Cracked ignition coils

[Bluebox]

Changed my Spark plugs the other day, and noticed that 4 out of 6 ignition coils were cracked !

I don't seem to be having any misfires, but the idle is sometimes a bit erric 750 to 800 RPM.

a) Is this normal, and does anyone what causes them to split like this (see attached photo) ?
I thought it maybe heat or someone has over tightened the two coil bolts.

b) Has Porsche modified the ignition coils to stop this happening again, the part number on my coil is
996.602.102.00, Beru 0 040 100 021.

Regards,
Chris.

 

[Bluebox]

Here my quick fix, just add some glue along the crack to keep out the water, time will tell...

 

[Bluebox]

Also noticed on my 2003 986, that there doesn't seem to be any sparkplug tubes in the plug well !
Is this right ?

 

[Richard_Hamilton]

It's a VERY common occurrence. The latest number for 2003-on is 996.602.104.00, and they come complete with the spark plug connector.

There is no tube in the plug hole.

 

[Bluebox]

Richard,
Thanks for confirming its an common problem, its a shame that you have to buy both the coil and spark plug connector (£37+ each!), as my spark plug connectors are like new.

I would like to find out what is causing the cracking, so I can stop the new ones from doing the same, it looks like a design fault to me ?

Here's an Engine location map of the failures:
Front of car
-----------------------------
Cracked OK
Bad Cracked OK
Bad Cracked Split
----------------------------
Rear of car

Good to hear that there are no tubes on the 2003MY 986, see attached a picture of a spark plug tube...

Regards,
Chris.

 

[Richard_Hamilton]

Oops. Think I might have jumped the gun there - just looked at the PET, and there ARE spark plug tubes.

Try www.eurocarparts.com for the coil packs - they are usually cheaper there.

Edit: You must have the tubes in place or it would be pouring oil out all over the place.

 

[Black80XSA]

The ignition coils generally crack through the heat form the engine/exhaust - some are more prone to this that others, hence why they don't fail at the same time.

 

[Bluebox]

Richard,

Thanks again for your help.
As you can see from my third post photo, I just couldn't see the sparkplug tubes, and there was no sign of oil on the old plugs.

But as you say, it must have them fitted, it's not a problem because there not leaking...
I have been trying to track down a good price for the coils, but I'm not sure if there the correct ones, I want Beru ones:
a) Eurocarparts (under IGNITION COIL section) calls up two different part numbers BERU (£26.68 +vat) 413330110 and 413330111 (£33.96 +vat).
b) design911.co.uk (ID99660210101 IGNITON COIL 996/BOXSTER) @ £ 28.95 +vat
+ ID99660210301 996 and BOXSTER SPARK PLUG SOCKET @£5.99 +vat
c) partsforporsche.co.uk @ 996.602.104.00 (SPARKPLUG CAP COIL 3.6) £24 +vat (says it for a 3.6?)

I think I will try my OPC first and try and get the price down first...

The funny thing it the car seems to be running fine at the moment, should I be rushing out and buying 4 new coils ?
Does the 996 also suffer from the cracking ?

@Black80XSA: If it's heat then its hard to guard against harming the new ones.
Thats why I did a quick location map, to see if other people have had the same coils fail in the same plug location.
It did cross my mine that it could be down to the coil bolts been too tight as the torque setting is only 7.5 ft/lb and the bolts has lock tight on the threads.

Regards,
Chris.

Edit: design911.co.uk price has gone up, must be reading this thread...

 

[Black80XSA]

Coil No.1 is virtually always the first to fail on a 996 due to its proximity to the exhaust

 

[Richard_Hamilton]

Chris - as David says, the 996 is equally susceptible to coil pack splitting/cracking. There are two different coil packs used on the Boxster:

996.602.101.01 - Up to MY2002
996.602.104.00 - MY2003on

I don't know the Beru equivalent numbers. Beru make plugs and coils for Porsche, and quite often you'll find Beru parts in a Porsche box when you buy them from an OPC.

Up to you if you change them now or not. Although your picture looks pretty horrendous, I've seen them in a much worse state than that, and still working. One thing is for sure though - they ARE going to get worse!

 

[Tool Pants]

I must be blind because I do not see a spark plug tube in the picture.

I always thought the coils cracked due to engine heat. I mentioned this to the shop foreman at my local dealer some time ago and he thought it was due to the heat generated by the coil itself.

 

[Richard_Hamilton]

There is a tube between the camshaft cover and the tappet carrier, with an 'o' ring seal at each end. The spark plug connector goes down that tube. I'm not sure what the material is, but I would think it's an aluminium tube with plastic ends. Item 27 in the picture.

 

[GOOFY]

I am going to attempt a spark plug change - is there a special spark plug tool I should use for extraction ??

