Yanmar 315HP 6LPA STP

[CliffordGuernsey]

I had installed in my 44ft Ambassador Italcraft twin Yanmar engines costing some £41,000. In 146 hours and 315 hours both engines destroyed themselves when the diesel injection pump seized allowing free flow of fuel. The pistons hit the valves writing off both engines. The independent pump engineers say the pump relies on the diesel for lubrication. In both instances the fuel was analysed and the viscosity was normal. This suggests the injection pump is either not fit for purpose or the pumps were faulty. Has anyone else had a similar problem with this engine?

Has anyone come up with an approved additive that will increase the viscosity of the fuel passing through the Yanmar injection pump to solve this problem.

Yanmar paid for the first engine to be replaced but are not interested in contributing to the second engine as it is out of warranty! At 315 hours it is hardly run in. Anyone buying a new engine needs to consider the manufacturer's attitude when things go drastically wrong. I find myself on average needing to replace a Yanmar engine every 150 hours. Expressed another way costing me £130 per running hour!!!

 

[Latestarter1]

I had installed in my 44ft Ambassador Italcraft twin Yanmar engines costing some £41,000. In 146 hours and 315 hours both engines destroyed themselves when the diesel injection pump seized allowing free flow of fuel. The pistons hit the valves writing off both engines. The independent pump engineers say the pump relies on the diesel for lubrication. In both instances the fuel was analysed and the viscosity was normal. This suggests the injection pump is either not fit for purpose or the pumps were faulty. Has anyone else had a similar problem with this engine?

Has anyone come up with an approved additive that will increase the viscosity of the fuel passing through the Yanmar injection pump to solve this problem.

Yanmar paid for the first engine to be replaced but are not interested in contributing to the second engine as it is out of warranty! At 315 hours it is hardly run in. Anyone buying a new engine needs to consider the manufacturer's attitude when things go drastically wrong. I find myself on average needing to replace a Yanmar engine every 150 hours. Expressed another way costing me £130 per running hour!!!

Sounds like your independent engineer is part of your problem, instead of stating the blindly obvious he should take a serious look at you engine installation.

The Denso pump on your engines is licence made Bosch VE fuel pump, sold in huge numbers around the World. The LFP (Light Fuel Pack) was released around 1998 to ensure that pump could accomodate the new lower sulphur fuels which were coming out. Same pump is used on many makes of marine engine including many very popular Volvo models.

After the first motor failed did NOBODY think that somthing was seriously amiss with your fuel filteration set up? Just fit another engine and press regardless!

Second motor goes pop after the first warning.........Sad to say self inflicted.

Bosch/Denso VE pumps can handle zero sulphur fuel, however they cannot handle water contaminated fuel, the direct cause of your failure.

Barrus should have explained all this to you, however they may be partly culpable as their agent signed off the installation, which is why they are running for cover. However most likely that people you trusted and paid to perform the installation have dumped you in the expensive 'do-do'

Retain all your original paperwork, vital piece of evidence is the report from engine installer.

 

[Latestarter1]

Just a thinking through your failure mode...........

What rpm did engines make at WOT before you suffered catostropic failures?

 

[volvopaul]

Why do we hear this so often, it seems a lot fore engineering packages are born purely for profit and glamour to the dealer, not really what the boat owner expected as most owners paying out tens of thousands expect trouble free boating for at least the next ten years fir there investment and I'd quite agree.

I see many boats with the latest d4 engines fitted yet there primary filters are just about fit for a 1967 Massey ferguson tractor! Both fuel flow rate and ppm filtration capability, yet there sea trailed and signed off by the builders as there man has Volvo creditation and is an approved boat dealer, all bollox in my opinion.

I do really feel for you, have you also had the injectors tested as I've come across thar pump and engine that destroyed it's pump internals over a period of time, little metal particles from the pump eventually found there way into the injectors causing poor starting and White smoke this engine and pump I was told was prone to it.

