Roadtrip - How My Sc Almost Caught Fire

[Shawzy]

This happened a couple years ago in Oct03 on a road trip from Toronto to the east coast, taking the preferred US route through upper NY, VT, NC, Maine.

I had intended of course to post on Pelican right after the adventure completed, but various things prevented it and I won't bore you with details. I only found out the cause of this make-me-bald scare a year later. I want to share this so others now so they can learn from my mistake.

My wife and I had completed the day before a 12hr jaunt from Lake Placid NY to a spot in Maine not far from the coast (drive was great - Vermont was stunning as memory recalls). The morning we left Maine was brisk; a thick layer of frost coated the SC. I started the engine and let it idle for a good fifteen minutes in the driveway before heading out. After scraping the remaining frost off the windows we were off to catch our reservation on the catamaran ferry to Yarmouth, NS. Tunes on, coffee buzz in full effect, I relaxed thinking we had plenty of time to make it before the ferry hit the water. Of course fate had some other plans.

About 5 min down the road my gut went into knots when I smelled something burning...in the first 5 seconds I tried to justify in my head this was not coming from my car...it couldn't be...but every second it got worse. Within moments I realized the odour was electrical. I killed the engine and coasted into the nearest parking lot. I grabbed the extinguisher out from under the passenger seat and ran to the engine bay, ready to see billows of smoke spewing out (my wife had already jumped out and taken off on foot at full speed). Extinguisher in hand I opened the engine lid to find that everything was fine. What the heck?

I investigated as much as possible, but found no evidence of anything whatsoever. My wife had since returned: "If we miss the ferry we can always hit the factory outlet malls - oh yeah, how is the car?"

With all looking ok, I started the engine again and waited for disaster. Nothing. We hit the road again, snaking our way down to the ferry dock, squeezing on in the last moments before the gates closed. All seemed well, no odour, no smoke, as if it never happened.

The rest of the trip was perfect. Other than a few new stone chips and some hot starting issues after running for 3+hrs straight, the SC had another 5000km by the time we got home, and I had memories of driving a sunny cabot trail that will last a lifetime. I am still mocked for taking more pictures of my car on that trip then of anything else.

So what happened? Well I found out the following summer when changing the oil. When under the car I was poking about and noticed my heat-exchanger tube looked rather torched. Upon further investigation, it all became clear. The starter wire had a nice chunk of insulation melted away - and looked as though it had shorted out on the heat-tube spiral wiring. After some thought I figure it all traced back to my 915 rebuild in Aug02 and the frightful morning in Maine in Oct03.

It seems that when re-installing the engine in Aug02 I did not carefully ensure the starter wires were well away from the heat-exchanger. In the excitement of getting the SC back on the road I overlooked this. So why did it take a year for this incident to occur? I believe it is because I had never let the car idle for more than 5min before that morning in Maine. Simply driving the car must have been enough to cool the starter wire enough not to reach the combustion point. When the car was allowed to idle for 15min with no airflow, combustion occurred shortly after. A more simple explanation of course is that after 1500km perhaps the starter wire loosened and got closer to the heat-exchanger.

Whatever the case, the moral is to check clearence and position of your starter wire(s), torque them properly and ensure they are at no risk of being torched.

PS I highly recommend a road trip east. Go in the fall when prices, crowds, and summer heat are down on the low end.

A little sample.

[Beethoven]

Great story. But letting the car idle for 15 minutes in not good. The Porsche gods were angry and punished you.

[Shawzy]

No kidding, but it was either that or take a hammer and chisel to the frost

[Kurt B]

I'm filing that into my brain. Thanks.

[Paulporsche]

Shawzy,Glad to hear all is OK.
Seriously, though, don't do that any more. Start the car, let the engine smooth out for a minute or 2 max, and then drive conservatively until 176F. Idling is bad for any car engine. The factory has recommended what I said for years. Also, if you care, it's bad for the environment. We even have a limit on idling time here in Toronto.

[Wrecked944]

Shawzy! Great writeup. Haven't seen you around these parts in a while. Glad to see you're back!

Last I heard your copilot was a newly minted "fiance". Congrats on converting her to wife status!

[Shawzy]

Hey thanks Janus - glad to be back. Had some time away from it all with crazy work travels. Feels good to be talkin' porsche again.

Congrats on the C4 last time I remember your yellow frog got torched and you were searching for replacement.

And Paulporsche, I realize idle is not good. This never would have happened if the frost wasn't a factor. To tell you truth I cut my engine in traffic and long red lights because I also enjoy contributing to clean air. Crazy perhaps but it everyone did it it would make a difference. Also I don't plan on being ticketed by the cops in Toronto for idling.

Cheers

[Paulporsche]

Good Man!