Ford Lehman Diesel Oil And Filter Change


After a 1,200-mile-plus cruise, engine maintenance is not a to do, it is rather a must do. We did take the opportunity to change oil and filters at the halfway mark, but a thorough change of all filters, as well as an oil change, was high on our list. So I thought I would share the experience with you and give you some insight on how we approach this sometimes messy chore.

An attempt to clean the gunk out of the bowl in the Racor 500 filter housing resulted in a stripped thread on one of the bolts that attaches the bowl to the housing. Of course, that resulted in the filter housing leaking diesel into the bilge, aft of the engine, so a replacement was required. As luck would have it, we purchased all of the parts to install a fuel-polishing system for the engine and have been carrying all of the parts with us for several months now. A new Racor filter housing was sitting in a box waiting to be installed, including all of the needed fittings and replacement 5/16 fuel lines. With the housing replaced, a section of the copper fuel line, from where it was attached at the old filter to the tee that connects both of our fuel tanks, was also replaced. I had not planned to start this yet, but at least all of the material was on hand. Once the housing and lines were installed, the filter was filled with clean diesel fuel. I prefer to fill the filter from a small container rather than try and fill it using the engine's fuel pump. Before securing the lid, all of the new gaskets in the lid are wetted down with some diesel fuel. I use a generous number of oil absorbent pads under all of the areas I am working on to keep the fuel and oil out of the bilge and from getting all over everything.




Next, I turned my attention to the secondary fuel filters on the engine. These are twin filters and are the original style that comes with the Ford Lehman 120. To remove the filter, a plastic knob on the bottom of the housing is removed. At the same time, the securing bolts on the top of the filter is removed. With this, the filter and the bottom section or the "bowl" is removed. There are gaskets inside both the lower section and the upper mount that must be removed, as well as a small O-ring at the head of the securing bolt. Here is where problems can sometimes arise. If you look closely, you will see that the two sealing rigs or gaskets are not the same size if you are using the correct filter elements. Be sure that the slightly smaller one goes into the bottom, or the "bowl," and the larger one in the top. If they are reversed, chances are good that you will have a leak and have to start all over again. Wet each of the gaskets and O-rings with diesel before re-installing them. Slide the securing bolt back on, slide the filter element over the securing bolt, slide on the bottom section, and tighten the securing bolt until everything is nice and snug. Be careful and don't over-tighten. Now move on to the send filter if you have the dual unit.





The engine instructions say to use the fuel lift pump to bleed the engine before starting. This can be time consuming and tedious and I have not had to do that with any of the filter changes. What I have done instead is to remove the bleed screw from the top of both housings. I have a small funnel that will fit in the hole for the bleed screws. I fill the filters from a small container until fuel runs out the top of BOTH housings. Then, the bleed screws are reattached. Once both filters are full, I can start the engine, check for leaks and make sure there is no air in the system. At this point, the engine is run long enough to bring it up to temperature. This is in preparation for the oil change and makes the oil flow better for removal. It generally takes about 20 minutes of running to be sure there are no fuel or air leaks and to get the temperature up.





Once the engine is shut down, the first thing I do is to replace the filter. This is also the messy part, but the spillage can be minimal. The first thing I do is to take a screwdriver and punch a hole in the top of the filter. No, you did not read that wrong. This will allow most of the oil in the filter to drain back into the engine and leave only a small amount to spill once the filter is removed.





Our filter is mounted on a small L-shaped bracket, and by loosening that bracket, I can rotate the filter so it is turned on its side. This allows me to catch all of the oil rather than having it spread out and leak from under the entire filter housing. Here, too, I put oil absorbent pads under everything.





The bolt in the bracket is tightened just a bit to hold the filter in this position.





The next step is to loosen the filter. For this, I like to use an adjustable strap wrench and just use it to break the filter loose. The filter can be removed the rest of the way by hand. I like to wear vinyl disposable gloves to keep my hands clean during the process.





With the filter just loose, it should not yet drip any oil. I use plastic sandwich bags big enough to hold the filter to also catch most of the oil that is still in the filter. By placing it just under the bracket, I can accomplish this.





