Arrrghhhh misfire

Got to work in the pouring rain then out if the blue sat on idle dropped a cylinder or two. Unfortunately no time to look at it as typically I was late and it was pouring with rain. Felt like a coil pack to be honest. I'll have a look after work and narrow it down a bit. I went on eBay and shocked to see 6 coil packs were only £99........this is dirt cheap. They are Beru or so the advert states and beru is top class stuff, or was. I'll keep posting when I find out for definite the cause. No mil light, no smoke, no noises.

Given the rain I'd say coils are a fair assumption. Even more so if there's no record of them being replaced. I ended up doing mine recently when I replaced the leaking spark plug tubes. All of mine were fine but 3 got stuck and the rubber tore when removed so I got 6 new Beru ones from Frazerparts Its not a difficult job. Just awkward.

I think in the history it said coil packs replaced but fairly sure it was only 2!! Why you would only change 2 is anyone's guess.

I bought 6 BERU coil packs for the same. Great value

Superb. At that price almost a service item. Annoyingly it won't misfire now and ran fine on the way home. It's dry tonight though!!! More reason to think the wet this morning mate the coil short against the metal of the engine/head. I think I'll do the plugs as well. In theory they have only done a couple of thousand miles but judging by the horrific state of the front metal brake pipes (corroded through nearly) missed on the service, it makes you wonder what was actually done. Porsche specialists eh lol.

Basically the coil plastic outer cover cracks due to water ingress over time and the soft iron core swelling up with rust ... design fault . When its raining or you have washed the car water can get into these cracks and causes .. well ... issues ! Cracked coils only cause issues when wet . It a coil isn't cracked its not normally replaced .. common to see a couple of new type coils on a car with the rest old type .. If it aint broke dont fix it . Customers decide on this though .. garages fit what the customer requests . Btw .. we don't remove heat shields on a service and it's hard to see the coils .. easy if removing for say a plug change but not so on a normal .. minor service ... we just peer through a small gap in the base of the heat shield at the bottom of the coils .

I'm aware garages fit what customer's request however, at the small cost of a set of coils over just replacing 2, I think it's false economy to not fit a set. A car with over a 100k on it and getting a full service including plugs, (coils are out anyway) the garage SHOULD impress on the customer that it's false economy. Or maybe the garage considers they will get repeat business when the car returns at a later date with a misfire. At the same time as the service the car also had IMS,RMS, and plenty of other work. I think the bill was 5k. The hard brake pipes I replaced were corroded through and just about to go pop. The car had a VERY recent set of front pads!!! Anyway. People have differing opinions of what "good customer service" actually means.

The ones you've seen at £99, are you absolutely sure they are actually Beru and are for your car? Mine were £180 for 6 from Frazerpart and that was the absolute cheapest I could find only 2 months ago (996.2 are about £15 cheaper). Porsche charge around £70 per coil and I dare say some Indies wouldn't be far off. So with that in mind I can well imagine why someone would say just replace the 2 cracked ones at £140+ a few hours labor instead of just do all 6 at c£420+ a few hours labor. Especially when there's no real benefit to replacing perfectly good coils. It's a bit like replacing all 4 tyres because 1 has a puncture.

I agree with Uncle P, bought set from Frazerpart in May and I couldnt find them any cheaper elsewhere. Known supplier means you are guaranteed the genuine article. By the way the latest design has a different length bolt to hold them in place so if that isn't included you'll have to buy them separately. This was the coil packs on mine when they misfired, appeared to be 4 original ones there so not done too badly timewise on a 1998 car! https://porsche911owner.blogspot.com/2020/05/porsche-996-coil-pack-cracked.html

If I'm right you say paid £180 for 6. The coils are removed to replace the plugs. No extra labour. So according to your figures it's an extra £80 over the £99 for the six I've seen advertised. The as says Beru. I find it hard to believe someone would make fakes. Possible I suppose.

How much did you pay for 6?

I paid £180 for 6 including the bolts. The one I'd seen on eBay also listed as Bremi but does look to be the same. As a "while you're there" job it's also worth doing the spark plug tubes if there is any sign of oil leaking

Remember a garage will probably mark prices up or might only use OE which costs a lot more. You're correct in that a specialist wouldn't take any longer to do the coils and plugs than they would to do the plugs alone. But it's a 1 or 2 hr job for a specialist so tripling the number of coils you replace at garage supplied parts prices would maybe add 50% to the price. The parts then outweighs the labor on such a job. Not saying it's what I would do. I'm the sort of idiot that replaced a full set of good coils along with many other working parts "just because". Electrical components are some of the most commonly faked parts. Knock off spark plugs on eBay are particularly common. The £99.99 beru coils for the 3.6 look legit though. Not sure how they manage to do them at 50% less than the next cheapest place on eBay but worth a shot.

Hi Uncle P, not quite a 'like for like' comparison re: tyres!! During my most recent service, the indy spotted 2 coil packs with cracks in them (no misfire symptoms at the time!). I tend to use the car pretty infrequently, and when I do, for very long journeys. My indy recommended replacement of all of them as dumping unburnt fuel into the exhaust / Cats for extended periods will quickly overheat the exhaust and ruin the cats. I went along with that suggestion as a precaution. I only want to have my car looked at once a year so this further supported the suggestion. Appreciate that those who regularly 'get under the car' might have a different view.

I'm not sure this is on topic, but I'd rather have four matching tyres than four matching coil packs!