K on them, car is modified and winter driven and they aren't anywhere near disintegration.

-We got replacement coils for $40/pop but they are definitely different from stock. Hard plastic on the connector versus rubbery on OEM. 3/12 cracked during installation. I don't think it'll cause a problem though because we packed them with dielectric grease and there's the boot on top of them. We took both cars out on a slow warm up and then a very spirited drive and the new coils perform just fine. No misfires, both cars run fine. Not sure whether we're going to have any problems with the new coils, long term.

Devil Boy

Looks like a good day of wrenching.

dbv1

Yup, 7 hours total.

USMC_DS1

Congrats on the successful install of both plugs and coils. It's gratifying to DIY these otherwise pricey p-dealer service items. Curious as to which coils were used. Sounds like you might have gone into the project with plugs on hand and not coils. Once you determined that the coils needed to be replaced then you tried to source them locally (p-dealer will sell a set for the price of a kidney) and settled for an after market type. Just guessing but that's the approach I might have considered in that position. I prefer OEM parts if possible especially if they are priced similar to AM parts. The difference between the OEM and AM coils may be to reason why some of the new coils cracked even though you may have used the proper torque value of 7.5 ft-lb. to tighten the fastening screws. I suspect the AM coils may require less torque. For future reference the OEM Beru coils are available from pelican parts for $42.50/ea. http://www.pelicanparts.com/cgi-bin/...9%2C%20Each%20

As an FYI... I kept 2 off the best looking old coils in my emergency kit JIC I ever get stuck somewhere w/o available parts. As you've experienced... coils are fairly easy to replace if you find yourself in a pinch while on the road.

dbv1

Thanks!

I'm in Canada and my two local sources were out of coils and I wasn't going to pay the dealer price ($80/pop IIRC). I was in a hurry (other car was misfiring badly, yup, it was the disintegrated coil) so I just got some from eBay. Didn't expect what I got. Didn't know about autohausaz.com or pelicanparts. Live and learn. AM coils seem fine so far though...

We also kept the best looking coils as spares. Kept my plugs too.

It was just pieces of the connector plastic (right where the plug goes in) that cracked on AM coils, nothing to do with the tightening screws. Coils are fine themselves. It was cold here yesterday and hard plastic becomes really brittle when it's cold.

scott10s

I just had my coils and plugs changed and noticed significant improvement in acceleration. The car just feels so much quicker. My car has 44K miles on it. I was wondering if you noticed any increase performance like I did.

MichaelL

My experience with plugs at 38K/4 years replacement was that they were all basically OK, a little bit dirty. Changing them out was cheap insurance. Had all the coils replaced shortly thereafter. Misfire & blinking check engine light. Coils are not durable in cars that are used on roads that are salted or cars that are not garaged. The coils are in a vulnerable location. Change them out with the plugs.

dbv1

Nothing on my car but my plugs were OK and coils were still functional despite the cracks. The other car is definitely better but that not really surprising considering the soot on the plugs and one nearly disintegrated coil.

Edgy01

Would a harsh environment lead to cil failure? (Canadian winters can't be too nice)...

I'm at 75,000 on my plugs and coils and they run perfectly for now!

Renzsport

Nearly a mirror image lol.
Thanks for the details, good to know this stuff when eventually i do mine...

Fahrer

I am sure the coil housings are made from glass reinforced polyester ( PBT). This is a common and relatively inexpensive enigineering plastic. One of its weaknesses is limited hydrolytic stability. Elevated temperature and moisture will eventually degrade the material.

MattAu

I think I read or heard one of the reasons for changing the spark plugs at 4 yr is because after that, there is a chance the plugs have seized and it will cost a fortune to remove. Have anyone actually encountered or have known anyone who has actually encountered any difficulty in removing the plugs after having gone past the 4 yr mark?

USMC_DS1

Not on a Porsche but my son's 21 yrs old 4Runner had that issue. He forgot to use anti-seize on one plug. It was parked/driven down in Galveston, TX for a year. That one plug seized up and it was a real PITA to extract. Now Porsche recommends no anti-seize on their plugs as these new plugs don't require any... the plugs already have a metal alloy coating of some type on their threading which acts as a lube but it's not wet to the touch. I still don't like the idea of waiting so long to swap plugs though so my plugs are coming out every two years. Just not worth the chance and it's only $60 for the set if you DIY.

dbv1

A followup on the followup: one of the new coils failed after about 100 km on a hot day when the car had heated up fully. I'm thinking it must be a fluke, seller sent me a replacement but I used one of my old coils in the interim. First symptoms of that coil failing was a very slight hesitation under acceleration once the car warmed up. Not 20 km after I replaced that first failed coil I'm getting that slight hesitation again. Another coils was going to go. Now I know it's not a fluke. Ordered a new set from Pelican and installed them. It's all good now. One the bright side, it now takes me less than 2 hours to change the coils, I got better.

3 lessons learned from project:
1.) Get quality parts.
2.) Change plugs every 40K.
3.) Change coils at the same time. My car was kept very well (garage, no salt ever) and the coils were starting to crack up anyway.

dbv1

Two shots after a detail, with the new coils of course: