piston broke d4 300 at 420 hours

[Orthop]

Hi
a piston broke on my stbd engine at 420 hours, its the 8th season, bought the boat from new, made all services and more...
The mechanics in Italy told me, that I have 2 options:
1. new motor block
2. restored motor block, also made by Volvo
There is also a warranty for the restored block, Volvo says on their website, and the say the overhold engine is as good as new...?
Can anyone give me some advice. Any ideas why the engine broke at 2800 rpm at 25 knots...? No information on the instruments before...
Greetings from bavaria
K

 

[volvopaul]

Hi
a piston broke on my stbd engine at 420 hours, its the 8th season, bought the boat from new, made all services and more...
The mechanics in Italy told me, that I have 2 options:
1. new motor block
2. restored motor block, also made by Volvo
There is also a warranty for the restored block, Volvo says on their website, and the say the overhold engine is as good as new...?
Can anyone give me some advice. Any ideas why the engine broke at 2800 rpm at 25 knots...? No information on the instruments before...
Greetings from bavaria
K

You would have to give more information like did it overheat , loose oil pressure , loose its coolant or oil.
Engines just don’t blow up for no reason.

Did the engineers take readings from the vodia before they dismantled it

 

[Orthop]

Hi,
Thanks for the reply.
No overheat, no loosening of oil pressure or coolant or oil. Just reduction of rpm and black smoke at the stern with oil below the stbd. engine. No fault sign in the display at anytime. The Vodia said Zylinder 3 without working... (Cylinder 1: 100%, C2 96%, C3 0%, C4 89%)
Have also pictures from the cylinder and the piston, but problems to load them up. The mechanics detected a 0,5mm mismatch of the injector in comparism to the other injectors. Perhaps a Problem with the injector. Paul can I PM you to show you the pictures?

 

[Bbroomlea]

Water in fuel? These engines do not like water at all. Did the piston crown hole?

 

[Orthop]

You would have to give more information like did it overheat , loose oil pressure , loose its coolant or oil.
Engines just don’t blow up for no reason.

Did the engineers take readings from the vodia before they dismantled it

Hi,
Thanks for the reply.
No overheat, no loosening of oil pressure or coolant or oil. Just reduction of rpm and black smoke at the stern with oil below the stbd. engine. No fault sign in the display at anytime. The Vodia said Zylinder 3 without working... (Cylinder 1: 100%, C2 96%, C3 0%, C4 89%)
Have also pictures from the cylinder and the piston, but problems to load them up. The mechanics detected a 0,5mm mismatch of the injector in comparism to the other injectors. Perhaps a Problem with the injector. Paul can I PM you to show you the pictures?

 

[Orthop]

Hi,
Thanks for the reply.
No overheat, no loosening of oil pressure or coolant or oil. Just reduction of rpm and black smoke at the stern with oil below the stbd. engine. No fault sign in the display at anytime. The Vodia said Zylinder 3 without working... (Cylinder 1: 100%, C2 96%, C3 0%, C4 89%)
Have also pictures from the cylinder and the piston, but problems to load them up. The mechanics detected a 0,5mm mismatch of the injector in comparism to the other injectors. Perhaps a Problem with the injector. Paul can I PM you to show you the pictures?

 

[Portofino]

What’s “broken “ ring or hole in piston ?

Injector tips burn off with water in the fuel .The Hydrogen from the water burns the tip off , hence 0.5 mm missing .
Hosing leads to excessive heat and a hole is burnt in the pistons = black smoke and excess oil pressure it’s forces out . But no alarms ?
Water gets in through the tank pipes especially a weak o ring on the filler .
No alarms or codes is worry if it’s was water ?

“Broken “ could be a cracked ring (s) again a pic would save me a typing 1000 words

Overloading .How clean where the props on that trip out . Excessive EGT ,s ?
Could you have gone faster than 2800 rpm on the day ? We need to know this as a process of elimination.

Agglomerations - how do you how if the oil has been actually changed along with the filter ? If the oil is old a ring the bottom one could have cracked .

Suppose a massively hosing injector could have suddenly cooled a ring and the thermal stress cracked it , again no pic to see which ring if it’s a ring at all ?? Likely the top ring has “ broken “
Normally a faulty injector from dirt in fuel .( not closing ) over fuels and the excess heat from too much melts alloy pistons .

 

[[2068]]

Sounds like more than a broken ring if the oil has decided to leave the engine.

 

[volvopaul]

This is typical injector failure , hosing no spray pattern leading to nozzle fully open . Soon as this happens it dumps the full rail pressure into the cylinder causing piston failure .
Sadly the outcome of a common rail injection system.
Hope they replace all injectors .

 

[Orthop]

What’s “broken “ ring or hole in piston ?

Injector tips burn off with water in the fuel .The Hydrogen from the water burns the tip off , hence 0.5 mm missing .
Hosing leads to excessive heat and a hole is burnt in the pistons = black smoke and excess oil pressure it’s forces out . But no alarms ?
Water gets in through the tank pipes especially a weak o ring on the filler .
No alarms or codes is worry if it’s was water ?

“Broken “ could be a cracked ring (s) again a pic would save me a typing 1000 words

Overloading .How clean where the props on that trip out . Excessive EGT ,s ?
Could you have gone faster than 2800 rpm on the day ? We need to know this as a process of elimination.

Agglomerations - how do you how if the oil has been actually changed along with the filter ? If the oil is old a ring the bottom one could have cracked .

