Engine Knock after parking on STEEP hill

[oestlarsen]

Folks - I tried to search board, but found nothing to ease my concerns...wonder if somebody has experienced the following:

I drove my trusty ol' 1982 911 SC to a friend's house. He has pretty darn steep driveway. Parked the car. Car ran great when I parked.

About 1.5 hours later, go out to start it, sounds terrible...a knocking sound. I had to limp home, took it very easy, and as I got close to home, the sound started going away. Once home (about 20 min later) - I parked, and revved engine (by hand) from back. I could not really hear any knocking anymore.

When it was knocking, was not knocking at idle, only at slight power..seemed better at a little higher RPM, but as mentioned, I took it very easy home.

Question is -
a. Is motor damaged?
b. What the h... happened?

A few bits of info:
Rebuilt engine at 165K (Top end) - runs like champ. Currently 205K on it and semi-daily driver.

Thoughts?
Carl

[Danny_Ocean]

Did the engine blow smoke upon start-up or after driving it?

[Joe Bob]

Sounds like you sucked some oil in the intake from your oil tank. Is the oil level past the midway mark when you check it...when warm and on a level pavement and running?

If so....that's a bit much. There's SUPPOSED to be a steel wool like restricter in the line but if it sits for a while it will not do any good. Best to park it nose down in the future.

Take it out and give it an "Italian Tune Up".....

[lateapex911]

Hmmmmm...

I had a similar situation, and mine was a rod knock situation. Long story semi short:

I drove the car from CT to Cali in 3 days, and after a long hot day of climbing the Colorado Rockies heading west, stopped for sleep. Next morning, it sounded like a ball peen hammer was banging inside. Ugg!

After sweating a galllon, I restarted, and listened, and it went away after 30 seconds or so. Then after a long hot day of driving in Cali a month later, it happened again. Level parking both times.

I switched over to syntehtic and it never happened again, no matter how long and how hot it was, and it got a lot hotter.

Eventually, the engine had to come out for unrelated reasons, and sure enough, the big end of one con rod was larger than specs allowed. Plain worn out.

I always wondered how long I could have gotten away by continuing to use Mobil 1 and Redline.

I'm hoping that Mike Z is correct, not me!

[oestlarsen]

Thanks for the replies - the car was not overly hot when I parked, and was certainly not stressed or anything. I had just driven about 20 min on a cool Seattle spring day :-)
To answer other question - it did not smoke too badly...but smoked a little more than I would have expected for not having sat for long time (only 1.5 hours)...I'll fire her up in the AM again and see the sound is there again when cold.
Carl

[oestlarsen]

Here is an update:

Started the SC cold today - fired right up - and I could not hear anything at all outside of the ordinary - let her run about 3-4 minutes, revved her a bit, with no sound of knocking at all.

I also pulled the air cleaner cover - everything looked fine.

I did notice a little more smoke than normal...and did not take her out for the "italian tune up" :-)

I guess she's fine - just still wondered what happened and what parts were knocking due to to the oil leaving the area..

Thanks again for the replies.
Carl