Once the filter is removed, it is placed in the sandwich bag and sealed to keep from spilling. It can then be disposed of properly without making any more of a mess.





The housing is wiped down and is ready for the new filter. Before attaching the filter, the O-ring is wetted with engine oil to help it seal and get the filter back on by hand tightening. I never use the strap wrench to tighten the filter. The L-bracket is loosened and returned to its original position.





The filter part of the change is done and now the oil has to be removed.





Have I mentioned how much I really, really like our X-change-r oil changing pump. Our oil changes have gone from a messy, time-consuming chore to a quick and easy maintenance item. The reversible pump on the Model 912 allows the oil to be drawn out of the bottom of the sump via an attached line in the bottom drain in a matter of a couple of minutes. Remember to warm the engine up to temperature before extracting the oil.



With the dedicated line from the X-change-r in an empty oil container, a flip of the switch draws the old oil into it, and in a matter of a couple of minutes total, all three gallons of the 30-weight oil is extracted from the crankcase. No mess, no fuss and no spilled oil to clean up. We do keep oil absorbent pads on hand just in case there is an accident. This is a boat so stuff happens.


With all three gallons extracted, the process is reversed, and with a flip of the switch on the changer pump in the opposite direction, the new oil is pumped into the crankcase. Once again, this is accomplished in a matter of a few minutes and there is no oil spilled on the engine or anywhere else. The exact amount is added drawing from three one-gallon containers. Once finished, the pump is shut down and the empty oil jugs are saved for the next change. We always dispose of the old oil in a recycle drum. Most marinas now have these, or you can take it to an auto repair shop.





The next item is changing the oil in the fuel-injector pump. This is something different for us as our former Yanmar and Perkins engines did not require this. According to Bob Smith at American Diesel, and our engine manual, this oil should be changed every 50 hours. I have to admit, we have not stuck to the 50-hour schedule, and it get changed about every 100 hours. We have been told that if the engine begins to idle rough, it might be an indicator that the oil needs changing.





The first step is to remove the fill plug at the top of the pump. Be careful not to mess up the slot in the plug. It has been recommended by some that O-rings be put in each of these plugs and replaced each time the oil is changed. Our pump has copper washers in each plug.





Next, the overflow plug has to be removed. If a lot of fluid comes out when the plug is removed, you probably waited to long to change the oil or you have other problems and fuel is mixing with the oil. This plug plays a part in the filling process.





The drain plug is on the bottom forward section of the pump. This is directly over the raw-water pump and there is not a lot of room to place something to catch the oil. We loosen the plug just a bit, but  it does not leak oil until it is loosened quite a bit. Here, an absorbent pad is a must since it is really hard not to spill a bit.




I use a small Tupperware container that is just small enough to fit between the injector pump and the water pump which will hold all of the oil from the injector pump. It also gives me enough room to finish removal of the drain plug. Once it is completely drained, the container is carefully removed and the drain plug replaced. With the small funnel I use to fill the fuel filters, the pumped is filled with oil until it runs out the overflow in the side of the pump. The plug is replaced for the overflow and the filler plug in the top of the pump is also reinstalled. After a good wipe down of everything, the engine is ready to be restarted. With the engine running, the oil and fuel filters are all checked for leaks as well as the plugs in the injector pump. If all is well, the engine can be shut down, the final clean up done and we are ready for more fun with the boat. No muss, no fuss.

37 comments:

  1. Hello,
    I have a "Marine Trader" with a "Ford-Lehman 135" and I read with interest your text on the maintenance of your engine.
    I have two questions:
    1 - I plan to soon install a pump system for oil changes. Did you do good research on the different models available on the market (Impaller or not), 1, 2 or 3 ports for engine, transmission and generator etc. ...
    2 - Why do you remove and change your oil filter before draining the engine oil?

    Thank you in advance for your response.

