Sump leak after rebuild

[Legend61]

Hello cruisers forum,

Wonder if anyone can give me some advice?

Recently had the engine (yanmar4jh2-te) pulled and rebuilt due to worn rings. And high sump pressure causing excess blow by and a black transom.

When the engine was reinstalled it became apparent that there was an oil leak from the (new) sump gasket. The engineer had put nearly 8 liters of oil in the engine rather than 4.5 as required! Which would not have helped matters!! It was an hour or two before i noticed that, and removed the excess.

Anyway, i am losing around 60ml of oil every 30 to 50 hours now.

For the life of me I cannot face going through the whole get the engine out to fix process, which will involve carpentry, boat on the hard, cranes engineers etc etc.

How serious is this oil leak if I keep a close eye on it and top up as required? We have moved away from the area where the work was done, so cannot return there.

Not an ideal situation after rebuild as i had hoped my engine problems were over! On the brightside my transom is not black anymore and i do not have exces blow by anymore.

Thank you in adavnce.

[jimbunyard]

Can you see where the gasket is leaking? Seems a little odd that running the engine with 3.5 liters extra would cause leaks in the pan gasket, or even seals, but stranger things have happened.

In 'Merikan' units 60 ml/30-50 hrs works out to about 1 oz every 2000 miles, so I don't think that's very serious...would be curious if it wasn't normal consumption whilst the rings were seating; definitely not a cause to pull the engine.

Keep an eye on it and fix it if it gets worse

[oldtom]

Ledgend61 Can you see oil leaking between sump & block clean down test run UNDER LOAD at full R.P.M good tie up too some thing thats not going to move run till at full op temp 15/25min if it leaking go cleanup the mess if not run it in undera load.

[Sulaire]

Hi

Thank you for the responses.

I can see oil “sweating “ out between pan and block in a couple of places. This oil first gathers on the sump bolts, then runs down under the pan to drip in the engine tray. I have had a good look higher up on the engine but can see no sign of any oil, so assume it is the sump gasket, but I could be wrong.

I am at around 120 hours after rebuild, and have babied the engine so far at around max 2500 revs, no more than 1500revs for first 20 hours after rebuild on the engineers recommendation, and oil changes after 10, 20 and 50 hours, maybe it is time to let her go! And see what happens....?

[Legend61]

Sorry, last post was using my wife’s account!

Same boat same problem!

Legend61

[jimbunyard]

Believe it's time...

In my opinion it's more important to keep varying the rpms than to avoid any specific limit, except for the first few hours. Stay away from sustained WOT obviously, but brief excursions there are beneficial. At 120 hrs, you should be good to go, but still limit WOT use as common sense dictates.

If you have room, try tightening (not overtightening!) the pan bolts with a 1/4" drive ratchet and extension, following the manufacturers sequence if you can get it and you have access, if sequence is not available, from the center out, sequentially side to side.

[Legend61]

Thanks jimbunyard, i agree about time to try more revs.

I did tighten up some bolts where the leaks looked to be, but still no luck.

[hellosailor]

If oil is weeping past a number of bolts, that suggests the greasemonkeys did not properly clean off the old gasket, or they improperly used a new material (form-a-gasket perhaps) or they bent up the edges of the oil pan so it is no longer a flat-on-flat joint. I don't really know any way that can be repaired without dropping the pan in order to thoroughly clean out the gasket and reseal the joint, sometimes with a better sealant/gasket, sometimes with a new pan.

If I really had to kludge it...I'd steam clean the joint and the bolts, and then apply a coating of epoxy or similar to literally encapsulate the joint and seal it. Maybe not an elegant solution, and a nuisance next time you drop the pan, but seeing as you're not going to be doing that real soon (knock wood)....Well, it should work. Multiple coats, throughly cured before starting the engine.

Maybe some of the roofing materials FlexSeal or roofing mastic) would also do it, but I've no idea how those would take to prolonged heat and oil the way epoxy can.

[captlloyd]

Originally Posted by hellosailor

If oil is weeping past a number of bolts, that suggests the greasemonkeys did not properly clean off the old gasket, or they improperly used a new material (form-a-gasket perhaps) or they bent up the edges of the oil pan so it is no longer a flat-on-flat joint. I don't really know any way that can be repaired without dropping the pan in order to thoroughly clean out the gasket and reseal the joint, sometimes with a better sealant/gasket, sometimes with a new pan.