Suppose a massively hosing injector could have suddenly cooled a ring and the thermal stress cracked it , again no pic to see which ring if it’s a ring at all ?? Likely the top ring has “ broken “
Normally a faulty injector from dirt in fuel .( not closing ) over fuels and the excess heat from too much melts alloy pistons .

Yes could have gone faster than 2800, oil was changed before the winter storage, also the filters, the oil was new...
I have had a water alarm 2 years ago. I stop the engine immediately and did what the d4 manual describes in that case plus change of the filter. I always control the separ filter. Had no following alarm. Afterwards I had a professional tank cleaning from the German engineers from "MICROFILTERTECHNIC".

 

[volvopaul]

Yes could have gone faster than 2800, oil was changed before the winter storage, also the filters, the oil was new...
I have had a water alarm 2 years ago. I stop the engine immediately and did what the d4 manual describes in that case plus change of the filter. I always control the separ filter. Had no following alarm. Afterwards I had a professional tank cleaning from the German engineers from "MICROFILTERTECHNIC".

A photo of the piston crown will tel if it’s a hosed injector

 

[Orthop]

This is typical injector failure , hosing no spray pattern leading to nozzle fully open . Soon as this happens it dumps the full rail pressure into the cylinder causing piston failure .
Sadly the outcome of a common rail injection system.
Hope they replace all injectors .

Yes we change all injectors port and stbd.
Plan now is to change the block. Is the overhauled block from Volvo as good as a new one? The difference is 6000 €. They give also a 2 year warranty for the restored engine, with the possibility to by more...
A BMW engineer told me, they use nearly always overhauld engines by the cars, if a motor brakes. And there is less danger of stress cracks in the older materials...

 

[Orthop]

I will try to load up the picture...

 

[Orthop]

 

[rafiki_]

Yes we change all injectors port and stbd.
Plan now is to change the block. Is the overhauled block from Volvo as good as a new one? The difference is 6000 €. They give also a 2 year warranty for the restored engine, with the possibility to by more...
A BMW engineer told me, they use nearly always overhauld engines by the cars, if a motor brakes. And there is less danger of stress cracks in the older materials...

It depends how well the reconditioning is done. This means full checking and measuring of the block and any bearing journals. Then using OE parts to rebuild. Helpful to know the engine is hot tested before leaving the factory.

 

[volvopaul]

It depends how well the reconditioning is done. This means full checking and measuring of the block and any bearing journals. Then using OE parts to rebuild. Helpful to know the engine is hot tested before leaving the factory.

D4/6 blocks are scrap , no internal parts available.
Volvo sell a short engine it’s the only way .

 

[Orthop]

D4/6 blocks are scrap , no internal parts available.
Volvo sell a short engine it’s the only way .

Thanks for all replys. The new stbd. engine is running already...The injectors of the other non port broken engine were tested at the BOSCH center, and they said the are ok. Should I replace them although or not?
Is there a limited life of some injectors. Should they be replaced in a certain period?

 

[Portofino]

I’d be minimising the chances of another failure.

1- Robust WIF - water in fuel elimination - review the OEM ( boat show life only filtration) consider a centrifugal filter like a racor with WIF alarms / probes , and visibility + easy drain cock .

2- minimising excess EGT . Basically running with clean props ensuring ( what ever - how ever ) they are clean every time .

Your injectors have “passed “ .New will fail with WIF and excess EGT running .

I doubt you where unlucky , you make your own luck with high speed diesels in boats .

 

[Orthop]

Thanks Portofino,I think I will use paddles in the future,
P:S. Have Separ with WIF alarms on both engines...
What about additives?

 

[volvopaul]

I’d be minimising the chances of another failure.

1- Robust WIF - water in fuel elimination - review the OEM ( boat show life only filtration) consider a centrifugal filter like a racor with WIF alarms / probes , and visibility + easy drain cock .

2- minimising excess EGT . Basically running with clean props ensuring ( what ever - how ever ) they are clean every time .

Your injectors have “passed “ .New will fail with WIF and excess EGT running .

I doubt you where unlucky , you make your own luck with high speed diesels in boats .

I am afraid Porto you will not get a high EGT on any D4 or D6 series Volvopenta engine .
The engines EVC system is constantly monitoring the propeller load by comparison of throttle position ,rpm, fuel burn, fuel temp, water temp, boost pressure and inlet air temp. It’s mainly the air inlet temp that fuels the engine.
This is all built into the ecu to protect the engine, that is the rrason why after a few months into the season the engines will not pull there full rated rpm , this is very particular on the larger IPS boats , the Princess V48 mark 2 is a pr8me example of utter dissatisfaction for most owners .
There is also an exhaust gas probe fitted just after the water injection elbow for safe measures .
Looking at the picture of the failed piston the marks do not comply with a failed injector which when failed gives momentary full fuel before the rail pressure drops shutting down the engine immediately.
The crack could be from a latent defect , in a lot of cases carrying out a post Mortem on a wrecked engine is very difficult, I have over the years acted as an expert witness examining failed recently new built or reconditioned engines .
it’s a terrible job to be involved in , they go on sometimes for years when really all the owner wants is his boat back in the water .

As the OP has stated the injections are fine and the crack is very visible I’d be going down the latent defect route .
The only other possibility is that there was some previous damage to the piston not detected in a previous ownership, which has now reared it’s ugly head.
The standard engine secondary fuel filters Water in fuel sensor is more than up to the job , it flashes up straight away reducing engine RPM placing the motor into limp mode.
Go and enjoy your boat Mr OP .