Sparks from windscreen vents!

[zithlord]

Something strange a cured today. I picked up a beautiful 78 SC with 34.000 miles. It looks like it has 10.000 miles both inside and out, incredible. In Norway it was snowing yesterday and I turned the heater (both sides) on max, and set the airflow to the windscreen. Nice warm air cleared the mist on the screen in just a few minutes. BTW the car will not be driven in rain or snow, but I had to move it to an aircraft hangar for winter storage.

After approximately 10 minutes I noticed some small pieces of black sooth coming out of the vent close to the windscreen, mostly on the passenger side of the car. I am not talking about large quantities, but a few bits. The bits are black and hard like coal. There was no bad smells (the car smalls like new) during this. After another 5 minutes I saw a couple of sparks flying out of the passenger side vent, and immediately turned off the heaters. I got a bit scared as my first thought was a electrical fire or something. But because of no smalls present, I turned on the driver side heater after a few minutes. Still a few bits of sooth but no sparks!! Could this be some remnants of a rodent or nest in the heating/air system? If so where do the sparks come from? If sparks are developing it must be near the heat exchangers, or could something else cause them? The heater has not been in service for the last 9 months and the car has been driven only a few miles.

John

[kodioneill]

i would guess it is the heater hoses. possibly have become brittle.

[john walker's workshop]

particle matter of some sort in the heat exchanger, near an exhaust pipe. mouse nest/dog food, etc.

[RWebb]

Zith - occurred, not a cured; just FYI

I would jack the car up; remove one end of the flex hose from the heatX and shove th emost powerful shop vac you can get into each end, then do other side.

Also try to vac out the cowl intake, and interior outlets.

If it still occurrs, you will need to (next) dismantle the front blower/hoses there.

Debris is one thing, but sparks are more worrisome.

Good Luck!!

[zithlord]

Thank you guys! I will go down to the winter storage next week, I will jack it up as you suggest and blow air/vacum the hoses and exchangers.

Have a nice day!

John

[911pcars]

Where there's sparks, there's also smoke.

Don't let the smoke out. Disconnect the battery until you find out the source of the combustion process.

Sherwood

[zithlord]

Sherwood, the strange thing is that there was no smell and no smoke. This leads me to think that the remains being heated are already burnt to coal, and that it has not been detected because the heater has not been used for 9 months.

John

[R_Builder]

Did you have the fresh air blower running (I suspect not since it was so cold outside)? One thing inside that unit that breaks down quite easily and can get blown out the vents are the round foam seals that are on the metal dampers that close off the 2 outlets....

[john walker's workshop]

for sparks, there would have to be something laying on an exhaust pipe inside the exchanger body. maybe a paper bit from a heat hose. you wouldn't get sparks from anything farther down the line, except maybe a mouse with a nicotine habit.

[RWebb]

what if the blower motor was self-destructing?

maybe that could do it...