Hi all,
Ages ago (it seems) I managed to blow up my van on the M25. The fan sheered off the pulley - and went bouncing around between the fan cover and oil cooler - oil everywhere - lots of smoke and swearing... But - the engine didn't seize - I was able to switch it off...

Anyway - I've attempted to rebuild it - so it's been apart, has a new oil cooler and new valve stem oil seals. And lots of time faffing with grinding paste, lapping in the valves. The bores looked good, and the rings seemed ok, so I just bunged it all back together.

She now starts and runs nicely - no bottom end rumbles or anything like that... but, it's like driving a two stroke. Serious amounts of smoke. Actually, it's not too bad at tickover, but under load....

Any suggestions as to what I've done wrong? Or what to check next?

Thanks...

with such a calamitous failure its doubtful the engine was left to run for any length of time

but from the symptoms I'd be looking at a nipped or dammaged piston ring or an badly fitted stem seal - they are a bit of a faff to fit and the ones that come in the gasket sets are easily torn when fitting.

Sean

Or, as I found on the 'rubber glove' engine when putting it back together last week, the inlet and exhaust valve stem seals had been swapped over on one head...

A compression test ( or even better, a leakdown test ) would check if there's any problem with the rings or the bores.
If that checked out OK, then it's likely to be valve stem seals.

ken