What would you check, change or refurbish on 11 year old, 1,250 hours D-12's?

[Nick_H]

We had a couple of engine issues during the last trip (corroded exhaust elbow and leaking raw water pump) which though minor, caused some disruption to the holiday waiting for parts and availability of an engineer. I'd like to try and reduce the chances of the same happening next year by doing some refurb work on the engines over the winter in addition to the normal servicing. So, what should I refurb on a D-12 engine of this age/hours?

I've noticed a bit more soot on the transom of late, and a bit of smoke in our wake. The air filters were new after the exhaust leak, so what else could cause this? Should I have the injectors serviced? As far as I know they haven't been done previously. Could it be valve clearances, these have been done as per the service schedule but may be due again now. Engines seem to run fine and turbos kick in OK, but I'm possibly slightly down on WOT.

Is it time to replace all the fuel hoses, or is it enough to check them for condition, likewise the water hoses and exhaust hoses. Is it worth taking the alternators, starter motors and/or turbos off and having them re-furbished? I've had the seals changed on the raw water pumps after the problems this year, but do they need a more general overhaul?

Also, I've noticed that the water injection elbows each have two mild steel bolts in a raised area that has been ground flat, which are heavily corroded. They only seem to be blanking off some holes (used for EGT sensors?), and the rest of the elbow must be stainless or alloy as it has no signs of corrosion. If I can get these out can I re-fit with stainless bolts to stop them corroding again?

Any other things I should check, refurb or replace? Any thoughts/advice much appreciated.

 

[jrudge]

Cleaning the heat exchangers? Alternators - I suspect the only wear part is the bearing, and you have 2 alternators ... so personally I would leave it unless making a noise. Starter .. not used often ( i.e. 10 secs each time you use it) and again the wear item is probably the bearing (other than the whole thing going up in smoke).

Hoses. Are they cracked? If so probably ... depending on how much of pain they are to replace.

Whilst not a D12 Jimmy the Builder will have a perspective on this given his recent winter project!

 

[jfm]

We had a couple of engine issues during the last trip (corroded exhaust elbow and leaking raw water pump) which though minor, caused some disruption to the holiday waiting for parts and availability of an engineer. I'd like to try and reduce the chances of the same happening next year by doing some refurb work on the engines over the winter in addition to the normal servicing. So, what should I refurb on a D-12 engine of this age/hours?

I've noticed a bit more soot on the transom of late, and a bit of smoke in our wake. The air filters were new after the exhaust leak, so what else could cause this? Should I have the injectors serviced? As far as I know they haven't been done previously. Could it be valve clearances, these have been done as per the service schedule but may be due again now. Engines seem to run fine and turbos kick in OK, but I'm possibly slightly down on WOT.

Is it time to replace all the fuel hoses, or is it enough to check them for condition, likewise the water hoses and exhaust hoses. Is it worth taking the alternators, starter motors and/or turbos off and having them re-furbished? I've had the seals changed on the raw water pumps after the problems this year, but do they need a more general overhaul?

Also, I've noticed that the water injection elbows each have two mild steel bolts in a raised area that has been ground flat, which are heavily corroded. They only seem to be blanking off some holes (used for EGT sensors?), and the rest of the elbow must be stainless or alloy as it has no signs of corrosion. If I can get these out can I re-fit with stainless bolts to stop them corroding again?

Any other things I should check, refurb or replace? Any thoughts/advice much appreciated.

Nick, this corresponds to 40k miles in a lorry, so the basic mechanicals should be fine and D12 is far from a soft engine. My old sq58 had 1500 hrs when I lost touch (it went to turkey) and was fine. Alternators don't matter because you have 2 plus a 230v charger. Starter motors should be ok. Valves are worth checking because you have the earlier series of rockers that need adjusting more carefully than the later ones. If hoses look ok then they are ok. Anything that sniffs seawater (elbows+raw pumps, as you already know) needs attention. Sternglands - do you have the second seal ready to slip on? If yes then leave them alone till needed.
Domestic freshwater pump failure could ruin a holiday and they are a bit cheapish to begin with, so maybe get a spare.
Time for set of new batteries?
The rusted EGT plug bolts might be mild steel due to npt thread or something and they couldn't easily get that size in s/s. Worth changing to s/s, as you have time to source s/s bolts in non M sizes

 

[spannerman]

In addition to the valve clearances, the injector clearance needs checking/adjusting at 1,000 hrs as they are driven from the camshaft same as the valves.
If its getting a bit smokey then it could be worth having the injectors serviced then all the work is done for some time.

 

[MapisM]

I'd like to try and reduce the chances of the same happening next year

Easy, plenty of time to swap the whole thing for something brand new, pushed by a couple of engines with 10, or even better 12 cylinders each side.
You know that's what you want, dontcha?