If I really had to kludge it...I'd steam clean the joint and the bolts, and then apply a coating of epoxy or similar to literally encapsulate the joint and seal it. Maybe not an elegant solution, and a nuisance next time you drop the pan, but seeing as you're not going to be doing that real soon (knock wood)....Well, it should work. Multiple coats, throughly cured before starting the engine.

Maybe some of the roofing materials FlexSeal or roofing mastic) would also do it, but I've no idea how those would take to prolonged heat and oil the way epoxy can.

Not a bad idea, I would go with the form- a- gasket compound. If the oil is just seeping it might do the trick. And yes, the engine to pan joint must be very clean for this to work. Try a degreaser and then solvent. Good luck.

[billknny]

Originally Posted by hellosailor

If oil is weeping past a number of bolts, that suggests the greasemonkeys did not properly clean off the old gasket, or they improperly used a new material (form-a-gasket perhaps) or they bent up the edges of the oil pan so it is no longer a flat-on-flat joint. I don't really know any way that can be repaired without dropping the pan in order to thoroughly clean out the gasket and reseal the joint, sometimes with a better sealant/gasket, sometimes with a new pan.

If I really had to kludge it...I'd steam clean the joint and the bolts, and then apply a coating of epoxy or similar to literally encapsulate the joint and seal it. Maybe not an elegant solution, and a nuisance next time you drop the pan, but seeing as you're not going to be doing that real soon (knock wood)....Well, it should work. Multiple coats, throughly cured before starting the engine.

Maybe some of the roofing materials FlexSeal or roofing mastic) would also do it, but I've no idea how those would take to prolonged heat and oil the way epoxy can.

Most cured epoxies soften irreversibly when exposed to temperatures over 230F (110C). That would seem to make them a poor choice for trying to seal an engine oilpan. I think the chances of it actually working for more than the very short term are really really slim. The temperature cycling and differential expansion will cause any bond between the epoxy, the oil pant and the block to fail very quickly

If I saw this kind of "repair" on any boat I was considering buying, I'd run away, screaming. I know that is not the OP's concern right now... but someday it will be.

[captlloyd]

Originally Posted by billknny

Most cured epoxies soften irreversibly when exposed to temperatures over 230F (110C). That would seem to make them a poor choice for trying to seal an engine oilpan. I think the chances of it actually working for more than the very short term are really really slim. The temperature cycling and differential expansion will cause any bond between the epoxy, the oil pant and the block to fail very quickly

If I saw this kind of "repair" on any boat I was considering buying, I'd run away, screaming. I know that is not the OP's concern right now... but someday it will be.

At the pan area of an engine block the temperatures are not all that high, that’s why you can use form-a- gasket to begin with. I also don’t think you can judge a boats condition by a mistake an engine mechanic may have made. By the way, the OP owns the boat, not buying it, kind of an insensitive remark.

[hellosailor]

I would never try to use form-a-gasket OVER a leak to seal it. When it first came out Loctite had big trouble trying to sell it. They gave away tons of samples, the mechanics said it was crap. Turns out, the mechanics were not using it or applying it according to the instructions. Why say only to use it between two clean surfaces that will be bolted together under pressure.

They got back market share after they ran some Indy cars that were just "glued together" with all the correct products in all the correct places. But slapping this over a leak? No way, just like RTV it would only blow off. It is NOT a high bond strength adhesive like epoxy.

[Wotname]

While it might be obvious to most, it should be mentioned that if doing any "goop on the outside of the joint" style of repair, the pan should be empty of oil and the external joint surfaces be super clean. I might try some high temp silicone sealant.

It would be a great help to first know exactly where the joint had failed and only apply sealant around that area.

[captlloyd]

Originally Posted by hellosailor

I would never try to use form-a-gasket OVER a leak to seal it. When it first came out Loctite had big trouble trying to sell it. They gave away tons of samples, the mechanics said it was crap. Turns out, the mechanics were not using it or applying it according to the instructions. Why say only to use it between two clean surfaces that will be bolted together under pressure.

They got back market share after they ran some Indy cars that were just "glued together" with all the correct products in all the correct places. But slapping this over a leak? No way, just like RTV it would only blow off. It is NOT a high bond strength adhesive like epoxy.

The oil in an engines pan is under very low pressure, if any pressure at all. It does splash around a bit, hence causing seepage if a poor seal. The sealant might not totally stop the seepage, but could make the situation bearable.

[Mithril Bham]

Bite the bullet. Do it right and have company who caused the problem fix it. Halfway measures could work but are usually a bad idea. I realize you don't want to pull the engine again and don't blame you.