Dipstick

[Jasper]

Hi All,
Some advice please.
My 53 Conv has 12V71N's with a few hundred hours SMOH. They run well, although a bit smokey.
Question: Port engine keeps popping the dipstick a few inches out of the engine after a a good run. It leaves oil splashes over the ER as you can imagine. At first I thought I had forgotten to replace the dipstick properly, but last time made sure it was properly pushed in. Oil pressure/levels at normal full etc.
Thanks
George

 

[rsmith]

Hi All,
Some advice please.
My 53 Conv has 12V71N's with a few hundred hours SMOH. They run well, although a bit smokey.
Question: Port engine keeps popping the dipstick a few inches out of the engine after a a good run. It leaves oil splashes over the ER as you can imagine. At first I thought I had forgotten to replace the dipstick properly, but last time made sure it was properly pushed in. Oil pressure/levels at normal full etc.
Thanks
George

Check the breather tube that goes up to the intakes is clear. Pull the stick and put your finger over the tube to see if you have blow by pressurising the crank case.

 

[Jasper]

Check the breather tube that goes up to the intakes is clear. Pull the stick and put your finger over the tube to see if you have blow by pressurising the crank case.

Thanks rsmith. Will try to find this by using the manual. I am not very mechanically minded!
Can this cause a major problem?

 

[rsmith]

I've never had a dipstick blow out. But I would do some investigation before I jumped to any conclusions. Do you have filters on the airbox drains and are they piped into the crankcase vent? If so and the vent is pluged that could pressurise the case. The worst case senario would be stuck or broken rings.

 

[Jasper]

I've never had a dipstick blow out. But I would do some investigation before I jumped to any conclusions. Do you have filters on the airbox drains and are they piped into the crankcase vent? If so and the vent is pluged that could pressurise the case. The worst case senario would be stuck or broken rings.

I think I best call someone who knows more than me. I don't know what I am looking for!
I'll make some calls and try find someone I trust. The best guy for the job lives 4 hours away so wish me luck! The local MTU DD guys are VERY EXPENSIVE, I think they haven't yet realised there is a recession.
Thanks again.

 

[captbuddy]

rsmith is right. I had the same problem with my 453N and a friend of mine told me to check the tube. Mine goes in an old gallong oil jug that is cut in half. I had it sticking into the diaper I had in the bottom. When I make sure it is above the diaper, no more dip stick backing out.
captbuddy

 

[DLCameron2]

Check the airbox drainback check valve.

DC

 

[rsmith]

Check the airbox drainback check valve.

DC

I think the checkvalves are only on TI's he has N's. I have my vents going into milkjugs also. I was always going to pipe the drains into the breather tubes untill I Cleaned out the airboxes when I RB the engines and saw the amount of sand and mud I dug out of all the nooks and crannies of the boxes.I didnt think sending any of that thru the engines for a second time was a good idea.

 

[Jasper]

I've never had a dipstick blow out. But I would do some investigation before I jumped to any conclusions. Do you have filters on the airbox drains and are they piped into the crankcase vent? If so and the vent is pluged that could pressurise the case. The worst case senario would be stuck or broken rings.

As always;
Thanks all!
I have spent most the day in the engine room and found what I think you are advising. I found the pipes from the crankcase (two of, one from each side of each engine) and they were fed into a large PVC canister which HAD been full of steel wool pads. I think the problem was caused by me! Surprise huh!
I have cleaned these out after my long trip (300nm) as they had quite a lot of oil in them and cleaned some of the steel wool and replaced the balance with rags.
So: I believe with my last few trips, where I gave the engines a full throttle burst etc. I blocked these breather pipes on the Port engine with too many rags.
Today I again cleaned them out, replaced all the rags with steel wool and have made sure there is plenty of space for the breathers to vent.
Let’s hope I have done no major damage, or blown gaskets or similar. There is good air venting from the pipe when I run in neutral, unfortunately cannot get out to the deep water to give it a test today. Have to wait for High Tide to get out from where she is moored.
Thanks rsmith and all.
Regards.
G

 

[rsmith]

I wouldnt worry about it 12/n's are pretty bullet proof.
I usualy bring the engines up to full throttle to get the boat on the plane quicker run them at 2300 for a minute then bring them back to 2100. IMO its easier on the engines to get the boat over the hump and cranking along.

