Marine surveyor Ben-Sutcliffe Davies finds corrosion in the Volvo saildrive engine onboard PBO Project Boat Maximus

Checking the diesel engine after a long lay-up is an essential task before launching any boat, says marine surveyor Ben Sutcliffe-Davies.

“The last thing you want to be doing is putting the boat straight in the water,” warns Ben. “You need to be really religious with fuel management. Empty the fuel tank, flush it, change the fuel lines, fuel filters, turn it over and see the engine running ashore with a water feed, rather than just pop it in the water and hope.”

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In this video, Ben is surveying the engine of the new PBO Project Boat, Maximus. The engine is an indirectly cooled 3-cylinder Volvo 2020D. It’s rated at c19hp and uses a Perkins engine base. Unfortunately Ben’s unable to start it as the cranking battery was fully discharged.

Rotten framing

The good news is there are no significant oil leaks and the engine beds are in good condition. However, Ben spots some noticeable surface corrosion caused from water ingress through the companionway, and the framing is rotten.

I think you can safely say it’s rotten when you push your finger through it,” he says! “Obviously we’re not connected to shore power, but it’s not very clever when you’ve got water running over the top of shore power electrics like here, and really again it should be flexible cable rather than solid copper wiring.”  

“The biggest problem you’ve got here is the lack of use. It’s been stood here for some time and you can see how much corrosion there is on things such as the flywheel, on the pulley wheel here,” he adds. 

Advice on Antifreeze

Ben points out the radiator cap of  the internally cooled engine. The water coolant on this particular engine comes through a hose from the saildrive.

“It’s quite a dark green coolant water in there so the antifreeze is fairly tidy,” he says. “It’s really important to change them every two or three years because the inhibitors we’re now using with environmentally friendly stuff will now corrode and become an aggressor.”

Engine seacock

The engine seacock is almost impossible to reach, though the strainer is in a reasonably nice place to look at. 

The caps are notorious for corroding off, advises Ben, and the manifolds are also quite common for corrosion.

“That piece of exhaust hose is absolutely impossible to see and you’ve got a little plastic silencer there with a couple of clamps on,” he points out. “None of that looks secure. It’s just waving around in the wind.” 

Perkins base engine

Ben shows us the Volvo Penta serial number underneath the fuel pump. These always start with 510 but it’s this last set of digits you need.

“One of the beautiful things about Volvo is they’ve used a Perkins base engine,” says Ben. “It’s always worth getting that information because anywhere in the world if you need spares for Perkins it’s the same engine.” 

Engine mounts

“Engine mounts should be changed at the same time as when you do your donut on your saildrive,” advises Ben. “If you haven’t got a saildrive and you have a normal shaft look at doing these every 10 years.”

He points out the corrosion on the support bracket where there’s been quite a bit of thinning.

“Always look for the fastenings on the bolts. I always find that a few bolts have come loose. It’s when you can turn them with your hand that you have a problem.”

Although Ben isn’t able to start the engine with the battery he turns it by hand.

“You can hear that turning can’t you?” he asks. “Well at least you know after two and a half years it hasn’t seized, which is a good sign!” 

Watch the videos and read more

A few months later, we asked our engine expert Stu Davies and wife Laura to come down to Maximus. Here are the videos of them servicing the Volvo MD2020.

Or, alternatively, you can read the full article on servicing a Volvo MD2020 saildrive engine here.

Thanks to our Project Boat Supporters

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