Head gasket

[Jim Phillip]

Have a Yanmar 240D that I replaced rings and head gasket on last year. Put about 40 hours? on it and shut it down without problems. Tried to start it when it was cold unsuccessfully. It would just crank and not fire with white smoke. Figured I'd fix it when the weather warmed up. Sat for 4-5 months and I just bled the fuel lines and it started up easily (on a hot day) but I noticed bubbles from the radiator into the overflow bottle which I know is usually a blown head gasket. Should I re-torque the head and start it again to see if it stops bubbling before I remove the head and check it all? Or is that a bad idea? It seemed to be pretty warm when I shut it down after maybe 10 minutes running before I saw the bubbles but the idiot light wasn't on and it was 85deg. out..

 

[bmaverick]

Have a Yanmar 240D that I replaced rings and head gasket on last year. Put about 40 hours? on it and shut it down without problems. Tried to start it when it was cold unsuccessfully. It would just crank and not fire with white smoke. Figured I'd fix it when the weather warmed up. Sat for 4-5 months and I just bled the fuel lines and it started up easily (on a hot day) but I noticed bubbles from the radiator into the overflow bottle which I know is usually a blown head gasket. Should I re-torque the head and start it again to see if it stops bubbling before I remove the head and check it all? Or is that a bad idea? It seemed to be pretty warm when I shut it down after maybe 10 minutes running before I saw the bubbles but the idiot light wasn't on and it was 85deg. out..

When you did the head gasket prior, did you follow the stages and torque sequences before final torque is applied. Then after 10 run time hours, check the torque again, then at 30 hours?

Did you also check for flatness?

Use this as a guide,

Typical for most Yanmar 2-cly diesel engines. BETWEEN each stage, let the time be 30mins between 1st and 2nd. Then 2-hours between 2nd and final.

 

[Jim Phillip]

Yep, I even took it to a head shop and had them check just in case. The install is similar to what you show but it doesn't have cap screws plus the torque is way higher (130ft.lbs.). I took the head off today since it wouldn't start this morning anyway. I really didn't see anything wrong. The mating surfaces were clean and I didn't see any carbonization like I expected. There was some carbon buildup on one of the injectors but most injectors look similar when you remove the head so I'll clean it and put it back together. Since the head is off I put some oil in the cylinders to see if a ring was broken but it been 3 hours and they are still the same. I'm a little baffled.

 

[bmaverick]

BYW, I hope you are running with 10W30 of straight 30W with the Yanmar. We have old bulletins saying not to use 15W40 with these engines as it traps the heat in longer and the problem you are witnessing with the head and bubbles in the coolant would be typical of the heavier oil.

Yanmar for the vintage machines used JIS standards, not SAE in that era. It wasn't until the late 90s Yanmar switched.

I run with Rotella T4 10W30 for diesel. Or use your brand in 10W30 diesel grade.

This meets Yanmar and Deere requirements,