 

[Deleted User YDKXO]

+ 1 for removing/cleaning heat exchangers including any on the gearboxes. I was plagued by minor coolant leaks from the overflow pipes from the header tanks last season but since I had this done, the leaks have disappeared. Slightly disagree with jfm on alternators. A failing alternator can shut down an engine because it can lead to battery discharge and if the voltage drops too much, the stop solenoid will shut and cut off fuel to the engine. This has happened to me. Rather than refurbish, why not just carry a spare and a spare starter motor for good measure? As jfm says, 1250hrs is not much (some of the construction machines we sell do that in 6 months!)

 

[Nick_H]

Thanks all. Heat exchangers were cleaned two years ago at about 1,000 hours, and were quite clean when stripped down. I may treat with rydlime over the winter but I don't think there's any need for another strip down yet. I'll get the valves checked even if not on schedule, and will have the injectors checked/adjusted/serviced.

There are some small cracks in the raw water hoses so I'll change those, and i'll carefully check all the other hoses for any signs of deterioration, and change any that look at all suspect. I fitted new batteries this year, so they will be fine, and I already have spares of almost every domestic pump on the boat because they seem to go so often, in fact i've replaced the fresh water and grey water pumps at least five times whilst i've had the boat.

Any view on the turbos? I've previously been advised that if they ain't broke don't fix 'em, but then I've also heard of turbo problems spoiling holidays. I believe that D12's have electronically governed waste gates, which I assume means they don't need adjusting(?), but do they wear out or suffer deterioration? Also, conscious of the problems Bart has experienced, are there any checks or adjustments required of the camshaft damper, or is this done routinely as part of the annual service?

 

[MapisM]

conscious of the problems Bart has experienced, are there any checks or adjustments required of the camshaft damper, or is this done routinely as part of the annual service?

You mean the crankshaft damper, I suppose?
Fwiw, I spoke of what Bart experienced on BA with my Cat authorised service, and not only they told me that they never heard of a similar fault on any yellow engine, but also confirmed that there's nothing requiring any service.
That pretty much depends on each engine, I suppose - better wait for a VP expert to confirm...

 

[MapisM]

A failing alternator can shut down an engine because it can lead to battery discharge and if the voltage drops too much, the stop solenoid will shut and cut off fuel to the engine.

Well, you could still run the genset+battery charger anyway. I for one wouldn't keep a spare alternator onboard.
Otoh, I did have one starter motor which occasionally got stuck, several years ago.
But I cured that with a hammer, rather than by replacing it with a spare - which needless to say I didn't have...
Btw, funnily enough, it never happened again after that season.
I suppose it had enough of being hammered and learnt the lesson! :encouragement:

 

[BartW]

If its getting a bit smokey then it could be worth having the injectors serviced then all the work is done for some time.

+1
changing injector nozzles after +1000 hr's made a big improvement on soot and smoke emission

 

[Nick_H]

+1
changing injector nozzles after +1000 hr's made a big improvement on soot and smoke emission

That's good to know, injector service is on the list.

 

[jfm]

Well, you could still run the genset+battery charger anyway. I for one wouldn't keep a spare alternator onboard.

Yep, my thought exactly. If we are talking about a spoiled holiday, an alternator wont do it. you just start the genset and charge the engine battery that way, or indeed swap a few cables and run that engine off the house batteries or the other engine's batteries, both of which are being charged by the other alternator. (I have in fact being doing this since mid way thru my Mallorca trip this season, due to a failed alternator regulator!)

 

[Latestarter1]

That's good to know, injector service is on the list.

Sorry guys NO NO NO, leave the unit injectors well alone, experience with cold running PLI injectors is no comparison, unlike Mangrenade D12 is an extremely robust base engine, likewise turbo if installation is sound will be fit to trot for many more hours.

Never change EUI unless the diagnostic tool tells you to and then ONLY change that injector never the whole lot.

As to the rest Volvo guys will have their call.

 

[jfm]

Interesting comment, and nicely £££ saving so more power to your elbow Latestarter!

When the diagnostic tells you to fix an injector, exactly what parameter or combo of parameters is it using? I can imagine it uses exhaust data to decide that there is bad fuel burn, but it must be checking some cylinder specific parameters to know that a particular injector is busted.

 

[Deleted User YDKXO]

Well, you could still run the genset+battery charger anyway.

