Plenty of platinum in northern CA in the north west corner. Just no roads/railroads to move...

1 mile out from my house, the engine starts to run rough and then the check engine light came on flashing...... Called my indy Porsche mechanic and he said it probably is a cracked ignition coil, but not to drive it. So, I am waiting for a tow truck. I guess the unspent gas goes through the cats and burns them out.

Any reasons I should be worried?

My '99 started running rough and triggered the flashing CEL, so I pulled over and the light went solid. I was with a group and fortunately somebody had a code reader and found it to be P-0306 - misfire on cylinder 6. I was able to reset the light and drove the short distance home. I ordered and replace the ignition coil and all was good, so hopefully your issue is similarly minor. Good luck!

which can arise from a bad coil or plug. Without knowing the error code(s) though just a WAG.

At this time I don't think you have any reason to worrying. The engine didn't make any scary noises so chances are nothing really serious has happened.

Besides, do I correctly note you have 175K+ miles on the car? Are those coils originals? If so one or more coils may be due to be replaced. Or maybe not: My 02 Boxster with over 242K miles has its original coils and several of them misfired a while back, 3 or so, spread over both banks. I cleared the codes and have been driving the car now over several months since and the misfires have not returned.

Sincerely,

MarcW.

Thanx for the data. This "new" engine has a bit over 125K on it and yes, they are the original coils. For all I can remember, the water pump just went a few months ago and this new issue and the pump are the only things to have gone wrong with this engine or its components. This car is nothing like my old 1970 Buick Skylark which occasionally ejected parts at the most inconvenient times and always sounded like... well.... and old GM executive laughing.

or even just in inclement weather in the warmer months the coils could very well be bad, even with just 125K miles on them.

As a test if you want to go to the trouble get a new/clean spray bottle (hardware stores sell them in the cleaning supplies area or sometimes in the plant area for misting plants) and fill it with distilled water and mist the coils and let the car sit a bit and then start the engine. If the coils are bad... you'll know it when you start the engine with 'damp' coils.

Anyhow, some areas of the country are harder on coils than others.

When I spoke with the techs here in my area about replacing coils they looked at me like I was crazy. Coils just don't go bad here in this area I guess.

In fact long before I read reports of coil related misfires here in the USA I encountered reports of coil problems in the UK Porsche mags and later on the boards. It was coils coils coils. (And brake rotor corrosion so bad the rotors would have to be replaced.)

Must be the weather over there.

And UK drivers have it even rougher because they drive on the left side of the road. As a result the left side of the car gets more splash and stuff kicked up and it just so happens the #2 bank has the coils located just a bit further back than the coils on the other bank so the left side coils get subjected to even harsher conditions than those of the right side of the car of say USA cars.

The 911 cars with the engine set even further back and subjected to even more road splash fare even worse that the Boxsters.

Sincerely,

MarcW.

I restarted the car about 10 mnts after I got the shudder and light.... it shuddered and the light flashed with that restart. Tonight it seemed fine as I pulled it around for the flatbed. Great. It better light tomorrow at the repair shop. I will post what it is hopefully tomorrow. My mechanic is pretty sure it is a coil.

Other than the spray method, can the mechanic tell if a coil looks bad? In other words, can he identify any "going to fail" coils? A tow will pay for a few of them so it may be prudent to replace a few... but which ones?

Quote
Bruce In Philly (175K+)
I restarted the car about 10 mnts after I got the shudder and light.... it shuddered and the light flashed with that restart. Tonight it seemed fine as I pulled it around for the flatbed. Great. It better light tomorrow at the repair shop. I will post what it is hopefully tomorrow. My mechanic is pretty sure it is a coil.

Other than the spray method, can the mechanic tell if a coil looks bad? In other words, can he identify any "going to fail" coils? A tow will pay for a few of them so it may be prudent to replace a few... but which ones?

well, he has the error codes which tells you (him) which cylinders experienced misfires so those coils are suspect right now.

