Ford Lehman 120 Bad cylinder

[mplangley]

I have a Grand Banks 32 with rebuilt ford lehman. It has about 1800 hours on it. My mechanic said today that one of the cylinders/pistons is bad.

Does any one have any experience with this? Im wondering if the engine will need to be removed or whether it can be lifted in the boat and redone there.

thx

 

[BruceK]

Which cylinder is it?

 

[Capt.Bill11]

Depends. And it's pretty rare for a Lehman to need a rebuild with so little hours on it.

I bet he says it's the number 6 cylinder?

 

[Ski in NC]

What symptoms is it showing?

 

[mplangley]

It is the first or last cylinder - the cylinder nearest the stern.

The symptoms were excessive blow-by. Also the mechanic did a check whereby be listened for engine idle change as he loosened the injectors. When he loosened the cylinder nearest the stern no changes were noted however as we tested the others the idle speed changed.

So I am trying to figure out what my options are and what to expect and am wondering if the engine can be lifted and repaired right in the boat.

thanks for any insight into matter.

 

[what_barnacles]

You can bore it in the boat but you need to find a mechanic that has the portable boring jig.

 

[Busterbrown]

Engine Savers in Chino, California ask for Dan

 

[av8r]

You could have your mechanic swap the #6 and the #5 injectors and repeat the test to rule out a bad injector. You could also get a diesel compression tester and confirm the #6 cylinder is low, $850 from Snap-on or $169 from Harbor Freight.

 

[gaston]

Id also be testing the manifold temperature on the 6 cylinders and comparing the results and insert a little camera down the injector hole and have a look at the cylinder wall and compare it to another cylinder

 

[stanfromhell]

Excessive blowby and one dead cylinder may be caused by
1- A hole in the piston, likely caused by a stuck injector
2- Broken rings

 

[BruceK]

I`m interested in why, and why no.6(as expected)? Fortunately we have some experts on the thread. My understanding, as a Lehman owner who bought mechanic time flushing one of mine, is overheating at no.6 due to poor cooling, due in turn to sludge blocking the cooling passages.
Interested to hear more, hoping the OP`s engine can be efficiently repaired. Was the past rebuild before the OP bought, or are details of the need for rebuild known?

 

[FF]

"The symptoms were excessive blow-by."

Excessive blowby and no compression are different animals .

My guess would be stuck rings . A couple of long hard runs with very fresh oil might help.

The outboard folks have super cylinder cleaning products that actually work and might free the rings if that is the problem.

If the problem is mostly at idle and there is no billowing white smoke , ot rapid lube oil consumption, live with it.

It might cost an extra cup of fuel an hour or a quart of oil between changes , so what?

Heaven might be "perfect",,, but for a cruising diesel reliable IS perfection.

 

[Mule]

Any thoughts about injecting a few tablespoons of Marvel Mystery Oil into the offending cylinder to try to free things up. Doubt if the voodoo will work but maybe if you chant and face Haiti. Injector out anyway so why not?

On such issues I defer to FF. On this one I am adding to and building on his diagnosis.

 

[Xsbank]

The number 6 cylinder fails on some Lehmans. It's always number 6 and it's a cooling issue. I have not heard it satisfactorily explained why it fails but there is conjecture the angle of the engine mount and the distance from the water pump, failure to regularly "burp" the coolant jacket, the distance from the Simms pump perhaps causing slight lean conditions, not regularly changing the coolant...
Anyways, that cylinder overheats, the oil breaks down, the cylinder walls are badly scored and the piston leaves large amounts of aluminum on the cylinder walls. You will see the damage with a boroscope.
In a 32, the engine comes out through the back door. You can do it in place but you'll get a better result in a shop. You can also buy rebuilt from places like Industrial Engines near Vancouver, BC if you don't want to wait for the rebuild.
Sorry. I have heard of three that failed like yours.

 

[jleonard]

The number 6 cylinder fails on some Lehmans. It's always number 6 and it's a cooling issue. I have not heard it satisfactorily explained why it fails but there is conjecture the angle of the engine mount and the distance from the water pump, failure to regularly "burp" the coolant jacket, the distance from the Simms pump perhaps causing slight lean conditions, not regularly changing the coolant...
Anyways, that cylinder overheats, the oil breaks down, the cylinder walls are badly scored and the piston leaves large amounts of aluminum on the cylinder walls. You will see the damage with a boroscope.
In a 32, the engine comes out through the back door. You can do it in place but you'll get a better result in a shop. You can also buy rebuilt from places like Industrial Engines near Vancouver, BC if you don't want to wait for the rebuild.
Sorry. I have heard of three that failed like yours.

