Ford Lehman survey issue help

Looking to purchase an 83 Grand Banks Motor Yacht with twin Ford Lehman 120 engines.
During the engine inspection evidence of coolant leakage was discovered coming from the Head Gasket area. I also noticed that the current owner had a carton stored in the engine room that had at least 5 gallon jugs of premixed coolant stored. The mechanic said that coolant leaks for the Ford Lehman 120 diesels are common and specifically that the head gasket leaks were minor and not worth chasing down to repair. He explained that the engine has a design flaw that can lead to these small leaks. Sounds strange to me but I am not familiar with these engines. The large quantity of stored, pre-mixed coolant also bothers me and I am wondering if I am getting played a bit on this issue. Would appreciate any advice or comments.

Following

Call Brian at American Diesel. He is THE guru on FL engines. His father was involved with marinizing the Ford engines and then started AD. 804-435-3107. He is very willing and capable to help.

Seems like horse ****!

Leak oil, yeah, but coolant...!

My Sp275 only loose coolant if a hose isn’t tight enough.

In addition to Brian, you can also ask the folks on the Grand Banks Owner’s website.

Google it.

Coming from 29 years of maintaining a pair of those beauties, I am going to raise my voice a little so cover your ears. GET ANOTHER MECHANIC BECAUSE THAT GUY IS FULL OF SH__! Any FL120 doing that needs serious attention.

Greetings,
Mr. WGL. I've never heard of any "design flaw" that precipitated head gasket leakage on the Lehman 120. That being said, I am NOT a mechanic. The "large quantity of pre-mixed coolant doesn't really bother me, at all. Presently, I have 5 gallons of Auto Transmission Fluid, 5 gallons of SAE 30 oil and 3 gallons of pre-mixed AF aboard in anticipation of fluid changes (as soon as this COVID business is over and done with).

Coolant leaking from the head gasket is NOT normal or acceptable as a “known” issue.

Ken

I have never heard of any design flaw in heads. If some previous owner removed the head and didn't torque it down properly, or overheated the engine, the head may be warped. There would be a noticeable leak once you reached operating temp. It could drain to the exterior, or into a cylinder resulting in a lot of steam out of the exhaust while running. A warped head needs to be repaired.

Removing the head is a straight forward job for anyone with some mechanical experience If you are limited to changing the oil annually, then get some quotes. (If I removed the head on a high hour engine I would be tempted to do a valve job at the same time.)

I also keep a few gallons of pre-mix on board along with ATF and Rotella.

I have had my boat for 4 months now and I have done extensive research on the 120’s. I have never heard of a design flaw of this type. The 120’s are pretty much bulletproof, if you keep them maintained. I have over 4,600 hours on mine. I would ask another mechanic about that. Or, yes call American Diesel they are the best!

It might not be the head gasket. There is a metal tube leading down, I think from the header tank(not sure now-sold boat and engine manual with it), which gets eaten away over time, so the rubber hose can`t be clamped adequately, and it leaks. It`s just at head height and led to coolant appearing in the head/block joint. Looked so much like head gasket leak I bought one, but never used it. You replace the failing tube by welding on a fresh section, it`s aluminum I think. This happened to both my engines so I assume it`s a known occurrence.

BruceK said:

It might not be the head gasket. There is a metal tube leading down, I think from the header tank(not sure now-sold boat and engine manual with it), which gets eaten away over time, so the rubber hose can`t be clamped adequately, and it leaks. It`s just at head height and led to coolant appearing in the head/block joint. Looked so much like head gasket leak I bought one, but never used it. You replace the failing tube by welding on a fresh section, it`s aluminum I think. This happened to both my engines so I assume it`s a known occurrence.

Click to expand...

If the engines have been properly updated, that tube from the expansion tank was plugged when the new filler neck accommodating a double-acting radiator cap (the original was not DA) with a recovery bottle attached via hose to the new neck's tube fitting.

At my current stage in life, I'd likely be walking away from this vessel. Engines need to be perfect for me to buy.

We have owned and operated 120's for 20 years, with 10,000 hours now and 70,000 NM's of travel and I have never heard of a design problem causing a coolant leak? I don't think so.

Calling Brian is a great idea.

You didn't mention if, and if so where, the leak was? You will see 120's leak some coolant at higher RPM's on the port side of the head gasket just above the starter. If that's the case I'd look at the head bolt torque, but it may be warped. Did it show up a specific RPM?

Good luck,
Jim
M/V Sea Venture

My PO had a suspect amount of antifreeze onboard. Sure enough, I had to top off about every 5 hours. I couldn't find the right fittings to do a pressure test, so I just bought a new cap. Mine isn't the double acting "upgrade" system. The new cap only helped a little. Turns out that the old heater hose to the hot water tank had "checked" within a few inches of the tank connection and sweated out coolant once the system got hot and up to pressure. I replaced that and haven't added coolant for the last 200 hours. Don't expect to.

My simple little problem was $100 and a few hours of diagnosis and repair (i.e., screwing around). Evidence of coolant leakage from the head could multiply that by 20. I would definitely get a second opinion. Then, if I was still interested in the boat, I'd get a third opinion (a tentative quote) from a shop that could do the repair.

