Sump leak after rebuild

[jimbunyard]

Might be a chance to gain some experience--and confidence.

First things first.

Scrape off some of the extruded material and see if you can discern whether or not there is a gasket. You won't make matters worse by doing this.

If there is, you may be able to stop the leak without removing the pan.

Since you have a cast pan you can eliminate the possibility that the seepage is caused by 'dimple distortion' of sheet metal.

That leaves poor cleaning, pre-existing pan distortion, induced pan distortion, under or over or out of sequence tightening, or, possibly more remotely, an individual throughbolt-into-the-crankcase leaking.

If there is no gasket, it is very likely that you'll have to remove the pan to repair this permanently.

But neither instance is a reason not to try the simplest things first.

As previously suggested, pull the bolts that have oil drops on them, clean them of oil, goop them up with gray permatex (for best results an even layer pressed into all the threads works best), and screw them back in, tightening to about 10 ft/lbs; i.e. not much at all. Wait ten hours, and then see if the problem's solved.

If it were me I'd combine the above attempt with the 'loosen all and re-torque' method suggested previously. In more detail, loosen all the pan bolts three turns, then, following the manufacturers sequence, tighten all bolts in three steps; initially just till the bolt bottoms out, then following the sequence, to half rated torque, then finally, again, following the sequence, to full specified torque, if there is a gasket maybe 5 or so lbs. over.

It maybe a little difficult to do this with a torque wrench, even a small one, as the clearances are tight and the torque is so low; for those bolts it's likely to be 15 lbs or less. With practice, and a standard 1/4" drive ratchet, satisfactory results can be achieved just by 'feel'.

The reason for this sequential tightening is that, especially with a cast pan, you can actually 'tighten in' distortion, which can lead to uneven clamping of the joint even though the bolts are at spec. Which can lead to leaks of the type you're experiencing.

If none of this works, as before, unfortunately the pan will have to come off. Not to misrepresent the difficulty, but from your pictures it seems you have a bit more room than is often the case, so the job at least looks doable. If you can remove the pan completely from under the engine to work on it on the bench, half the job is simplified. If the gasket comes off with the pan, 99% of the job's simplified (I'll leave to your imagination what the chances of that are).

Of course if it comes down to that, the same sequence and torque specs must be followed when replacing the pan...

[Legend61]

Thank you everyone for taking the time to help me out, I really appreciate all your inputs, I am looking for ideas and thats what you are giving me.

The more i look at it the more I am considering doing it myself as there MIGHT be room to drop the pan under the engine.

I do have the service manual for the engine, but there is no mention of torque values for the pan bolts or sequence, only torques for block bolts etc. So i will need to hunt more for that info.

Not going to rush into this, have found that pondering the situation for a while usually brings out hidden detail and work arounds.

I had assumed the oil on the bolt heads was weeping out the gasket above the bolts and pooling on them, had not considered that the bolts themselves could be the source of the leaks. Hmmm.

Very reluctant to even consider going back to original engineer for obvious reasons, even if it would be covered under any guarantee, surely this is basic stuff for a mechanic, makes me wonder about the rest of the rebuild!

Anyway still information gathering, so keep any ideas coming.

One guy on a baba 30 next to me during the refit, decided he had enough of engine problems and took his out, sold it and the prop and sealed up the shaft hole, then bought a long sweep oar... sounds a solution!![emoji75]

[jimbunyard]

I've never been a fan of Yanmar and this illustrates just another reason.

Obviously the pan is designed to increase rigidity in lower portion of the block, and yet there is no mention of a sequence in attaching the pan to the block. I wonder if there is at the factory, or if it's been 'engineered out' of the assembly line?

http://www.endeavourowners.com/dscsn...e%20Manual.pdf

Anyway, there is a torque table of sorts, that was added, apparently as an afterthought, according to the manual itself, in April of 2001



If you decide to attempt a repair, since your bolts have the '7' and I assume are 8mm, the proper torque would be 25.5 Nm, which is about 19.75 ft lbs. Since the factory doesn't appear to attach any importance too it, I'd go with a three step, center out, alternate side to side schedule, much like tightening a head, and hope for the best...

[darylat8750]

Originally Posted by jimbunyard

Might be a chance to gain some experience--and confidence.

First things first.

Scrape off some of the extruded material and see if you can discern whether or not there is a gasket. You won't make matters worse by doing this.

If there is, you may be able to stop the leak without removing the pan.