And I was warned of this possibility from overheating by more than one "experienced timer" when I told them I had a Lehman 120.
The temp sender is on the front of the engine, so the back of the engine may be hotter and you won't know.
This is one of the reasons I am a little over anal about maintaining the raw water system, changing impellers too often, etc.,

 

[mplangley]

"The symptoms were excessive blow-by."

Excessive blowby and no compression are different animals .

My guess would be stuck rings . A couple of long hard runs with very fresh oil might help.

The outboard folks have super cylinder cleaning products that actually work and might free the rings if that is the problem.

If the problem is mostly at idle and there is no billowing white smoke , ot rapid lube oil consumption, live with it.

It might cost an extra cup of fuel an hour or a quart of oil between changes , so what?

Heaven might be "perfect",,, but for a cruising diesel reliable IS perfection.

Is there any risk of further damage by a couple of long hard runs? I was wondering the same thing, namely whether a cylinder cleaning product may work.

I don't know that there is "no compression" but I do know there is excessive blow by and there seems to be insufficient compression for combustion. I will see about following up with a compression check but my mechanic seemed to think it was not necessary as he was pretty convinced that it was a bad cylinder issue.

 

[mplangley]

"The symptoms were excessive blow-by."

Excessive blowby and no compression are different animals .

My guess would be stuck rings . A couple of long hard runs with very fresh oil might help.

The outboard folks have super cylinder cleaning products that actually work and might free the rings if that is the problem.

If the problem is mostly at idle and there is no billowing white smoke , ot rapid lube oil consumption, live with it.

It might cost an extra cup of fuel an hour or a quart of oil between changes , so what?

Heaven might be "perfect",,, but for a cruising diesel reliable IS perfection.

Is there any risk of further damage by a couple of long hard runs? Also I was wondering the same thing, namely whether a cylinder cleaning product may work or is this just wishful thinking?

I don't know that there is "no compression" but I do know there is excessive blow by and there seems to be insufficient compression for combustion. I will see about following up with a compression check but my mechanic seemed to think it was not necessary as he was pretty convinced that it was a bad cylinder issue.

 

[Ski in NC]

Does blowby "puff" each time that cylinder should fire? If blowby puffs in sync with one cylinder firing and that cylinder misfires, pretty much nails a piston problem.

Can also take injector out and with valves closed shoot compressed air into inj hole. If pressure does not build and air is going into crankcase, just pull head.

Sometimes pistons screw up and cyl wall is not damaged, or not damaged much. A bit of honing and a new piston/rings and good to go.

I would not run the engine hard in that condition, you could cause more damage.

Makes me wonder if during your last rebuild the piston/bore clearance was a bit too tight. If that cyl 6 tends to run hot, you want the clearance on the loose side of spec. And honing will get you just that.

Solvent like two stroke outboard "ring-free" may be worth a try. I have unstuck rings with that before on a diesel. But don't run engine hard unless the compression comes back and blowby goes to normal.

 

[mplangley]

Does blowby "puff" each time that cylinder should fire? If blowby puffs in sync with one cylinder firing and that cylinder misfires, pretty much nails a piston problem.

I would say yes. Nice billowy white puffs.

Do you think there is any harm in trying marvel mystery oil or "engine restorer" just to see what effect it has or is this a waste of time. I'm just thinking that if engine restorer brings compression up enough that the piston fires then that may help determine whether honing the cylinder would be sufficient.

 

[FF]

Mystery Marvel oil is #1 diesel, some coloring and oil of wintergreen to change the aroma.

Removing the injector to swap it with a different cylinder will allow both to be hooked to a compressed air source to see a difference.

 

[Xsbank]

Take out the injector and look in there with a boroscope. Even Home Depot sells them. Damage will be obvious.
Call Ken Bowles at Northwest Charters Grand Banks sales in Seattle and ask him about his number 6. Or ask on the Grand Banks site - Bob Lowe keeps a pickle where the sun doesn't shine but he has good info.