Bob Senter of Northern Lights/Lugger/John Deere Marine Propulsion is one of my marine mentors. He once told me there is no such thing as am acceptable leak of any fluid. Diesel, coolant, raw water, oil, etc. None, zero, nada.

You cannot go wrong with that advice. You bear 100% of the risk of your mechanic is wrong. And he is. A head gasket leak on a diesel is a bad sign. There is no way to spin it as normal.

Peter

Surveyor poppycock!

As far as carrying extra coolant that is only good practice.
Not only do I carry extra mixed coolant I also carry one oil change worth of oil.
Of course just how much is up to each owner.

As far as leaks at the head gasket ar concerned the comments , at least to me, are haywire.
Not normal.

However before writing the engine off be absolutely positive it is a head gasket leak. It may not be at all. If a nearby hose clamp is loose or a hose questionable maybe they provided the coolant.

Get another mechanic.

We have ,twin le120 no coolant leaks....add maybe pint to plastic expansion res very infrequently. That much coolant means problems.

I had a FL120 coolant leak only after a long run. Finally traced it to a leak at the buss heater attachment. Need to change hose. Water was not visible until had a look in behind heater. SB coolant goes through hot water tank and the buss heater. After isolating both no more loss of water.

Coolant leaks are not common on any Diesel engine and definitely not on a FL 120 ( I own one). Yes it sounds as if you are being played.

FL 120 coolant leaks

Wild Goose Loose said:

Looking to purchase an 83 Grand Banks Motor Yacht with twin Ford Lehman 120 engines.
During the engine inspection evidence of coolant leakage was discovered coming from the Head Gasket area. I also noticed that the current owner had a carton stored in the engine room that had at least 5 gallon jugs of premixed coolant stored. The mechanic said that coolant leaks for the Ford Lehman 120 diesels are common and specifically that the head gasket leaks were minor and not worth chasing down to repair. He explained that the engine has a design flaw that can lead to these small leaks. Sounds strange to me but I am not familiar with these engines. The large quantity of stored, pre-mixed coolant also bothers me and I am wondering if I am getting played a bit on this issue. Would appreciate any advice or comments.

Click to expand...

"Played" is a kind word for what you are getting here. The advice to call Brian at AD is great advice. Another asset is Grand Banks Yacht Basin in Stuart, Fl. They are a GB repair facility and can probably help as well. But in any case, coolant leaking from the head gasket on an FL 120 is anything but normal. A well maintained FL 120 will provide well over 10,000 hrs of svc. Sounds like this one has not been well maintained.

I own an '84 GB with twin Lehman diesels. Had it for 7 years. I don't agree with what the seller is telling you.

Ditto. Call Brian at American Diesel. He's the expert and will give you an honest assessment.

So, Goose, what is the result?

Not a good idea

Coolant leaking out of a head gasket is not good, no matter what engines you buy or have. The boat will probably not warrant a sale recommendation without the heads being pulled and necessary repair work done.

First of all, thanks to everyone who has responded to this thread. I have spent a lot of time talking with American Diesel, other mechanics and a number of boat owners with these engines and it's still a bit murky. Tri County Diesel out of Bellingham who did the survey has worked with American Diesel on two other similar instances where they were getting coolant "weeping" out of the head gasket at high RPMs but no leakage below 2200 to 2300 rpm. American D says Tri County Diesel has gone above and beyond in trying to stop the high RPM weeping issue and they agree with them that it'snot a big issue and does not expose me to any further serious engine damage. Both Tri and American agree that no one runs these engines above 2200rpm anyway since there is very little speed gain running these engines at that rate and you are just pumping extra fuel in for little if any gain. Further Tri thinks that this issue is much more widespread than most Ford Lehman 120 owners realize because one, the weeping is so minimal and two, since most owners never run at that rate they never see the weeping issue. Anyway, I'm satisfied that it's not something serious and am moving forward. Btw, both American D and Tri County Diesel have been more than cooperative and transparent. I'll keep you advised how things work out over the next few months.⁰

Fl 120

I never run above 1800.

I have a lehman diesel 120. Ive had it for 10 years.

It leaks oil. It leaked a bit if oil before and after I did the headgasket, lol. (just did the head gasket prophylactically when I first bought the boat wihen doing a bunch of other stuff. (Injectors, valve guides etc....)

I think it is leaking from injector seals and valve cover gasket.

That being said, it never leaked antifreeze....... ever. And i run 2400 all the time. (Its in a small 26 downeast )

If it does, you might be able to get by for a while just filling, but its a timebomb. Do the headgasket. I did it in the water in the late fall. Its a simple engine. (Thats why i love it)

The head gasket was rulled out early on as the culprit according to both Tri and American D. I should amend my posting to add that the weeping issue included both oil and coolant traces.

Gotcha. Interesting.

That being said, i used to blow coolant out the overflow at full throttle. Had to top off now and again.

I did the coolant recovery set up from AD and that stopped.
Just FYi

Why would it leak?

I would be concerned that the engine overheated and possibly warped the head. Replacing a gasket but replacing a head $$$$