 

[CliffordGuernsey]

See my email. But so others can see the reply the first engine was cold as we had been in a marina for 3 days. It happened on starting. The second engine was last June. We had crossed from Dartmouth to Guernsey at 3,300 RPM slowing a couple of times in the shipping lanes. As we approached we reduced to 2,500 and then to idle to put out the fenders. When I dropped to idle the engine exploded in a mass of black smoke and noise.
Does this help?

 

[CliffordGuernsey]

No, not tested the injectors. The engine was running absolutely perfectly prior to this. The previous winter the timing belt had been replaced along with the service. Panda Pumps inspected the pumps of both engines after the incident and said the plungers had seized on both occasions.

 

[CliffordGuernsey]

Thank you for your comments. The lawyers are currently looking at the whole thing. What I had not considered was that the fuel installation is at fault. It was not suggested when the first engine destroyed itself and it was not suggested after the second engine failed last June. A new engine was supplied and fitted costing around £20,000. Before starting the new engine the fuel was completely emptied from the tanks and fresh fuel put in but the installation of Racor filters remains the same but with a finer filter.

 

[andy59]

Sorry to butt in but i am struggling to understand why a faulty diesel pump caused the valves to connect with the pistons ( unless all the timing gear seized up) ?
Seem to remember the old 6LPs had valve sticking issues .

 

[CliffordGuernsey]

I am not an engineer but the way it was described to me is that with free flow of fuel the pistons go so fast that the valves cannot keep up and they hit. Some of the valves and pistons have melted. I would attach photographs if I knew how to do it!

The timing was not an issue. That was the first thing inspected after the incident as it had only recently been replaced. It was fine.

 

[Latestarter1]

Only fair to comment that I am in communication with OP.

Also fair to comment that Andy and Volvopaul have very valid comments. Which is reason behind adding my additional post regarding WOT.

Problem is that this and like many others here, is my bread and butter, however poor owners generally only have 'experts' advising them, generally named Tex to assist them...........Two gun Tex cos all they know about is shooting from the hip!

Let's dig faaaar deeper. Volvopaul is spot on, these type of rotary pumps suffer progressive failure mode when they have had water through them, white smoke and eventually poor starting. Valve contact caused by injector 'hosing' makes no sense either.

No point in conjecture without more facts. Last time I had access to MIVRIS (Worldwide engine production data) was many years ago and Toyota BJ engine was running at way over 150,000 units per annum. Arguement that fuel system not fit for purpose will never fly.

 

[CliffordGuernsey]

See Post 8 at 18.01

 

[Latestarter1]

I am not particularly suprised that fuel tested appeared 'normal' I hate that word, what lab carried out the testing?

Batch of contaminated fuel on earlier occasion could have caused slight spalling of pump rotor head which was not apparent at the time. Just think about it......If there are any statisticians out there even a serious product problem when you are building over 150,000 engines per annum affecting two engines within short time scale. We need to establish a common factor.

You mentioned Racor filters, what model and filter micron rating elements are you using?

Suprised that all attention focussed on the fuel pump, failue mode of theis type of PLN (pump line injector system) is contamination causing injector to 'hose' washing lube off the bores and piston failure. What were injector inspection reports? Normal rotary PLN pump failure is break up of rotor head leading to insufficient pressure to 'pop' the injector open, therefore on pump failure no fuel is injected.

The valve contact attributable to bore 'hosing' if that actually happened makes absolutely no mechanical sense.

Having looked inside a good few failed LP's I have some strong suspicions regarding your failures, however PLEASE PLEASE give us your WOT#'s this data is absolutely critical to giving you some sound advice and direction.

Marine Power are good guys, following replacement of the first failed motor they must have done sea trials so data must have been recorded.

At the moment based on what you are saying you can see from my questions that your failure could quite simply be viewed as indeterminate.

 

[Latestarter1]

Sorry to butt in but i am struggling to understand why a faulty diesel pump caused the valves to connect with the pistons ( unless all the timing gear seized up) ?
Seem to remember the old 6LPs had valve sticking issues .

Andy,
Having seen pictures of head and pistons, severe case of 'hosing' causing total melt down of piston crown, debris from melted crown have caused valve beat in.

Does not appear to be cylinder head valve recall issue, as well as the fact that hours are too low.

