Metal bits on magnetic oil drain plug

[rmconner80]

Drained the oil to change it and the filter. Car goes into storage for the winter so it gets fresh oil right before, no matter how few miles are on the oil in the car.

On the magnet, there were 3-4 small iron chips attached. I have not seen this before so it is within the last 800 miles (since last oil change). The chips were about 1.0 - 1.5 mm long, and about 0.5 mm wide, kind of a shallow C shape.

We cut open the Mahle filter and ran a magnet through the filtering substrate. There was a detectable accumulation of very fine magnetic metal in the filter as well - but only on the magnet, not really visible on the filtering medium.

Where could this metal be coming from?

I believe the cylinder walls are lined with iron but what else is magnetic in the engine?

The car runs great. 83K mile 1987 944S. Some history: Car was overheated a few months ago and blew the headgasket; recieved a new one at that time including milling the mating surface of the head flat (it was within spec but while you're in there...). Obviously all valves and head aluminum was cleaned and reassembled, new belts, new water pump, new ISV (incidental), new thermostat, new oil, new coolant. This was 800 miles ago and all work performed by very reputable shop (not me!)

Impending doom? Normal?

[flash968]

rings?

[mistertate]

How many miles did it run with the bad head gasket? How is the oil pressure? The cylinder walls are aluminum and silicon, no ferrous metal involved. It seems more likely to be bearing bits than rings.

[flash968]

i would have thought that too, except the bearings should be a non-ferrous material

[rmconner80]

Dang, I thought the cylinder walls were iron for some reason. Guess not.

It did run a while with the bad head gasket, probably a few hundred miles.

Oil pressure is fine, 4-5 bar under load and 2 bar at idle.

[krystar]

got a borescope? take a peek thru spark plug hole and look at the cylinder walls.

or drain the oil and peek thru the oil drain plug.

[flash968]

just saw the coolest remote camera gadget at grainger - only $250 - i think i need to snatch up one of those