Volvo AD31 oil problem

[Viscount]

I have 2 x AD31s. 1 is fine but the other is blowing oil out the crankcase breather relief valve at the rate of a pint in 30 minutes under hard running. Anyone know what to do about this?

 

[rcgt78]

Re: Volvo AD31 oil problem

Hi!<br /><br />I believe that this will happen if the crankcase ventilation filter is too dirty. <br /><br />But, maybe you have already checked and replaced the filters. <br /><br />I have one AD31 130 Hp in my boat!<br /><br />Robbi

 

[Don S]

Re: Volvo AD31 oil problem

What model AD31? And what is a crankcase breather relief valve. Never heard of one.

 

[LubeDude]

Re: Volvo AD31 oil problem

Not a good sign. You have excesive blow by caused by something. Bad (cracked ring), hole in piston, etc. Do a compresion test on that engine.

 

[rabidfish]

Re: Volvo AD31 oil problem

You may need a cylinder leakdown test.<br />The results of that will tell us what to do.<br /><br />Also, the valve has a spring, make sure the spring seats the valve, or that the valve isn't crooked in the sleeve. Also, the filter does need to flow freely, if you haven't changed it, you should.

 

[rabidfish]

Re: Volvo AD31 oil problem

Also, for Don: on the side of the engine there are inspection covers (much like on a gas 3.0L)<br />on the aft cover, there is a filter, and a "check valve" a single spring, loading a disc onto a seat.<br /><br />Volvo uses it on several diesel models

 

[Don S]

Re: Volvo AD31 oil problem

Interesting.....I have rebuilt a 41, 2, 42's and 2, 43's in the past couple of years, never even seen but one of the 31's, but it was a newer one (P-A) and did not have that filter. Thanks for the info.

 

[rabidfish]

Re: Volvo AD31 oil problem

No problem.<br />I think you would be nearer to see it on an auxillary (sailboat drive) than on the inboard or sterndrives. I think(not seen it myself) some generators use it. ( I don't work on gens... just heard it at a seminar someplace )<br /><br />It's not on any of the new models (that I have seen)