 

[Bluebox]

he thought it was due to the heat generated by the coil itself

@Tool Pants: Very interesting, I didn't think of the coil itself !
I still think its a design problem with the coil itself.
My coil has the following part number Beru 0 040 100 021, but the Beru sites states its 0 040 100 036 (code ZS 036) for 2003 MY.
But the Beru site has know to be wrong in the past.
Have Beru done a design change, may send them a mail and ask them why there coils keep cracking ?

http://www.beru.com/english/produkte/produktfinder.php?hersteller=PORSC&modell=BOXSTER+%28986%29&typ=2.7&ktypnr=16859&action=step04

@Richard: Thanks for the picture, I don't think the tube made from aluminium, but could be on the 2003MY.
I know its plastic on a 1999 MY 986. Take a look a this renntech thread, Tool Pants has a photo of the tubes.
http://www.renntech.org/forums/index.php?showtopic=3052&hl=tube&st=0
Also take a look at page two of this thread, the older 1999 MY 986 has a different coil pack, and you can clearly see the tube in the spark plug well. But on a 2003MY you may be right about the aluminium...

@Black80XSA: So the 996 also has problems, but that does look like a exhaust heat problem.

@GOOFY: You can use a standard 16mm spark plug socket + extension, but you have to be very careful about the length of the extension as the front plugs have suspension parts in the way.
Also don't forget to remove the inner arc plastic wheel cover (2 plasic nuts) next to the mud flaps.
I made my own tools using a Halfords long reach plug spanner and cutting it down in size, it was only £4+ and the plug fits perfect in the end.

Regards,

Chris

 

[Bluebox]

Quick update:

a) Just rung the OPC to confirm the price of the Coils, £33.96 + VAT (-10% PCGB discount) = £35.92 each !!
I also asked about the part number on the new one from OPC and I can confirm its Beru 0 040 100 021 and XAS1
(So the Beru site looks wrong or does there part number include the Spark plug socket ?)

b) Also asked if 2003MY 986 has spark plug tubes and OPC said YES and there made of black Plastic (£2+ each).
I can't see mine ! Anyway there not leaking...[]

Regards,
Chris

 

[Tony Daniel]

Europarts are £26.68 for Ign coils( 03>), £2.14 for pipe, £2.10 for the two O rings +VAT.

Comes to approx £36 per pot. I replaced them all on my last car although they were still working fine, its just the outer plastic that splits.

Has anybody had these fail or is it just another Porsche money making scheme?

 

[jcorallo]

[FONT=arial"]Strangely enough, for my 1997 2.5 Boxster, at Eurocarparts the Bosch units are cheaper than the Beru.

Bosch £23.69 + vat each = £27.84
Beru £25.24 + vat = £29.66.

Thats a nice price for genuine Bosch stuff.

I personally dont like Beru - I've found it to be inferior than Bosch stuff.

If you want to see cracked coilpacks, see what I found under my car:

http://img.photobucket.com/albums/v727/jcorallo/porsche/coilpacks/IMG_1487.jpg

Jules

 

[jpbecker]

My 54 plate 997 had cracked ignition coils and they have been recently been replaced by my OPC after me hassling them under warranty. It seems to have improved the cars idle a fair bit since replacement. The car used to have a nasty high freq shake at idle. Surely cracked coils allow the ingress of moisture, promote corrosion and change the resistance of the coils, resulting in reduced performance. Porsche don't seem to be interested until the diagnostic gear diagnoses a fault. By this time the car will be unpleasant to drive.

 

[tim court]

Similar story - Car in OPC for service and renewal of warranty....

All coils are cracked and require replacement.... Warranty? - No chance! - if a missfire was indicated then they would be replaced under warranty, but the car is running fine.

So I said I am having second thoughts about this warranty lark but before I had time to ponder they called back to say all would be replaced free of charge! Result!

 

[Bluebox]

Thanks guys for your feedback...

@Tony Daniel: "just another Porsche money making scheme" only when there not under Warranty.

@jcorallo: Your coils look very bad, I will take a look at the Bosch versions...
Good picture showing that its only the transformer case thats spits (as Tony says there can still be working fine when cracked).
Was your car running OK before you changed your coils ?

@jpbecker: You say it improved the cars idle a fair bit since replacement of the coils.[8D]
Funny, my idle is now rock solid at 750rpm and the slight kangaroos when moving off in traffic has gone.
Not sure if this is down to changing the spark plugs or sealing the coils with Aroldite Rapid epoxy resin to keep the water out ?

@tim court: Thats bad about no replacement under Warranty.[]
Your better saving up your money from not having a Warranty and spending it wisely on jobs that need doing on your car.

I thinking with the PCGB discount it worth just buying coils from the OPC, if you add up the cost + Post etc..
But must look at the Bosch coils first, I going to add more Aroldite first to my cracked coils and see how the coils perform.

Regards,
Chris.