OT: Marine diesel engine smoking.

Over fueling, worn injectors, dirty injectors, injector pressure,

Ok thanks.

So, the middle two could (potentially) be tested by out local diesel place.

T i m

Try adding some additive first such as Millers Diesel Sport 4. It also depends what he is running it on. If it is proper diesel then it's having too much injected. If he is using red diesel or green diesel or "heating oil" then it will smoke more. I wouldnt even begin to offer him any help, whatever you do will never be right and if anything else goes such as a lightbulb in his house - it will be your fault. Diesels often smoke badly when too much diesel is injected, that's why you can spot people using those crappy Diesel Tuning boxes on their engines. Belching black smoke and knackering EGR valves! There are a few marine diesel forums about - they would give you all the advice in the world if you posted the engine details. Most have common problems just like car engines. Why would he have the parts to repair it if he didn't know what was wrong? Did someone guess or tell him what was wrong and then refused to touch it, or couldn't guarantee the diagnosis was correct.

Ok, easy and worth a go.

Understood. I think it's likely to be 'std' road diesel.

No, he's not like that Roger. He would be very grateful for my time whatever the outcome.

Not good. Never been a 'tuning' man myself, working on the basis, that for my simple use, the manufacturer probably knows best. ;-)

Ok thanks, I'll have a look around.

I guessed as much and hence why I asked here. He suggested the reason marine engines were commonly used for this role (high pressure water pump) is because they were designed to sit at a reasonable load for a reasonable time.

Probably. (Although I'm not sure about the refused to touch it bit, it may just have been to expensive for such unpredictable results etc).

Like I said. I feel that if it's not looked at as a 'project' he would simply bin it and buy something else. FWIW it looks like new and is mounted on a very nice galvanised road trailer and behind it a nice hydraulic crane. ;-)

Thanks for the thoughts / tips though, I'll run through them with him and see if any of them have been tried already.

T i m

I would generally suggest that the injectors are the first port of call with smokey diesels, as they are the easiest to deal with. However, you're saying that the smoke is blue, which points to oil burning (rings and/or valve stems - but he's done valve stems so it's not that). Try doing a compression test, although if the engine starts alright this may not be conclusive. Would you or your friend know what the readings should be, anyway?

Rob Graham

This could be very expensive to fix. useful start would be this book: Marine diesel engines: maintenance, troubleshooting, and repair By Nigel Calder

There are sites on the net with manuals for most engines, so first establish exactly what it is and go from there.

You may find that it is built like a motorbike engine and the barrels are removable.

It may just need rings or may need new barrels/piston assys.

I would stay well clear, but if you like a challenge and someone else is paying..............?

Completely Ot but some guys with experience of often very old diesels and with rafts of information about oddball diesel engines are the guys over at

Try the forum for advice, you'll need to sign up and put a real name in your sig, but other than that they are all very well clued up and many have access to lots of information and parts for weird and wonderful diesels.

Kip

I like the logic, thanks. ;-)

FWIW (and I'm not suggesting you are suggesting such etc) but I think this particular lump is 1) fairly modern and 2) fairly traditional.

Having said that I was a bit surprised to find out it had three separate heads (VW Beetle principal) so each cylinder could be dealt with independently (presumably and to some degree).

Whilst I haven't done much on diesels I've done quite a bit on engines of all types and sizes and given either some accurate machine-specific guidance or more general help and a decent manual I'm happy to have a go at anything, especially if it's a 'last resort' sort of deal (as this would be).

Coincidentally the same guy was having issues with a V twin petrol pump (smaller scale to the diesel setup) and I guided him to a diagnosis of a bad plug / burnt valve. Turned out to be the former luckily. ;-)

He gave me an old iPod Nano (I asked if he had one he didn't want and that I could 'play with' (as I was looking for a music solution for my elderly Dad). It needs a new back light (I think it comes with a new screen module) and for under a tenner I'll give it a go. I don't need a 4G mp3 player so if it all goes pear shaped I've lost little but may just learn some more stuff. ;-)

Cheers, T i m

..assuming they have the proper test equipment which many don't.

I believe this lot do:

... well, they seem to be able to take a set of injectors from a car that's not running well and give them back and the car then runs fine, so they must be doing *something*. ;-)

A mate uses them for all his diesel stuff (I don't think they do petrol injection work ... I would have thought they would have done both but maybe the systems are miles apart?) and pretty sure is happy with them.