 

[andy59]

Andy,
Having seen pictures of head and pistons, severe case of 'hosing' causing total melt down of piston crown, debris from melted crown have caused valve beat in.

Does not appear to be cylinder head valve recall issue, as well as the fact that hours are too low.

Just out of interest ,how long would it take for enough temp to build up to melt a piston once an injector starts "hosing" , is it instant or a gradual build up at cruising rpm ?.

 

[Latestarter1]

Just out of interest ,how long would it take for enough temp to build up to melt a piston once an injector starts "hosing" , is it instant or a gradual build up at cruising rpm ?.

Remember propellers move boats not the engines, so it is all a matter of propeller loading on the engine.

Once injector tip has started to fail engine can soldier on with fuel droplets creating the typical Moonscape style craters on the surface of the piston, provided loading is light. all a factor of propeller loading, if the engine is heavily loaded or worse still overloaded, exhaust temperatues can rise in a matter of seconds to over 700 degrees C. As 660 C is the melting point of aluminum the plastic defomation of the piston crown is very quick. Hence my obsession regarding engine loading and WOT rpm.

 

[spannerman]

The odds of two engines having the same failure in the same boat are pretty high, espescially with Yanmars which are very reliable units. So I think you have to consider what could be a common demoninator, that is your boat, tanks and fuel supply to the engines assuming they have an identical setup.
As VolvoPaul stated you have to make sure the prefilter is the correct spec for the application.
We frequently see D4 and 6 motors in production boats with totally inadequate prefilters and in the case of Hydrolift boats no prefilter at all!
Yet Volvo clearly state in their installation book what spec the filtration must be to have an approved insatllation.
I am pretty sure Yanmar also publish installation specs too.
If you can prove the installation was not carried out correctly by so called 'proffesionals' you may have a stronger case.
You have to get to the bottom of it otherwise you can't be sure that it won't happen yet again.

 

[Latestarter1]

The odds of two engines having the same failure in the same boat are pretty high, espescially with Yanmars which are very reliable units. So I think you have to consider what could be a common demoninator, that is your boat, tanks and fuel supply to the engines assuming they have an identical setup.
As VolvoPaul stated you have to make sure the prefilter is the correct spec for the application.
We frequently see D4 and 6 motors in production boats with totally inadequate prefilters and in the case of Hydrolift boats no prefilter at all!
Yet Volvo clearly state in their installation book what spec the filtration must be to have an approved insatllation.
I am pretty sure Yanmar also publish installation specs too.
If you can prove the installation was not carried out correctly by so called 'proffesionals' you may have a stronger case.
You have to get to the bottom of it otherwise you can't be sure that it won't happen yet again.

'If you can prove the installation was not carried out correctly by so called 'proffesionals' you may have a stronger case.
You have to get to the bottom of it otherwise you can't be sure that it won't happen yet again.'

Thank you Spannerman, you can see exactly the direction in which I trying to steer the OP.

However the fuel system experts he is trusting are leading him up the garden path, by confusing typical common rail failure mode with pump line injector failure. I have heard it all before veiled suggestions that Denso pump not fit for purpose, or part of a bad batch, none of it washes.

Contaminated fuel has taken out the injector nozzle and damaged the pump, the 'experts' are saying pump siezed first due to lubricity issues. I would be interested to know how a siezed or partly siezed rotary pump producing squat all line pressure enough to cause injector 'hosing'. Suggest too many people ducking and diving in the hope that the **** does not stick to them.

All that is required is for somebody to look at the big picture identify shortcomings in the vessel installation which caused the failure and attempt to obtain some redress from the people who slung this poor guy under a bus. Not sure who led the charge on this repower however I would certainly not have specified Yanmar LP's for this application however that is another issue.

 

[tinkicker0]

I'm struggling to see how a Bosch VE pump plunger seizing up would melt the pistons, transfer pressure is probably only about 40psi and not enough to lift the injector needles.

