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Volvo D41 smoke from breather and air filter. Help

Armeria

New member
Hi Everyone,

I am a new member and not a mechanic. I have used a local mechanic on my boat (1996 Commander 30) for 7 years but he is a mobile mechanic and cannot help me with this issue.

The engine started to smoke when revving to turbo speed so I shut it down and now it smokes through the breather tube and air filter as well as running lumpy, maybe 5 cylinders.

I am told the engine needs to be pulled and rebuilt, probably a ring and/or valve.

Is there any value in doing a compression test?

Can anyone recommend where I should take it for service that won't fleece me and does anyone have any idea what a rings and valves rebuild might cost?
I am in Cowichan Bay.

Thank you for any input you may have to help me make a decision on this.
 
Any noise you can describe? Thinking a simple stuck or broken valve component maybe. I had a adjustment stud break once and
it was a lucky cheap simple fix but it came with alot of expensive sounding noise as well. Might suggest you take covers off and
examine valve train operation and maybe location of where smoke is entering the covers. By air filter ... do you mean intake or a
oil breather canister filter?
 
Any noise you can describe? Thinking a simple stuck or broken valve component maybe. I had a adjustment stud break once and
it was a lucky cheap simple fix but it came with alot of expensive sounding noise as well. Might suggest you take covers off and
examine valve train operation and maybe location of where smoke is entering the covers. By air filter ... do you mean intake or a
oil breather canister filter?

Thank you for responding so quickly! Yes, there was an initial noise which sounded like a 'Whirrr" and the lost rpms off turbo speed. After I shut it down, I restarted and ran at 1500 rpms and all sounded well. I tried again another day, all was well until I wound her up to turbo speed and then a clunk and a slow down and smoke coming out of the air filter canister and breather tube and also oil around the filler cap. I started it again in the marina and smoke was coming out of both places again and she was running lumpy. Does that help? :-{
 
Just guessing now... hopefully others will chime in here...
I would take the air cleaner cover off and with engine off check the turbo for
a frozen or wobbly fan blade. If the turbo let go maybe somehow exhaust is
bypassing the turbo seals and pressurizing the crankcase thru the drain.
 
Thank you, that sounds like a good option to start before pulling the motor, I'll see if I can do that or find someone who can. Great help!
 
A compression check is a good way to eliminate valves and rings from the problem. It could be a spun bearing in the turbo. It's common in older engines or engines with poor maintenance to have the oil passage to the turbo become restricted with soot buildup. When that happens the turbo bearing doesn't get enough oil for lube and cooling. The exhaust gasses turning one side of the turbo are above 600°F. On turbo engines I have owned, mostly big HD engines, I usually change the turbo bearings and seals at about 1/2 turbo life. It's good, cheap insurance. If you did spin a bearing, either the housing or shaft could be damaged and need close inspection.
If the problem is the turbo bearing, the seals are usually wrecked and the exhaust gases will push thru to the intake side, heating and maybe burning the normal lube oil. Also at speed the bearing drags, so the usual amount of boost air is less at turbo speed and you have less power. Running with a bad bearing could damage the turbo beyond economical repair. Just run enough for dockside trouble shooting.
 
Thank you Lepke,
This is sounding more reasonable than pulling the engine, I will get someone
to do a compression test first. Is it the same as a gas engine process or is
it more tricky?
 
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