    Jacques,
    abord "Côte-de-Nuits"

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  2. Jacques, I did a lot of research on the oil pump and found the X-changer-R gave the best bang for the buck. In addition, as a marine service tech, I have installed many of these systems over the years with good results and the owners were very happy with them. I am sure there are others out there that will work as well, but I have no experience with them. The X-changer-R can be had in several models depending on your needs. Ours can easily be changed to accommodate a generator when we get that installed.

    As to the filter, this has just always been my practice and it helps to remove just a bit more oil that the pump might miss. I suppose it would be a matter of personal choice as to what order it can be done.

    I hope you find the info on the blog helpful and let me know if you have any other questions. Chuck

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    1. what type of transmission fluid is required on a ford lehman 120 hp with borg warner tranny.

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    2. We don't have the Borg Warner, ours is the Paragon. There are several types of Borg Warner transmission so the fluid would be based on the model and year of the transmission. The important thing with adding any fluid is that you don't mix one kind with another. Consult your transmission manual and if you don't have one a Google search should bring up what you need. Good luck, Chuck

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    3. Sorry if this is a double entry, on phone. Borg specifies ATF for the tranny, though later they published engine weight oil if the owner preferred. I thought the PO was nuts when he handed me a case of atf, but he was right.

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  3. Wow, great information. I have twin Ford Lehman 120s in a boat I bought recently and I need to do all of the above to get ready for our first trip south this Fall. Your photos and commentary will make this a snap. Thanks Chuck!

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  4. Pam and Dave, The FL 120 is a great engine and easy to maintain. It looks like we sort of have the same plans for the future. Good luck to you both and maybe we will meet somewhere down the road. Glad the posts help. Chuck and Susan

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  5. Chuck -
    1. Thanks! Great photos as always.
    2. I am in a bit of a quandary. I've run about 200 hours in my FL135 since buying it. I missed changing the oil in the FI pump! Thanks for this.
    3. My engine is canted up so that the oil level does not read high enough on the dipstick. I have added oil and had a high level last fill, so I matched it. So either a) I need a longer dipstick or b) I need to fill to a lower line. Having a mismatched dipstick wouldn't be the first surprise I've found from the prior owner...
    What's the risk in over-filled oil?

    Thanks,

    Ben
    35 MT Sand Castle
    New Bern

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  6. Ben, As to the overfill of oil, One severe problem would be creating a “RUN-A-WAY” diesel.
    This occurs when the oil level would be high enough that the crank and connecting rods would splash the oil in the oilpan. This splashing can create an oil mist or vapor that can be drawn into the cylinders on the intake stroke, around the piston rings or other paths, creating an unregulated fuel source for the engine. Small amounts would probably not result in this behavior.

    What you need to do is pull the dipstick the next time you do an oil change and remark it using a Dremel tool or even a hack saw. Be sure you have added gallons exactly as your engine calls for, and about a half quart for the filter. Let it all sit for a while to settle in the crankcase and then remark the dipstick. This is now your full mark. Many engines are marked this way when first installed but I doubt yours or mine was. If the dipstick does not reach the oil at all, I have never seen this, than perhaps you have the wrong dipstick, Contact American Diesel and they will get you the proper one. Good luck. Chuck

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  7. Thanks, as always, for the informative posts. We are looking for an injector removal tool for the Lehman 120 in our MT 34. Any ideas? American Diesel doesn't have it.

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  8. Sarah, I am really surprised that if American did not have it, Brian or Bob did not give you another source. However, you might try Bomac Marine. You might have to copy and paste this address to your browser. http://www.bomacmarine.com/ . Good luck. Chuck

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  9. Chuck, thanks so much for the suggestion for Bomac--they were very helpful and knowledgeable! Back in the bilge for more battles!

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  10. Sarah, Glad I can help. Have fun in the belly of the beast. Chuck

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  11. Hi Chuck,
    This really is great info, as is the rest of your site. I just bought a 1983 Cheer Men PT 41 with twin Lehman 120's. I also have the same fuel filter setup as you. I was able to change the two primary's just fine. After completing the secondary engine filters I tried to pour fuel in through the bleed screw and it doesn't seem to work, it just instantly overflows...but the filters/bowls are empty. Any tricks or advice? My port engine has the old lift pump by-passed and the fuel goes through an electric pump. I have been able to previously turn the key on to get the pump running and use this method to bleed both filters and the injection pump. Having some trouble now that I have installed the new filters.

