Bukh DV10 goes bang

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Matador

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Well, it just slowed down and stopped on the way down the river. No compression, rocker cover filled with emulsified oil, broken exhaust valve spring, small plastic breather pipe held on with jubliee clips [!] unattached at one end, oil in sump ok. Any ideas on this ? Fed up, lost a weekends sailing. Cheers, Chris W.
 
Dont read until tomorrow

broken exhaust valve spring
Click to expand...

Completey broken? so that valve has dropped or at least failed to close.

If so piston probably hit valve. broken head off valve. Broken valve smashed up piston and wrecked head!
possible bent con rod

Big hole in pocket. Many weekends sailing lost :mad:

complete strip down and rebuild

new head and valves. New piston and rings and con rod maybe

hope that crank is Ok and that bore is not scored


On the bright side .... there may not be one :(
 
Last edited:
Matador said:
Well, it just slowed down and stopped on the way down the river. No compression, rocker cover filled with emulsified oil, broken exhaust valve spring, small plastic breather pipe held on with jubliee clips [!] unattached at one end, oil in sump ok. Any ideas on this ? Fed up, lost a weekends sailing. Cheers, Chris W.
Click to expand...

May not be a big deal.

IF and it is a BIG IF your valve spring failed at low rpm you may have been lucky and the valve is undamaged.

Rocker cover off.
Piston at TDC NB IMPORTANT
Slacken off tappet
disengage pushrod [<I>I don't know this engine but on a typical diesel this is possible. </I> ]
Remover valve collets
Move piston off TDC a small amount and see if the valve moves freely.
IF YES
Return piston to TDC
fit new spring replace collets etc.

See if it has compression.
IF YES

See if it starts.
 
TQA said:
May not be a big deal.

IF and it is a BIG IF your valve spring failed at low rpm you may have been lucky and the valve is undamaged.

Rocker cover off.
Piston at TDC NB IMPORTANT
Slacken off tappet
disengage pushrod [<I>I don't know this engine but on a typical diesel this is possible. </I> ]
Remover valve collets
Move piston off TDC a small amount and see if the valve moves freely.
IF YES
Return piston to TDC
fit new spring replace collets etc.

See if it has compression.
IF YES

See if it starts.
Click to expand...

Not really a good plan, there's a distinct possibility that the valve may be bent; this really needs the head off and a new valve & spring at a minimum. If the valve is even slightly bent, the valve head will very likely drop off after a couple of hours running and probably damage the rest of the engine beyond economic repair. While I think VicS's portent of doom is a bit pessimistic, I think your suggestion is overly optimistic.
 
Well while it might be better to remove the head and even do a complete engine strip the valves on a small diesel will be in line with the pistons so there is a fair chance that the valve will not be bent. As you need a new valve spring anyway what is the loss?

Do as I say and if you have compression then the engine should start.

Sure the valve could have been stressed but I would say if not bent then it should be OK.
 
The problem with that is that if the valve is only slightly bent, the spring will have enough closing force to give you compression to start, especially in an old engine with a gunked up combustion chamber. Then the head falls off 5 hours running time later and means you can't afford that kitchen/holiday/diamond necklace for the OH, you end up with a divorce and end your days drinking cooking sherry in doorways arguing with yourself about the false economy of not buying a head gasket and a new valve to do the job properly. :D
 
Born again Bukh....hopefully

Thankyou All for your replies and wisdom. Valve spring was in 4 bits. Took head off. Friend who is an engineer inspected the valves and declared them 'not bent', then showed me how to re-seat them. New springs and gasket set arrived today. The new springs don't seem as
strong as the old ones.Now to put it all back together, hopefully I can remember where everything goes.... Anything I need to look out for? Then the moment of truth. SWMBO has even mentioned new engine, so things are looking up.Cheers, Chris W. (might even get out this weekend)
 
Matador said:
Thankyou All for your replies and wisdom. Valve spring was in 4 bits. Took head off. Friend who is an engineer inspected the valves and declared them 'not bent', then showed me how to re-seat them. New springs and gasket set arrived today. The new springs don't seem as
strong as the old ones.Now to put it all back together, hopefully I can remember where everything goes.... Anything I need to look out for? Then the moment of truth. SWMBO has even mentioned new engine, so things are looking up.Cheers, Chris W. (might even get out this weekend)
Click to expand...

You is lucky.

what I described was what actually happened to a Volvo MD11.
I suppose though part of the trouble was it did not stop .. it kept running on 1 cylinder until we stopped it.
 
VicS said:
You is lucky.

what I described was what actually happened to a Volvo MD11.
I suppose though part of the trouble was it did not stop .. it kept running on 1 cylinder until we stopped it.
Click to expand...

To be fair that's not a likely scenario on a single cylinder engine... ;)
 
Reminds me-

On petrol engines, the trick to change a broken (overhead) valve spring was to remove the plug at BTDC, feed in a couple of yards of cord/washing line through the plug hole, raise the piston by hand until it gently locked.

At that point, the compressed string held the valve/s shut and the spring could be swapped using a large cranked ring spanner to compress it to get the collets on . A two person job usually.

I want my 1500cc Anglia back!

Nick
 
penfold said:
The problem with that is that if the valve is only slightly bent, the spring will have enough closing force to give you compression to start,
Click to expand...

Sorry not the case, even a 2 degree bend will cause a leak sufficient to prevent starting.

Anyway the OP is reporting that the head is off the valve is not bent and hopefully all that is required is a new spring and gaskets.

I am keeping my fingers crossed for him.
 
Bukh reborn

Just a bit of a follow up.Engine all back together, changed the oil etc. Went down the river last night, felt like we had a new engine, more power, smoother,lets hope it lasts,lots cheaper than buying a new one! Cheers, Chris W.
 
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