Before you have the car towed, if you want to go to the trouble, you can clear the error codes and resume driving the car again. If the misfires come back read the codes, note the cylinders and then any duplicates from the previous incident those are the coils you replace. Of course you don't take the car out on a long drive but hang around close to home, in cell phone coverage and you belong to a good auto club so the tow's free or at least low cost.

Or you can clear the codes and swap the coils from those cylinders that misfired with those coils from the cylinders that did not misfire and see if the misfires follow the coils. If they do, well, you have pretty good indication which coils to replace.

If the misfires were coming from one coil and upon inspection this coil was obviously showing signs of deterioation while the other coils looked ok (not as 'dry' looking, no signs of any cracking of the coil body, all the rubber on the coil still pliable and not cracked, etc.) then replacing this one coil makes some sense.

If you get two coils on one cylinder that prove to be suspect, bad, then I'd suggest you just replace all 3 coils on that bank. Chances are while the one lone coil would be ok for a while it would sooner rather than later cause misfires and you'd be back at the engine again.

If 3 coils are bad or you have coils on both sides of the engine that are bad this makes a case for replacing all 6 because as I mentioned above chances are the good coils would soon be misfiring and you'd be back at the engine again.

You can price one or 3 or 6 coils and see what the cost is. Labor to replace one or those on one back I believe would approach the cost to replace all 6. Of course, 3 coils cost less than 6 coils, but there's a good argument for renewing all 6 so each cylinder once again is on equal footing with every other cylinder.

Sincerely,

MarcW.



Edited 1 time(s). Last edit at 06/07/2011 10:50PM by MarcW. (view changes)

Just had this happen to me several months back. Freaked me out! The car started up rough and flashing CEL. I took it to the dealership and they "couldn't find anything wrong" with the car. Apparently, the next morning when they went to look at the car, it was "fine".

I took it to an indy.

Turned out to be coils.

I replaced all of them and the plugs for piece of mind. Sure enough a a few coils had developed cracks and the plugs were pretty worn down. I hope everything works out... I think you'll be fine.

Coils are really pricey... unlike me, check them all and the plugs for that matter. At 125k miles it would seem logical that some would need to be replaced. My car had about 50k miles on it when I had my (similar) problem.

Good luck!

other. The Turbo after sitting out all night in a motel parking lot in the driving rain and the Boxster just sitting under a carport in wet/damp weather.

Since the Turbo was under warranty I took it to the dealer and the tech noted the misfires but simply told me to clear the codes and drive the car. If the misfires came back of course the coils would be replaced. They have not and that was over (at least) 5K miles back and the car has been in wet weather, snow, and such more than once and has not misfired once.

Ditto the Boxster. It sits outside in the elements uncovered and gets wet but so far has not repeated the misfires.

Sincerely,

MarcW.

and never encountered any 'bad gas' symptoms.

The Boxster got treated rather differently from its norm. I started the engine and it only ran a few minutes at most as I moved the car into the covered parking area. The weather was changing and getting cooler and more humid but the weather was dry and so was the car.

The Turbo as I mentioned sat out all night in a pretty good rain storm. I already knew the engine would get a bit wet because after washing the car upon engine start the belt squeals from water on the belt. But the engine has never misfired or any any way acted up after a car wash.

Since then both cars have been fed a varied diet of gas and both have been washed or sat out in the rain and been driven in the rain and neither engine has misfired any. The Boxster's check engine has come on a couple of times since but it is always that P0430 which is due to a converter that is wearing out. Usually by this time the converter's working pretty good but because of the cooler/wetter spring the check engine has come on again and again. Cooler/wetter weather just seem to disagree with the converter.

Sincerely,

MarcW.

although I grant you platinum, paladium and rhodium do not exist in great amounts.

Anyhow, whether the converter's performance can be rejuventated depends upon why it is dimished in the 1st place.