    I used NAPA 3166 filters. They came with two small rubber gaskets (screw and inner housing) and three large gaskets, 2 the same size and one slightly larger. It seems I don't need all three, just one of the slightly smaller and the larger. does this sound right? I still seem to be getting some leaks so likely need to play around more.

    Lastly, at least one of the white plastic knobs on the bottom of the filter bowls is pretty stripped and now leaks since I changed the filters. I am going to try American Diesel, but wondered if you had any guidance here as well.

    Many Thanks in advance,
    Donny

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  12. Donny, I'm not sure why you are having problems filling the filters except that I don't use anything but the correct filters for the Lehman which I get from American Diesel. The problem may be that you are filling the funnel too fast. If the fuel fills the funnel but air is trapped in the filters and housing, the fuel will only fill the funnel. You need to pour it slowly and let air out as the fuel goes in. The way you can verify that this is the problem, is if you have the funnel full of fuel and it won't go into the filters, wiggle it a bit. If the fuel goes down, this is the problem. I suggest you speak with Brian or Bob and I am sure they will give you the straight scoop. The gaskets for the Lehman filters are two different sizes and if you get the smaller one in the top and the larger one in the bottom, it will leak. Also wipe the gaskets down good with some diesel fuel before you install them. You have to be careful in replacing them and make sure they are properly seated. It's easy to get them twisted or misaligned. Leaking is a common problem using some cross referenced filters. The plastic knob is also a common problem. You can temporarily fix this using the correct Stainless steel nut with a plastic washer. Just be careful and don't make it too tight. Good luck and call Bob or Brian. They are a wealth of information. Chuck

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  13. Hi Chuck,
    great hints from you guys for properly working on our reliable engine. Please confirm the oil for the fuel injection pump is the same as for the engine,30 weight.do you have a rough figure of how much oil would be required?
    thanks for your kind reply
    Roberto Gavagnin
    SY ZARA

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    Replies
    1. Roberto, Yes the injection pump uses the same 30 wt. oil as the engine. I have never actually measured it. I just fill until it comes out the overflow, but I would guess it's only about a pint or so. Thanks, Chuck

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  14. Chuck,
    Really enjoyed your step by step and I followed it faithfully. I have twin FL120s that I have had for about a year. Several months ago the Stbd engine started acting differently. It would not come up to speed loaded. The throttles tracked evenly up to about 1500 rpm and then the stbd climbed much more slowly. Can get about 2300 out of the port engine and 2000 out of the stbd engine. Replaced the lift pump thinking that might have been the problem but no change.. Any thoughts what I might look at next. Thanks.
    John Parvis
    Dream Weaver

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    Replies
    1. John, Unfortunately it could be a number of things. I'm sure you have already changed all of the filters. The problem can be as simple as a clogged pick up tube in the tank to a problem with the injector pump or injectors. I would suggest a call to American Diesel and speak to Brian or Bob, They can and will offer the best troubleshoot advice you will get. The next step then will be a mechanic if that doesn't resolve the issues. Be sure and get a mechanic that is familiar with the Ford Lehman. One other suggestion. Check the props and make sure they are clean. Chuck

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  15. Thanks for the pics and info...came in handy with our own engine.

    Cheers!
    Erika

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    Replies
    1. Erika, Your very welcome. Happy we could help. Chuck

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  16. Hi Chuck - you said this:

    If you look closely, you will see that the two sealing rigs or gaskets are not the same size if you are using the correct filter elements. Be sure that the slightly smaller one goes into the bottom, or the "bowl," and the larger one in the top. If they are reversed, chances are good that you will have a leak and have to start all over again.
    =====================================================
    I think I have botched the filter installation. I can bleed the system, then start engine, but it quickly dies. I checked the manual and bled the system to the injector pump. Runs a few seconds and quits. Should I just go and reinstall new filters as I have taken them on and off a few times? Could I have warped the O-Ring?