Since you have a cast pan you can eliminate the possibility that the seepage is caused by 'dimple distortion' of sheet metal.

That leaves poor cleaning, pre-existing pan distortion, induced pan distortion, under or over or out of sequence tightening, or, possibly more remotely, an individual throughbolt-into-the-crankcase leaking.

If there is no gasket, it is very likely that you'll have to remove the pan to repair this permanently.

But neither instance is a reason not to try the simplest things first.

As previously suggested, pull the bolts that have oil drops on them, clean them of oil, goop them up with gray permatex (for best results an even layer pressed into all the threads works best), and screw them back in, tightening to about 10 ft/lbs; i.e. not much at all. Wait ten hours, and then see if the problem's solved.

If it were me I'd combine the above attempt with the 'loosen all and re-torque' method suggested previously. In more detail, loosen all the pan bolts three turns, then, following the manufacturers sequence, tighten all bolts in three steps; initially just till the bolt bottoms out, then following the sequence, to half rated torque, then finally, again, following the sequence, to full specified torque, if there is a gasket maybe 5 or so lbs. over.

It maybe a little difficult to do this with a torque wrench, even a small one, as the clearances are tight and the torque is so low; for those bolts it's likely to be 15 lbs or less. With practice, and a standard 1/4" drive ratchet, satisfactory results can be achieved just by 'feel'.

The reason for this sequential tightening is that, especially with a cast pan, you can actually 'tighten in' distortion, which can lead to uneven clamping of the joint even though the bolts are at spec. Which can lead to leaks of the type you're experiencing.

If none of this works, as before, unfortunately the pan will have to come off. Not to misrepresent the difficulty, but from your pictures it seems you have a bit more room than is often the case, so the job at least looks doable. If you can remove the pan completely from under the engine to work on it on the bench, half the job is simplified. If the gasket comes off with the pan, 99% of the job's simplified (I'll leave to your imagination what the chances of that are).

Of course if it comes down to that, the same sequence and torque specs must be followed when replacing the pan...

Best advice. Also it may be possible to raise the engine a bit to get at the pan bolts without turning it into a huge job.

[Legend61]

Wow, thanks very much for that info, i could not find it. My engine is 1992 vintage, as is the service manual, so that explains missing info!

Still poking about in the bilges with a torch and mirror on a stick!

[hellosailor]

And once again...or twice.

I didn't suggest "slathering" epoxy on it. You sound like one of the greasemonkeys that told Loctite that Form-A-Gasket didn't work. They just slathered it on, ignoring the instructions. That's not the same as proper application.

And second, once again, the OP has made it rather clear that they CANNOT simply remove the pan and install a new gasket, unless they get a crane and remove the entire engine from the boat. A very expensive and inconvenient job apparently. Yes, there are many marine installations where there simply is no clearance to drop the engine pan without raising the engine. While you can often kludge around the need for a crane by other means, you still can't "simply" drop an engine pan from many of them. You seem to keep ignoring the OP's stated want to not hire a crane and do major mechanical work associated with an engine removal.

[Terra Nova]

Originally Posted by hellosailor

...they CANNOT simply remove the pan and install a new gasket, unless they get a crane and remove the entire engine from the boat...

This is pure baloney.

[chris95040]

Originally Posted by hellosailor

That's not the same as proper application.

Hehehe. A "proper application" of epoxy to the exterior of a leaking gasket.

You crack me up dude.

[jimbunyard]

From the posted pictures I would say with 99% certainty that the pan gasket can be changed with the engine in place; for reference I've personally changed the sump gasket (that is a gasket on a plate on the bottom of the oil pan) on a 6-71TI entirely by feel, one couldn't even see the bolts, or the plate...

There are many difficulties associated with trying to stop the leak from outside; we're not sure where the leak is, even if we did, to stop it would require sealing the entire pan/block joint because the oil will eventually just work its' way around to wherever the sealant stops or fails to adhere. If one of the pan bolts is leaking that is another potential source, though it could be removed and sealed separately, as has been previously suggested. Finding a material to fulfill the requirements for the long haul is another issue; I know of none that would stand up to the temperature and vibration in this application, at least for very long.

The engine has essentially just been rebuilt, if the owner can reasonably expect another 5-7000 hours it seems to me that it would be worth his while to repair it, dare I say?, the right way now. I have nothing against creative solutions, it just doesn't seem that a surface sealant is the right one in this case.