In my car's case I think the performance is down simply due to the result of erosion of the catalytic metal deposits on the working surfaces of the converter. The metals are not layered on too thick and over time the active metals will come off due to the corrosive effects of the exhaust gases, heat cycles, and the violence of the exhaust gases.

In other cars, the converter's diminished performance may be due to deposits either over time (from say using a very low quality gasoline or running the wrong oil) to the after effects of a failed AOS. In these cases using a fuel system cleaner (Techron) once or even twice and switching to a high quality gasoline may resurrect the converter.

Sincerely,

MarcW.

[en.wikipedia.org]

In high school I won the American Chemical Society award, but that was ages ago, well before the invention* of rare earths. I don't remember... did I say it was a long time ago?




* I keed, I keed!

equipment/stuff in and stuff out.

You can pan for platinum just like gold. Look for sand bars in rivers coming out of the mountains of northwestern CA. The darker the sand the better.

Or if you want to possibly find bigger pieces of platinum, you can also look into the areas where the river drops stuff. Rivers are natural sluice boxes and nuggets of platinum float about as good as nuggets of gold.

BTW, the other northern corner of CA is suspected of containing large amounts of petroleum and gas. Trouble is the deposits are covered by thousands of feet of sediment washed down from the mountains and to make matters worse a huge basalt lava flow (which had its source of lava located in southeastern OR) covered that silt with up to several thousand feet of lava over hundreds if not thousands of square miles.

Sincerely,

MarcW.

we had to change all six coils as they were cracked, still had flashing light!! Told to change the exhaust as it was filled with god knows what - still had flashing light, finally had to change the temperature control sensor all in all £1200 pounds, still dont know which bit was correct but its sorted now!

WHOA! That sounds pretty intense! Did you drive the car while you had the flashing CEL? Stuff in the exhaust sounds odd to me. Was this at a Porsche shop or independent? Did you get an OEM exhaust? I'm very curious about that. I know that if you drive the car when it's misfiring (with CEL flashing) you can get unspent fuel into the cats and damage them major. Did they say anything you about the catalytic converters? It sounds to me, from what I have been reading from others above, that the misfiring/flashing CEL can go away. It did for me, but I still didn't want to have that happening to me again. As I said above, when they finally did pull the coils, I had cracks in many of them and I had already paid for the parts (would have had to pay to ship back and restock). It was good piece of mind. I'm crazy about my car so it was like a "50,000 mile 10 years old birthday gift".

I don't know much about the temperature control sensor, maybe others will chime in...

I'm glad your car is ok now!

hi we had cracks in the coils, they changed all six at the local peugeot garage, nearest porsche garage is over 80 miles away! the guy locally is reliable though, the light still flashed, when he did some tests it showed some problem with emissions i think - had a slight language barrier problem as the car was in spain and i am english, anyway, he showed us all the exhaust clogged up and the cats inside were crusty like baked honeycomb, he repaired the cats but the exhaust had had it from what we understood, so got a new sports exhaust from porsche shipped over and fitted that, still the flashing light, he tested the air temperature flow sensor and found that that was faulty, this was a pricey part too, over 300 pounds sterling, fitted it light went out the car runs like a dream, from what i understand the dodgy exhaust, clogged cats caused the other probs, plus the coils were the originals so probably on there way out anyway,

He started it up this morning and it ran fine. Codes said misfire on 6.

Since I will be up for a plug change in 3.5K miles, he recommended changing all 6 plugs and coils. I should have the car back tomorrow at 2:00.

is a reasonable course of action.

If just one relatively new coil was acting up that's a case for replacing just that one coil, but in your car's case even though only one coil (# 6) triggered a misfire the others are close to the end of their life, and you don't want to pay to replace all 6 coils one coil at a time.

Sincerely,

MarcW.

I replaced the coil on cylinder #6 based on the error code. Two weeks later, I got the same issue on cylinder #2, so I ordered 5 and replaced them all. They can be found on-line for ~$45.