Generator Warning Light

[Guest]

Good Evening All.

Being a nubie owner of a 2006 Cayman S; I'm hoping the more tech.guys can throw some light on a problem encountered to-day whilst out. I had just filled the car up with 97 octane (Ron ) as I couldn't get to the 'Super' pump , and on 'start up ' the car backfired, or coughed, then started which I've never experienced before ( backfire ), then as I pulled out of the garage I noticed the battery /Gen. warning up on the dash. My first thought was the gen/alternator objected to the backfire in some way. I drove home the remaining 6 miles, then on my drive I switched off...........sat for a while, then re-started......... Thankfully the warning light was now extinguished .
My question is are there any explanations, or the fact that the warning light has gone out, there is nothing to worry about.????
HELP IN SETTLING MY CONCERNS PLEASE.
Phil Knight.

 

[Motorhead]

Hi Phil, Sorry to hear about your minor hiccup. An engine backfire is generally caused by a build-up of unburned fuel in the exhaust system being ignited by hot exhaust gases. Maybe you'd been driving in a spirited manner before filling up and had shut down the engine immediately on arriving at the pump and not let it idle for 10 seconds or so to let it settle down? I can't really throw any light on the reason for the problem you experienced with the generator warning light. Perhaps the DME [ECU in UK-speak] got confused by the backfire and threw up an erroneous warning, resetting itself once you'd turned off the ignition. In future, if you get any warning light on start-up it's always sensible to turn off and try restarting to see if the fault light clears. I don't think the fact that you refilled with a slightly lower octane-rated fuel had any bearing on the problems you experienced. Although Porsche recommend the use of 98-octane fuel, the engine is perfectly happy running on fuels of lower rating, the DME retarding the ignition to avoid knock. Hope that's put your mind at rest. Just continue driving and enjoying your new car. Jeff

 

[dpoynton]

ORIGINAL: Motorhead .... Porsche recommend the use of 98-octane fuel,......

Not wanting to start a long discussion on RON (again!) but when I collected my Macan from Leipzig the other week I asked the question; what ron fuel do I need to use? Answer: Preferably not E10 (10% ethanol version where available) but otherwise any, it does not need to be 98 ron, 95 will be fine. David

 

[Motorhead]

I'm sure that's true David. I think that the reason Porsche recommend the use of 98-octane fuel is to support their engine performance claims --> high octane = high power. It seems that they could be more concerned about ethanol content than octane rating. Jeff

 

[Guest]

Thanks Jeff, for the reassurance , all points duly noted re. shut down procedure. I paid a visit to Moto Elite ( Porsche Specialist ) in Northampton, whereupon they put the car on their diagnostic (OBD Reader ) bit of kit and checked everything out, both mechanical and electrical. Everything checked out A ok, including the ECU. They infact said the same, about shut down procedure, after giving it the 'gun' which I had !! to let it settle. He thought there may have been a build up of unburnt fuel in the exhaust. But he said that wouldn't explain the error code of 'Generator Warning ' he said with all error codes, it's best first to switch everything off, then try a re-start. Sounds a bit like our main PC, if that decides to have a hissy fit, switch it all off, then re-boot. Thanks for that; may see you on Saturday next ? Phil