Expert opinions needed for engine puzzle!

[morganrue]

Hello all. The question relates to my 1700 pancake engine in my 17972 crossover... and I'll tell it in order.

1) ran well on the drive from UK to here in Luxembourg.

2) started up one day with CLOUDS of smoke out the exhaust- hazard to shipping levels!

3) oil level appeared to have tripled, and smelt strongly of petrol

4) I presumed the electric fuel pump had overpowered a float needle, or grit had unseated it- the only way I could imagine that fuel pumped into the crankcase.

5) drained oil/petrol mix. Refilled with new oil. Rigged the fuel pump to fill the carbs then disabled it..

6) engine re-started fine, no smoke, BUT demonstrated a HUGE oil leak from below.


Opinions/advice please as to what has most likely failed during the two minutes of masssive crankcase overpressure, such that it leaks like the Torrey Canyon.

Quick replies appreciated as I'm fixing this in February outside, and currently its not snowing or raining!

regards

Morgan

 

[StuF]

Where abouts is the oil leaking from?
Does it leak when its just sat or with the engine running?
If both does the rate of engine to garage floor oil flow increase with the engine running?

 

[morganrue]

Only leaked when running- didn't rev it up more to see if the leakage was proportional, due to fear of seizure. appeared to be to the pulley end of the engine.

It MAY have been just a legacy of oil being blown out when overpressured- but I would love to find out where from, even if it stopped subsequently...

M

 

[Paul Weeding]

Check the dipstick boot on the bottom of the oil filler tube... If it has had a new one fitted recently, then the petrol would've accelerated the rate at which it fails...

If it is that, I have some viton ones which are oil stable, unlike the rest that are available in the EU/UK

 

[StuF]

I would top the oil up once you have cleaned up the area where the leak is coming from and give it a quick turn over to see if you can find the exact area.
Will take a while to run it empty if you are nervous - slow and steady!
If you cant diagnose it best to drop the engine and have a good look around - cured several leaks on mine taking a methodical approach
Fingers crossed it was just residual oil from the overpressure