oil blowing out of dipstick tube - help!

[Goody]

I had to think about that for a moment, me thinks it means Wide Open Throttle and he over rev'd the engine for a short time.  That would explain the bent push rod.

[thebrookster]

Goody has the nail on the head, I was referring to the incident hyperhale mentioned at the start where the accelerator got stuck open for a length of time with no load on the engine, which is the reason he started getting oil out the dipstick!

Cheers,

Phil

[JohnD]

Ah! So!
Thank you!

John

[Goody]

Could have been worse.  I have seen rods go through the block, out the oil pan and push rods trough the hood er bonnet.  Any engine, gas, diesel or steam will fly apart if over rev'd with no load. Due to the laws of nature, their is a max speed for any piston. Try to excede and BOOM!

[hyperhale]

Nick_Jones wrote:

It's possible that the bulk of your extra blow-by was caused by the loss of exhaust valve opening on no3.  

You reported it as "driving fine" after the over-rev incident, so it must have been opening a bit at least and allow no 3 to fire.  However, it was probably struggling to clear the exhaust after firing giving higher cylinder pressures, for longer.  

With more extreme loss of lift even non-opening exhaust valves you get weird running issues caused by exhaust (or just compressed air possibly) being ejected back out of the inlet valve due to residual pressure and it can also cause piston damage due to overheating by compression effects.

Now you've got it apart, with a bit of luck all you'll need is a quick hone of the bores, new rings and new bearing shells.  I'd have a real careful look at number 3 piston though - it could have been suffering on the drive home.

Doubt the bent push-rod was caused by valve/piston contact - these are a long way from being interference engines.  Struggling to think of a good reason for the bend when the rod was apparently still in place.  Over-revving causes valve bounce which sometimes unseats pushrods, which then get bent by other valve gear, but they don't put themselves back on afterwards!

Nick

Nick I think you were right about the blowback caused by no3 exhaust valve not opening fully.

Following a very in depth examination , new pushrod, minor valve seat grind, decoke, honing and new rings and bearings she's back on the road.

And not forgetting glueing down the loose carpet that caused the whole out throttle issue.

Thanks once again to you all

[don cook1]

Good to hear that a relatively cheap repair has got you back on the road.