As an aside, I'm not familiar with this engine, but I think it would be prudent to check that the breathing system is in order. Sometimes they can be a bit arcane, and if not routed or plumbed correctly, pressure can build in the crankcase, which can lead to sealing problems. Won't hurt to double check...especially with a fresh rebuild.

[hellosailor]

No, not applying epoxy to the exterior of a gasket. Applying epoxy to bridge two pieces of metal, which from the description are tightly affixed to each other but still not *sealed* by the gasket. It is very simple for the edge of the oil pan to have been dented during handling, which would mean it is no longer a flat surface, and no flat gasket--new or existing--would then seal the two, until the pan had been flattened out sufficiently. Sealing over what is effectively now a "crack" in one rigid assembly, is a job epoxy works very nicely for. In fact, JBWeld has long been used to seal cracks in engine blocks and heads, per their own instructions.
Criticize all you will, but so far you guys have offered the OP no help at all beyond "Spend lots of time and money".
What I suggested may not be pretty, but it has been known to work.

Jim, you are totally right about "doing it right" and that working blind in tight spaces may be all that's required. OTOH, if the OP tells me that it can't be done without removing the engine...I'll take him at his word. Especially if someone dented the edge of the oil pan, and somehow that has to be banged out flat. Or, if they scratched the bottom of the block (mechanics can be SO creative) deeply enough to that "just" a gasket scraping won't be enough to seal that.

I once had to replace a boat's thermostat with a rock. Yes, a rock. A carefully chosen rock. My friend the owner was terribly upset until the third crew, an engineer, pointed out that it was, after all, an "insoluble diverter valve" of a sort and so should work perfectly well within a given temperature range.

And the boat ran just fine, with a rock instead of a thermostat, until a new one could arrive. (We didn't always have overnight shipping, did we?).

Sometimes, you just got to "git 'er home".

[chris95040]

Originally Posted by jimbunyard

As an aside, I'm not familiar with this engine, but I think it would be prudent to check that the breathing system is in order. Sometimes they can be a bit arcane, and if not routed or plumbed correctly, pressure can build in the crankcase, which can lead to sealing problems. Won't hurt to double check...especially with a fresh rebuild.

That's a great thought.

[hellosailor]

Then again, he could always try to find a pro mechanic and say "Can you change this gasket and guarantee to stop this leak, without having to pull the engine?"
If the guy says "Yes, $300" that's one answer. If he says "No way" that's something to consider too.

[james247]

Originally Posted by 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.

I agree I would get pretty agitated with a constant drip of oil into my bilge. The smell of oil in the boat is unpleasant. If you can tighten the bolts holding the sump pan can you undo them and drop the pan down.
Or at least get a gap if so with a bit of perseverance clean the seat and get some form-a-gasket into the area and reseat the pan gasket. It isn't under much pressure and shouldn't take much to seal. I can't see how putting anything on the outside will work it needs to be in the joint to hope to be successful.
A finger in the dyke doesn't really work. It's got to be sealed from within

[oldtom]

Originally Posted by Legend61

Thank you everyone for taking the time to help me out, I really appreciate all your inputs, I am looking for ideas and thats what you are giving me.

The more i look at it the more I am considering doing it myself as there MIGHT be room to drop the pan under the engine.

I do have the service manual for the engine, but there is no mention of torque values for the pan bolts or sequence, only torques for block bolts etc. So i will need to hunt more for that info.

Not going to rush into this, have found that pondering the situation for a while usually brings out hidden detail and work arounds.

I had assumed the oil on the bolt heads was weeping out the gasket above the bolts and pooling on them, had not considered that the bolts themselves could be the source of the leaks. Hmmm.

Very reluctant to even consider going back to original engineer for obvious reasons, even if it would be covered under any guarantee, surely this is basic stuff for a mechanic, makes me wonder about the rest of the rebuild!

Anyway still information gathering, so keep any ideas coming.

One guy on a baba 30 next to me during the refit, decided he had enough of engine problems and took his out, sold it and the prop and sealed up the shaft hole, then bought a long sweep oar... sounds a solution!![emoji75]

how much clearance do you have under the sump/oil pan if 25mm or more remove one bolt and go by four longer ones remove four bolts one in each corner fit new bolts remove all the others clean off oil sealant if gasket is not damage reuse apply lictie utre/blue or gray to both surfaces thinly using a finger let dry and bolt up