Don't you think that was the first thing I did Nope that doesn't work or at least it didn't work on the AZ46 on which this happened. I guess there must have been some kind of system which isolated the charger when the engine alternators are charging. Yes I could stop the engines and start up the gennie to charge the batteries (not something you want to do in the open sea) but as soon as I started the engines again, the batteries discharged and the (starboard) engine stopped. Btw this was Ibiza in August and it took 4 days to diagnose the problem and find out there wasn't a spare alternator on the island and a further 2 days to ship one from the UK. Not a holiday stopper but driving around on one engine most of the time was a PITA

Ever since then I've carried a spare alternator onboard. Which reminds me. I must buy one for this boat

 

[jfm]

Which reminds me. I must buy one for this boat

Don't! The problem was the Azi, not anything else. The Freti will likely be much more sensibly wired. As I say, I have had a non working alternator on one engine for the last few months and it is well down my list of things to deal with

 

[MapisM]

100% agreed, I also wouldn't bother.
M, the AZ46 must have had some weird connection, in your boots I'd check the F630 arrangement first.
My bet is that there's a much easier/quicker way to keep her going with a dead alternator without replacing it - which btw is also something you don't want to do in open, possibly rough sea, and in a hot e/r.
Glad to have a look at your electrical scheme together, if you wish.
Incidentally, coming to think of it, I wanted to ask you a favour and check if you have in your manuals anything related to those red current displays (Amperes and Volts) located on the electrical panel.
In fact, they are very similar to the ones I have on my boat, one of which just went blank, and I have no documentation at all about them.

 

[Latestarter1]

Interesting comment, and nicely £££ saving so more power to your elbow Latestarter!

When the diagnostic tells you to fix an injector, exactly what parameter or combo of parameters is it using? I can imagine it uses exhaust data to decide that there is bad fuel burn, but it must be checking some cylinder specific parameters to know that a particular injector is busted.

JFM
As usual your simple question demands a somewhat comprehensive reply as well as a bit of a history lesson….
The EUI (Electronic Unit Injector) has its roots in North American emissions combustion strategy, ‘let the fuel find the air’ as opposed to the European ‘let the air find the fuel’ approach.

By the late 1970’s the once iconic Detroit Diesel Division of General Motors was on a path to two stroke oblivion and GM no longer had any real commitment to trucks or Diesel engines having made a half-hearted bid for MAN and latterly tried to purchase Leyland from Thatcher Government.
Despite the storm clouds Detroit beavered away and produced the excellent four stroke Series 60 heavy duty diesel engine using their own in house EUI system. The Detroit EUI was designed to be a B50 life to overhaul component.

In the same time frame Lucas UK before being destroyed by the ego of one man saw the US as an opportunity and was involved with CAT to develop another EUI.

Bosch were putzing around with their own EUI and having real problems and going nowhere with hindsight we now know Volvo and Scania were breathing down their neck.
The new DD Series 60 suddenly started running rings around CAT and Cummins not only in the US but Australia and South Africa despite everybody’s caution regarding the then new electronic engines.

Despite the success of the Series 60 GM suddenly sold Detroit Diesel to Roger Penskie. Before Penskie became overwhelmed by DD he had to cash some chips in, up steps Mr Bosch and purchases the fuel systems division of DD just to get their hands on the lovely Detroit EUI. Bosch dump their own crummy EUI, adopting and refining their acquisition as a new key Bosch product.

The success of EUI’s is that they work on the basis of power balance or put another way cylinder contribution therefore a new 500 hp diesel engine will provide consistent performance up to very high hours even one or two injectors are not pulling their weight by the other injectors simply compensating. It is only when an injector falls below a certain cylinder contribution level or fails completely that the ECM/ECU shouts for help.

Pump shops do not generally have EUI functionality testers therefore best approach is let the engine tell you if any EUI’s not pulling their weight with a cylinder contribution test with the electronic service tool. If one or two cylinders found not to be up to scratch simply change out those injectors.
Hand on heart the only way to screw up an EUI is with contaminated fuel.

 

[Bandit]

Think power train not only engines.

get a good engineer who is well up to speed on your engine with good training to go through engines witha fine tooth comb and work up a job list with you.

My bend before injection elbow failed on starb engine with corrosion, injection bend in poor condition well corroded up, so changed both bends before, both water injection bends, flexibles and clamps. These failed after 12 years so should be good for another 10.

How old are your stern seals, this is a show stopper if over 6 years old and drip less, change seals my preference is Tides Marine with a spare seal on each shaft so you can change a seal without pulling shafts back.

While you are changing stern seals drop the shafts and change out cutless bearings, Lapp the prop back before refitting.

Check engine mounts carefully and realign engines.

Remove water fed to stern seals from engine to seals and inspect, clear out or replace also prove, should provide over four litres per side at tick over also check cross over from one seal to the other, mine were blocked. This is an annual job.

Fuel condition, what are your filters like, if you have a problem sort it, I have sumps in each fuel tank and strip them each year with a Pella pump to remove water and crud, not much but better out than in. If no sump or drain cock what about a fuel polish, probably worth It after 11 years. A week or more before polishing Treat with a good biocide such as Grotamar 82 shock treatment dosage, give the boat a bit of a run at sea to shake it all up before polishing.

 

[Latestarter1]

Good call on injection elbow inspection before they fail and take out the turbocharger.