Volvo Md22 Smoke and sheen

[Mastermuffin]

Recently swapped out my Perkins m50 for a rebuilt Volvo Md22, I had test started it in my garage for a few minutes and noticed no smoke from the exhaust but discovered someone had messed with the glow plug wiring causing them to stay on. Fixed that issue and test ran it again for a few minutes before putting it in the boat, this time i did notice a bit of smoke on startup but it seemed to go away.

Now that its in the boat it has started smoking and throwing a nasty sheen on the water, especially when cold.

It seems there are quite a few here with experience with these engines so maybe you guys could help!

Ive tried switching to a different fuel source, had the injectors tested, changed the oil and fuel filters, as well as taken it out and ran it between 1600 and 2500 rpm for a few hours now.

Here's a video of the engine running now that its in the boat.

 

[RichardS]

Hmmmm .... that does look like unburned fuel or oil on the water. What did the rebuild actually involve?

Richard

 

[Beneteau381]

Recently swapped out my Perkins m50 for a rebuilt Volvo Md22, I had test started it in my garage for a few minutes and noticed no smoke from the exhaust but discovered someone had messed with the glow plug wiring causing them to stay on. Fixed that issue and test ran it again for a few minutes before putting it in the boat, this time i did notice a bit of smoke on startup but it seemed to go away.

Now that its in the boat it has started smoking and throwing a nasty sheen on the water, especially when cold.

It seems there are quite a few here with experience with these engines so maybe you guys could help!

Ive tried switching to a different fuel source, had the injectors tested, changed the oil and fuel filters, as well as taken it out and ran it between 1600 and 2500 rpm for a few hours now.

Here's a video of the engine running now that its in the boat.

Give us a bell 07967 313792
S

 

[Bobc]

Mine did that too.

I concluded that it was unburned fuel on the water.

I mucked about with everything (injectors, timing, etc, etc. I eventually found that it was due to lack of compression.

These engines have pretty low compresssion to start with, as they were derived from a petrol engine, and any loss of compression means that the fuel cannot be combusted properly.

I would suggest you run a compression test. Depending on where you are, I have a compression tester that you can borrow (I am in Oxfordshire) which works through the glow plug holes (so no need to remove the injectors).

It's an easy test to do, and will quickly tell you if there is either cylinder/piston ring sealing issues or head gasket sealing issues.

 

[Mastermuffin]

Mine did that too.

I concluded that it was unburned fuel on the water.

I mucked about with everything (injectors, timing, etc, etc. I eventually found that it was due to lack of compression.

These engines have pretty low compresssion to start with, as they were derived from a petrol engine, and any loss of compression means that the fuel cannot be combusted properly.

I would suggest you run a compression test. Depending on where you are, I have a compression tester that you can borrow (I am in Oxfordshire) which works through the glow plug holes (so no need to remove the injectors).

It's an easy test to do, and will quickly tell you if there is either cylinder/piston ring sealing issues or head gasket sealing issues.

Would love to borrow it but I'm located near Seattle WA so a bit far ?. Currently having a machine shop make one and then I'll do a leakdown/ compression test.

I bought the engine as "rebuilt". They said all bearing/ rings replaced and head was rebuilt but who really knows. Engine didn't smoke the first time I started it so I'm fairly annoyed that it is now. The main reason I replaced it was because my last engine would burn about a liter of oil every 10 hours and smoke a lot on cold starts, but it never left a sheen.

I have yet to run this one long enough to notice any loss of oil.

Did you end up fixing the issue with the sheen on the water?

 

[Bobc]

Would love to borrow it but I'm located near Seattle WA so a bit far ?. Currently having a machine shop make one and then I'll do a leakdown/ compression test.

I bought the engine as "rebuilt". They said all bearing/ rings replaced and head was rebuilt but who really knows. Engine didn't smoke the first time I started it so I'm fairly annoyed that it is now. The main reason I replaced it was because my last engine would burn about a liter of oil every 10 hours and smoke a lot on cold starts, but it never left a sheen.

I have yet to run this one long enough to notice any loss of oil.

Did you end up fixing the issue with the sheen on the water?

It is always possible that it just needs running in, you never know.

If a compression test does show a problem, whip the head off and measure the bores for ovality (being oval and not round). They may have just replace the rings rather than re-bore with oversized pistons.