 

[Nomad Willy]

Trouble w putting solvents in the cylinder is that diesel pistons are usually dished. Pouring solvent in just puddles in the bowel unless you fill it and then if you crank the engine you've got a 55-1 compression ratio.

If you know the injector is over the bowel or depression you can put lots of solvent in and let it sit. If it leaks by the piston skirt you'll have solvent in the oil but depending on the solvent it should'nt be a problem if only very temporary. I would do that and use SeaFoam as the solvent. Risoline is the same product or close enough. I used that stuff to free up rings on old outboards years ago.

I can't believe nobody has come up w a fix for the overheating #6 cylinder. If I had an FL I'd sure tru something.

 

[BruceK]

Here`s the advice I`ve received:
AD advised that in a bad case of sludging remove the drain plug in the block near no.6 to assist flushing. (Mechanic says "drain plug" is what Aussies call "welsh plug"[no disrespect to the Welsh]. Seems a quite aggressive approach.) Mechanic says use good coolant, dilute coolant concentrate with distilled water, flush and change coolant if necessary.
Of course, no.6 is also furthest from the FW circulation pump.

 

[psneeld]

I asked the same question this past fall about sludge and got the "it's rarely a problem" and not worth pulling the freeze plug back there....

Straight from AD.

So who knows.

Every year it seems that more and more conflicting info gets passed around about Lehmans.

 

[Capt.Bill11]

Here`s the advice I`ve received:
AD advised that in a bad case of sludging remove the drain plug in the block near no.6 to assist flushing. (Mechanic says "drain plug" is what Aussies call "welsh plug"[no disrespect to the Welsh]. Seems a quite aggressive approach.) Mechanic says use good coolant, dilute coolant concentrate with distilled water, flush and change coolant if necessary.
Of course, no.6 is also furthest from the FW circulation pump.

A more effective way to flush your coolant system is to use Cascade dish washing liquid. Cleans out a dirty coolant system very well with little or no foaming action.

 

[Capt.Bill11]

I asked the same question this past fall about sludge and got the "it's rarely a problem" and not worth pulling the freeze plug back there....

Straight from AD.

So who knows.

Every year it seems that more and more conflicting info gets passed around about Lehmans.

All I can say is I've personslly cleaned out a lot of sludge from neglected Lehman cooling systems over the years.

 

[BruceK]

My recollection of the email advice from AD was that removing the drain plug could be done in an extreme case of sludge build up. Hope that helps put it in context.

Edit. I just found the 11 January 2013 email from Brian Smith: " The "silt" in the fresh water system has me concerned the most. Flushing the block is exactly what I would recommend to do. In an extreme step,the rear freeze plug on the block can be removed to determine if sediment is accumulating at the back of #6 cylinder."

 

[stanfromhell]

If you think your #6 cylinder may be overheating, go to your auto parts store or Harbor Freight and purchase an infra red thermometer for about $25.00. Run your engine untill it is warmed up and take a temperature reading of the block about three inches down from the cylinder head/block joint. Start at #1 and work back to #6 about 6 inches at a time. If the water passages at the rear cylinder are plugged you will see much higher temperatures where there is no water flow. Do not be alarmed if there is a gradual increase in temps from front to rear because of the increasing distance from the circulating pump.

 

[what_barnacles]

just take the freeze plug out on the back of the block and look

 

[mplangley]

Thanks for all the input. It has given me much to think about.

I think my approach will be to try some miracle snake oil first and then once that fails I'll remove the head to get a visual inspection of the piston and cylinder. At that point I'll hope to find some frozen but repairable rings per FF's suggestion and maybe I'll be able to hone the cylinder in place.

I'd be happy to just live with it (for a while) but I am worried about two things. 1) the oily mess it makes out the breather tube and filter but also 2.) more importantly what further damage it may due to the engine?

There seem to be mixed views about what additional damage can come about by running the engine with a bad cylinder. Anyone have any additional input on that. I took the boat out today and kept her at sub 1700 RPM's and but for the additional smoke and oil she did great.

I tend to agree with what FF said above "Heaven might be "perfect",,, but for a cruising diesel reliable IS perfection.". Reliable is good enough for me but I don't want to destroy the engine. Come winter I can take her out and address the engine at that time.