Seen plenty of VE failure modes, usually after someone has put a bit of petrol in em resulting in spalling of the cam plate and manifesting itself in either the stop solenoid sticking with metallic particles causing non start or non stop, the cold start advance solenoid jamming causing white smoke when cold, or indeed once saw a pump body blow all its o rings due to overpressure as the cold start advance plunger pressure relief valve jammed with crud behind it.

Only way I can visualise it is if the plunger suddenly wore itself out, the distributor head wore out also and an injector tip fell off and the needle jammed. Highly unlikely.

Someone is telling the OP porkies methinks.


Also, if it is fuel erosion, the OP needs to insist on the manifolds and turbos being replaced too. Molten ally will be deposited everywhere down the manifold and in the turbo. A big lump breaking off the inside of the exhaust port / manifold and dropping into the turbo will ruin your day.

I see this type of damage every week.

 

[CliffordGuernsey]

Completely independent injection pump engineers have inspected the injection pumps after both failures and said they both failed due to lack of lubrication. The fuel analysis on the first engine was O.K. The pump engineers said they could see nothing wrong with the fuel in 2nd failure pump but recommended the fuel should be analysed. An independent engineer recommended by Barrus who inspected the second pump and saw the fuel analysis reports said it was the engine to blame. The independent fuel analysis reports say the viscosity of the fuel was within acceptable limits on the first failure and the analysis of the fuel before it passed through the engine filter was a little higher than target (ISO 18/16/30) on the second engine. The fuel in the pump was not analysed. It is assumed that by the time it passed through the second filter it will have been OK. We had absolutely no starting problems and the engines ran smoothly and well right up to each failure with only the usual smoke on starting.

Based upon these facts I think it reasonable to take it that the diesel filter system is working satisfactorily. I would have expected a positive pro-active response from Yanmar and E.P.Barrus to work with me to establish exactly what has caused two of their engines to fail. Instead they have simply turned down my claim offering no explanation.

I have written a magazine article that includes all the issues raised on this forum. I gave Yanmar/Barrus 10 days to say if any facts were incorrect. They did not comment so I think it is reasonable to assume they agree the facts are correct.

I cannot speak highly enough of Marine Power in The Hamble who replaced my first engine in 28 days. Yanmar/Barrus eventually paid in full without admitting liability.

Herm Seaway Marine in Guernsey replaced the second engine and had me back in the water in 18 days. It is a great shame that me, the customer, and the local Yanmar dealership do not appear to get the support we deserve from E. P. Barrus and Yanmar.

 

[volvopaul]

It's a very small world as Peter owner of marine power offered me your old engine a few months back, I personally deal most of the time with Ian at dave Crawford marine when I'm asking for info on yanmars.

As both engine have failed there Must be a common fault with either both engines or the boats installation, maybe the running angle is too great and the engine is inclined too far? I'm not sure about your boat but a 44ft boat in my opinion should not have been fitted with a 24 valve hi revving motor, it should have had a slower unit with more guts lower down.

I think you need to tell me what pre filters you have and what size of fuel lines you have, one thing that does spring to mind instead of poor lube quality fuel is high fuel temp at the pump, yes I know they have a fuel cooler but some boats I come across like some sealine have 3 tanks and the central one that the engines draw fuel from is usually the small one and both motors suck from it, so maybe that's one of your answers, I realise you have shared some private info with latestarter I'd like to hear it too, if only to assist me in the future as I do many re engine projects, some new some used units etc.

Out of interest what motors were in the boat before the yanmars on what gearbox and what running angle?

I'm not surprised barrus have reacted that way, some years back I re engined a broom 345 from mercruisers to yanmar 6pm 12 valve units, and to be honest they totally useless on the phone when I asked them for help and info, even to the point they couldn't answer anything beyond what was on the spec sheet for the engines, at the outset of the project I'd father have fitted volvos because at least there is someone at Watford who actually knows the product.

As the motors were supplied by an eu country I'm sure you should be covered by eu law and the 6 year warranty that so many people don't ask about when parts fail prematurely, I recently helped a Volvo owner with a 4 year old targa get new steering rams and a pump due to water ingress in the whole system. So I'm sure your legal team will be on the facts over this one.