    Perplexed.

    Probably call a mech to walk me through best practice.

    Ben

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    Replies
    1. Ben, Sounds like the system is still not completely bled and has air. Are you sure both filters and your main Racor is full before starting to bleed? If there is still air in the lines it will cause a shut down. Start with the Racor, make sure it's full. Move to both secondaries and make sure they are full. I take the bleed bolts out of the top of the filters and fill them manually until fuel runs out of BOTH. Then bleed to the injector pump. You can't just have fuel coming out, you need to be absolutely sure all the air bubbles are out. If the O rings are wrong, you will see the filters leak. Also look for the obvious. I have forgotten to open the fuel valve on the tank on occasion. You might also try and crack the injector lines and turn the engine over until fuel is coming out and no air. Good luck. Chuck

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    2. Thanks Chuck, I am not seeing fuel come out, but I will return to the Racors again and start. I have fuel when I pull the bleed bolts. Coming out like crazy. Need a bit of capturing pan for the diesel. I think in some way my secondary filters may not be seated right. How best to bleed injector pump? I opened early and some air came out, but has been all fuel.

      I am thinking the spin-on filter adapters will reduce the probability of trapped air. Was going to call Brian at American Diesel next.

      Thanks for your help. Especially because our engines are very similar!

      Ben

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    3. Brian will be the guy to help you. It's hard to troubleshoot when not in the engine room. When you have it worked out, come back and let us know. Chuck

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  17. If you are still looking for the injector pump tool/wrench, Dan at D&L diesel in fort Myers can get one. He borrowed it from performance marine(?) in Fort Myers due to a leak at the base of one of mine just a month ago. Replace the seals on all. Also I have a big thin wrench for the injector nut on the head.

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  18. Chuck,

    We just bought a 42' 1968 GB woody. Twin FL 120's. Your pictures and narrative was a great starter for a neophyte engine room monkey like me. I've not been able to find a satisfactory answer to the question - what's the right rpm for my engines? The guy I bought it from never liked to go over 1200rpm. We brought it from below Savannah to Charleston around 1500-1700 and it seemed to run fine - water temp and oil pressure rock solid. What's your opinion?

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    Replies
    1. Randy, Your right in the ballpark. It really comes down to fuel conservation. We typically run Beach House at 1700 to 1800 RPM's. If we're in a hurry, we run at 1900 RPM's, but we use more fuel. 1200 RPM's is a pretty leisure pace. You should run it at wide open throttle for about 5 minutes on each days run to clear out the engine. It will also tell you if you have any issues. Good luck and enjoy the new boat. Chuck

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  19. Looking at a 40' Marine Trader handyman special with twin FL 120s. The marina is basically a junkyard and will not do anything to assist in checking engines. Port engine has milky oil and starboard engine appears to be seized. There are no batteries on the boat and before I go further, I want to see if I can get them to crank. My hope is that the water in the oil is from years of condensation building up inside but on the other side of the coin, the engines might be blown. Can you give me a step by step on how to prepare the engines for starting? I want to make sure that whatever should be done prior to hooking up batteries and trying to start is done before I crank them so I don't run the risk of possibly causing more damage.

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    Replies
    1. If it were me, I would walk away, even if this was free. The engine problems can be anything from a blown headgasket to a cracked block. If it has sat with water or moisture in the cylinders, then the internal parts including the cylinder walls are rusted. If it hydrolocked while running, everything inside is probably broken. You can't salvage this. The only option would be engine replacement. At the very least, you will need to pull the heads, soak the pistonsans cylinders in transmission fluid, then oil and then try to turn the engine over by hand using the large nut on the front engine pulley and a large breaker bar. If it won't turn over by hand, pack up and move on. At least that is my opinion. If you can find a local diesel mechanic that will give you some additional tips, it might help. Good luck. Chuck