 

[Jasper]

I wouldnt worry about it 12/n's are pretty bullet proof.
I usualy bring the engines up to full throttle to get the boat on the plane quicker run them at 2300 for a minute then bring them back to 2100. IMO its easier on the engines to get the boat over the hump and cranking along.

Well I will find out this weekend, we are going whale watching a few mikes offshore.
The engines are still using a lot of oil from what I am used to.
Only 208 hours on each so far. Very smokey when I take her to 2300 then they settle back and at 2000 are okay, but still show some smoke.

 

[rsmith]

This is the oil I've used in my 12's for 35 years and near 10,000 hours. I have friends in the mining industry and trucking industries that swear by it. I buy it by the 55 gal drum.

http://www.le-international.com/productdisplay.aspx?id=54

 

[Jasper]

This is the oil I've used in my 12's for 35 years and near 10,000 hours. I have friends in the mining industry and trucking industries that swear by it. I buy it by the 55 gal drum.

http://www.le-international.com/productdisplay.aspx?id=54

Hi rsmith,
I assume from the product sheet that you are using the #8440 which is 40W?
I have found 40W from the MTU DD dealer here. For the trip from the cargo ship to home I could only find high quality multigrade 30W/50W until I got halfway and found a trawler supplier who had 40W.

 

[Canuck Dennis]

Routing the airbox drains to the crankcase breather outlet at the air intakes is not recommended by DD, they have concerns re, potential run away..

 

[rsmith]

Hi rsmith,
I assume from the product sheet that you are using the #8440 which is 40W?
I have found 40W from the MTU DD dealer here. For the trip from the cargo ship to home I could only find high quality multigrade 30W/50W until I got halfway and found a trawler supplier who had 40W.

Yes the 8440 is what I use.

 

[REBrueckner]

"My 53 Conv has 12V71N's with a few hundred hours SMOH. They run well, although a bit smokey."

After "overhaul" smoky is not what you should expect....
that covers a wide range of possible work.....What did the overhaul entail?? Maybe the injectors need to be checked....??

 

[Jasper]

"My 53 Conv has 12V71N's with a few hundred hours SMOH. They run well, although a bit smokey."

After "overhaul" smoky is not what you should expect....
that covers a wide range of possible work.....What did the overhaul entail?? Maybe the injectors need to be checked....??

Well that is news to me!
I was told that until the "new" OH engines settle in, they use a bit more oil and smoke a bit more. They Smoke only when I rev them up and then settle down ok, although even at cruise I still see some smoke, more than I am used to after having boats with Cummins and MAN engines.
As for the OH, I have the invoice from Piedmont Engineering for close to $40,000 NOT including taking the old engines out or installing the Overhauled ones.
The engine surveyor gave me a TOP report and we even checked the pistons and found them to be new, DD parts with all the right markings etc.
Your thoughts?
Thanks and Cheers

 

[rsmith]

If your talking about the smoke haze behind the boat that you need to look at the horizion to see, thats just the way it is with the garbage fuel we get today.

 

[REBrueckner]

what rsmith said...plus "They Smoke only when I rev them up and then settle down .." If that's a quick increase in throttle and RPM under load it's probably normal.

I don't personally think that's ever a good idea especially if the engine is not warmed up; on the other hand the commercial lobster boat owners sure don't baby their engines.

 

[34Hatt]

If your talking about the smoke haze behind the boat that you need to look at the horizion to see, thats just the way it is with the garbage fuel we get today.

Really because I have no haze at all ZERO!


But I do agree with the fuel has gone down hill BIG time. But I have no haze at all so can't be the fuel.