Volvo Penta MD20*0 - potential problems

[SV Kittiwake]

Our next boat has a Volvo MD 2040. So far we've escaped the murky world of marine diesel engines by having a petrol outboard powered boat, which has been fantastic.

Now I'm trying to get my head around looking after the diesel. The generic things seem easy to learn from Nigel Calder and Don Casey books and articles. But I wanted to check with current owners of these engines what stuff to look out for which is specific to this range. So far, from digging around I've got:

Exhaust elbow seems like a shitty cast iron job which blocks and rusts, so I'm planning on replacing it with a stainless one from parts4engines. Then regular flushing should keep it blockage free?

The relay box seems poorly designed and the connections wriggle loose causing starting problems, so people seem to stuff the top of the box with a bit of plastic or something to hold the connections down - is there a better solution to this?

I've also read of some people having problems with glow plugs (but this isn't MD2040 specific) - do people replace their glow plugs at a set interval, or just wait until something goes wrong with them? Is it worth taking them out and copper greasing the threads to stop them getting stuck when they do need to be removed?

What other preventative maintenance do people do which is specific to this engine?

 

[tillergirl]

I have a 2030 which I bought in 1994. A brilliant engine, quiet and smooth. Exhaust elbow - It's a service item but hardly an annual issue - replaced in year 17. Glow plugs - replaced in year 15. Relay box - sorry no problem at all. Other problems? Serviced the water pump in year 19. Serviced the injectors in year 20 (£120). Annual service of course which is simple and less frequent such as tappets is also easy. Oh, the gearbox filler cap needs a new 'O' ring each time. Been pretty boring really.

 

[Quandary]

If the OPs experience is based on reading all the doom in this forum then the pessimism is not surprising, like tillergirl my 20 series is past its 20th birthday and still going fine on its first 'shitty cast iron' elbow, the electrics are fine and the only major thing has been sail drive diaphrams, which when they are replaced look good for another 20 years.
Sticking my neck out here, wonder what is about to go? Meanwhile I will find out the correct spelling of diaphragm.

 

[SV Kittiwake]

Thanks for the info Tillergirl, that's really helpful. I'll order some gear box cap o-rings. Good to hear you're not having many problems - boring is good when it comes to engines!

 

[SV Kittiwake]

If the OPs experience is based on reading all the doom in this forum then the pessimism is not surprising, like tillergirl my 20 series is past its 20th birthday and still going fine on its first 'shitty cast iron' elbow, the electrics are fine and the only major thing has been sail drive diaphrams, which when they are replaced look good for another 20 years.
Sticking my neck out here, wonder what is about to go? Meanwhile I will find out the correct spelling of diaphragm.

I'm not pessimistic, I just want to preempt any problems. Given that it's a green Perkins I hope it'll be good if we'll looked after. I'm just nervous about costly parts so if there's maintenance I can do to prevent repairs then I'm keen to do it.

 

[Tranona]

Just to add to the praise above. My last boat had a 2030 that did 3500 trouble free hours mostly used as a charter boat. The exhaust elbow issue is common to most small diesels and can be avoided by running the engine hard. what they don't like is running lightly loaded and running for short periods then shut down without getting fully hot. In other words typical "weekend" yottie usage.

Appreciate difficult to follow this advice all the time and while fitting an SS elbow might lead to a longer life before corroding, it does not change the propensity to get blocked up!

Change the oil and filter frequently - maximum 150 hours between changes and coolant no more than 3 years. No need to touch glow plugs or injectors unless you experience starting problems.

I can understand your nervousness, but in 5 year's time you will wonder what all the fuss is about!

 

[duncan99210]

Our 2030 has 4500+ hours on it. We’ve added about 2500 in the nine years we’ve owned it. During that time I’ve had the injectors serviced and injection pump rebuilt (after the injection pump stopped working), a new exhaust elbow at 4000 hours or so and I rebuilt the raw water pump this year using a service kit.
The relay box contacts for the starter and glow plug relays may need nipping up if you ever get a problem. Otherwise, regular servicing sees it all fine. Good reliable engine: just about any problem (bar the injector pump) was simple to resolve and not cripplingly expensive. Parts are readily available, often as after market parts rather than Volvo branded stuff.