Armed with more facts about the engine in question I would be inclined to ask someone who knows that particular model / range before I would consider going near it myself. Mainly because whilst it could be considered 'interesting' (for different ideas of 'interesting') to have a go at sorting it I'd like to know I had a fighting chance of making it better before I did.

Cheers, T i m.

Basically what they need is the equipment to carry out both leak tests and spray pattern testing.

Which most diesel pump suppliers have. They're not particularly expensive.

Diagnosis starts the same way as with any other engine. The basics!

1) Compression test. Obviously disable all fueling first, you don't want it starting up with a comp tester in it and of course you need a diesel engine comp tester as a petrol one would blow into tiny pieces. Even if you don't have a spec for the pressure it will be valuable to see if all cylinders read the same. Any major difference clearly points to an issue. A leakdown test would help pinpoint any issues the comp test finds. More detailed info is on my web site. 2) Cam timing. Even without a spec you'll expect inlet full lift to be a similar amount ATDC as exhaust full lift is BTDC. If anything the cam could be up to 3 degrees advanced i.e. inlet full lift up to 6 degrees less ATDC than exhaust full lift is BTDC. Anything much outside that indicates it hasn't been set right. On a cooking diesel engine I'd expect numbers around 110 to 114 degrees, in each case ATDC and BTDC.

3) Cam lift on each lobe checking that all inlet lobes have the same lift as do all exhaust ones even if that's a different figure.

If the basic engine health is ok then you're into fuel pump condition and timing and injector condition. If the basic engine health isn't ok it's pointless looking at other areas until the faults have been corrected. It would also be silly to remove any major components without getting valve seats recut, guides replaced, bearings replaced etc as necessary after examination. If the rings do need replacing then obviously the bores must be honed first and the engine run in properly.

Ok.

We that's what he's said yes. He said it's quite bad initially but does get a bit better as it warms up (or has run a bit, I'm not suggesting the 'warming up' is making the difference). However, even at it's best it's not something he is happy using in a public place.

Ok.

Not off the cuff no but I wouldn't do much outside say a comparison compression test (assuming diesel testers aren't too expensive) without getting the manual for that engine or an idea what to expect on that sort of engine.

When I next see him I'll ask some more specific questions and see if he has or if there is a manual available for it.

Talking to my BIL today who has a diesel transit, he's put some fluid through his van when it starts getting a bit smoky and he says it clears the smoke and is actually noticeable how much better it runs afterwards?

Cheers, T i m

;-)

60 quid on eBay?

Understood and thanks.

I didn't look closely but I think this is a pushrod lump. Assuming the cam is chain / gear driven as we saying it could be miss-timed due to some manufacturing / repair error or that it could have jumped on it's own?

Ok. Could be easy as this engine is sitting out in the open on a trailer (less comfortable in the engine room on a boat). ;-)

Ok.

Understood.

Understood. My first question to him was "valve stem seals?" and I think I remember him saying they had been done. It's not impossible he didn't understand what I was saying but I think he did.

That's what I said (well, the boring bit anyway). He said he has (or believes he has) all the bits needed to do the rings so he should already have top end gaskets etc.

I will get the actual make of the engine off him (he did tell me but it wasn't a name I recognised at the time) and see if they have a UK agent etc.

Cheers, T i m

Transits always benefit from driving them flat out for a bit :-) But blue smoke isn't lack of air/fuel, it's oil.

Or wear on the chain/gears/camshaft. (If it's pushrod then skimming the head won't alter the cam timing)

If it's a random Chinese one then the valve guides are a safe bet & they're not particularly expensive to get fixed at any decent reconditioners.

Very unlikely to have moved on its own. Checking is simply a matter of not taking anything for granted in a diagnosis situation.

Nope, good point, well presented.

A mate tend to get the stuff that the main dealers can't sort. The last one was along the lines you just mentioned, bad alignment marks on the cam pulley. Probably been like that from the factory and ok till you replace the belt and then take notice of the marks (rather than leaving everything locked up and just re-fitting the new belt as-is).

They re-aligned the pulleys several times but to no good effect (no!). Mate puts his dial gauge on there, sets it by the book and grinds / stamps new marks in the right place. ;-)

T i m