E30 Zone

I have a 1990 325 convertible with switchable auto. On the way to Devon , clocked up 170 mile, I hit telegraph hill if anyone knows it it's steep, haf way up I start gettin smoke from the back end? The temp needle is climbing towards the halfway mark as usual, sits at the first White line no matter how I drive unless it's up this hill, the car isn't struggling or anything and when I hit the top of the hill everything is back to normal. No smoke, temp guage is back to normal no custard in the oil filler no water used. Another 10 mile of drivin still nothin. Lookin under the car it looks oily wet. Could I have blown a seal or blown some fluid out of the dip stick that got burnt on the exhaust?

Could it be engine oil? I have had this problem before, not that often i drive up steep hills but i have parked in a few and when i do my engine leaks.
Could your problem be the same?
Don't know exactly where the oil is coming from, guess i need to jack the car up some day and take a look.
If it's red oil then it's the gearbox spitting out, maybe becouse of too much oil in or overload.

It sounds like a possible sump gasket leak, usually under the bellhousing cover. If you park it on a steep hill with hot oil and look underneath for a drip. or just put a 10mm socket on a few of the sump bolts and see if they're tight. I've often seen them very loose, the leaking oil will hit the exhaust and burn.