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  20. Chuck - first let me say your blog is a maintenance dream for any FL owner and I thank you for all the work you've put into it! I was reading this section and had on idea about the injector needing an oil change. I just bought an older Grand Banks about 18 months ago. The engine runs great, running right at 180 degrees and 40-50 LBS of oil pressure all the time. It made the voyage from the Toms River (where we bought it) to the York River (where we moor her) without a problem. We started off from NJ having done all of the maintenance items I knew about and I've since taken off all the heat exchangers and taken them to a local radiator shop and had them cleaned and tested. Anyway....I changed the injector oil this weekend and I suspect it's been quite a few hours since this was done. I did find it was primarily filled with diesel and filled way past the overflow plugs. Is that normal when the oil change has been let go so long or do I have more serious issues at hand? Thanks! John

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    Replies
    1. John, We're happy to hear you find the blog useful. Diesel in the FL injector pump usually means that seals are leaking. How bad the leaks are depends. I would change the oil in the injector pump in 50 hours and see what you have. If no diesel or just a smell and no excess, wait another 100 hours and change again. If at that point you find a lot of diesel, it's time for a rebuild. This isn't an inexpensive repair but very doable. Be certain you find a shop that is very familiar with this exact injector pump. Be very careful with the drain and overflow plugs. It's very easy to over tighten and strip out the threads. Some manuals for the 120 say to change the injector oil every 200 hours and some say 50. We changed ours about every 100 hours or the same time we changed the engine oil. There was always a faint diesel smell. Good luck and we hope everything works out well. Chuck

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  21. Thanks for the quick reply Chuck. That was my thought too, to change the oil around 50 hours or even sooner just to see if it was full of diesel again. Appreciate the insight on why the diesel gets in there and what the fix is. We're lucky to have quite a few diesel shops in this area and we're pretty close to American Marine where we live so if I need the injector pump rebuilt, I'd probably ask them for a recommendation. This is our second wood GB, we had a 1966 when we lived in Seattle and bought a 1972 model after moving out to VA and finally getting back into boating (kids soccer took center stage for a while). I never knew about the injector pump oil change the whole time I owned my other one. Thanks again! John

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    Replies
    1. Enjoy getting back on the water. Don't change oil too soon, but maybe remove the overflow plug at about 25 hours to see if you have any excess diesel in the mix. Give it time to lubricate everything. Most importantly, have fun. Chuck

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  22. It was a pleasure to find your blog, it's a useful and enjoyable place to visit ! Thank you !!
    My question/issue is this : About 4 months ago I bought an 85 Grand Banks 36CL in Miami and moved it home to Charleston, SC via the ditch. The oil/filters were changed before the trip. No issues. I then moved it to New Bern, NC, and again had the oil changed. The issue: the mechanic said the starboard Lehman 225 Turbo has approx. 1-1.5 gallons less oil than the port. He said (of a largeish) oil trail down the engine mount rail was that it was "excessive blowby" and the reason for the oil difference. After cleaning things up, I noticed that the oil appears to be dripping from the turbo charger, not the blow by (?) tube. Is this possible, or am I way off base ? If so, 1)how serious is it ? 2) whats involved in fixing it, and 3) is it expensive ? Would such a leak cause the oil difference I described ?
    Again, thank you for your time and all the help you give us novices !

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    1. Steve, While it is possible, a gallon to a gallon and a half seems a lot, depending on how many hours you have run. It's impossible to troubleshoot or guess about the issues without being on site. I would suggest you contact a mechanic that is familiar with the FL and turbo engines and have them do a thorough analysis. The mechanic that "diagnosed" the blowby should have looked into the problem more so I would not put a lot of stock in his assessment. Good luck. Chuck

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While we always appreciate feedback and comments, comments are moderated to keep out the spam. SPAMMERS, DON'T WASTE YOUR TIME. There are pretty much two rules. NO LINKS or URLs in your NAME or the POST, and BE NICE. There is enough negativity out there. If either of these are not followed, your comment will not get posted. Thanks, Chuck