Logo
FULL SITE MENU

Ford Lehman overheat

J

jeffneville

New member
"I have a 1979 Grand Banks 36

"I have a 1979 Grand Banks 36 with twin Ford Lehman 120's, 6 cyl. The port engine is overheating by 20 to 30 degrees. I have done extensive work to try to find out the problem and at am the end of my rope for a solution.
Here is a summary of the work done - all 3 raw water heat exchangers have been taken off, inspected and back flushed. Then these were exchanged with the starboard engine and still the port engine overheats. The riser has been replaced - the old one didn't show very much accumulation. Engine temperature gauge reads the same at main steering station and bridge station. Also, it has been connected to starboard engine and shows normal temperature. The temperature gauge sensor has been exchanged with the starboard one and there is no change.
The thermostat was replaced but no improvement. The new one has also been exchanged with the one in the starboard engine and no change.
The raw water impeller pump has been rebuilt. The raw water intake has been exchanged with the starboard engine one. No change - the problem persists. Raw water exhaust on port engine looks about the same as the starboard.
The port engine sounds like it is running well - sounds the same as starboard engine. No noticeable leakage of oil or coolant.
We have run sea trials at 1200 rpm and 1560 rpm (chosen arbitrarily). At the lower rpm, temperature is good. At higher rpm, the reading goes to 210 F.
I need to get this problem solved as soon as possible. Any suggestions would be greatly appreciated.
Jeff Neville [email protected]"
 
"Hi there Jeff, I have a simil

"Hi there Jeff, I have a similar product with my Grand Banks 36 Classic, I have 2 Ford Lehman 185 Turbos, the Starboard engine developed a problem with over heating at around 1800 rpm, I stripped out the intake hose and cleaned the water intake bowls, replaced the intake hose and fitted a new Jabsco pump and drive, took off the water/water heat exchanger and cleaned out the tube stack and de scaled the water jacket,took off Turbo elbow and cleaned and pressure checked water injection into exhaust pipe, re assembled all and fitted new thermostat assy and filled with 60/40 Ethyl Glycol, fired up and ran engine, still over heated !!!!!! Have made several calls to many engineers and have come up with a solution !! Most people have stated that 65% of the engine cooling is done thru the oil !! I have not taken oil coolers off yet, instead I have ordered new oil coolers and transmission coolers ! Also have ordered a conditioner and additive for the coolant water and also a conditioner for the engine oil which helps oil temperature and cooling also ptotects dry starting ! I have flushed my engine blocks with different mixtures of water and anti freeze ! I will keep you posted, reading your posting was like I had written it ! Same problems ! It is most important to remove oil coolers and check them, the Lehman service on Bomacmarine.com suggests changing them every 2 years and 5 years for main heat exchangers ! My Engines are 1989 and done 1400 hours ! just run in !"
 
"I guess I will join the club

"I guess I will join the club with an overheating Lehman 120. If we run the engine above 1700rpm it gets hot. I have done all of the things that you have tried and still have the problem. I have checked the thru-hull, changed raw water pump, changed both the oil and transmission coolers, inspected and cleaned the main heat-exchanger (American Diesel thought there may be impeller parts from a failed raw water pump), flushed and cleaned the engine block, replaced the engine water pump and the expansion tank cap, and replaced all hoses. All of this has been to no avail. If you guys have come up with a solution please let me know. My next steps are to check corrosion in the manifold elbow and to bleed the main exhaust manifold. American Diesel indicates that air locks in the manifold are common if engine coolant has been changed or water pumps changed. These air locks cause chronic overheating problems. If anyone else has any suggestions please respond. The boat, a Marine Trader 36 with a single Lehman 120 has been in the great lakes its whole life and has never had to deal with salt water problems.

If I can't fix this thing the only solution will be drugs so I don't nuck the thing."
 
"Hi there Steve ! My name is M

"Hi there Steve ! My name is Mark Forrest and I am the proud owner of the Grand Banks with twin Lehman SP 185 Turbos with 1400 hours use on them, I have just had my water pumps overhauled and have just re fitted them, I am about to receive my new heat exchangers from British Columbia ! I am changing every one and then conditioning my oil and water ! I have had the header tanks off and cleaned, replaced the vent pipes off the manifold and turbo and increased the size. Had the raw water pumps replaced also and new intake pipe work ! I will keep you posted as soon as we fit the new heat exchangers, I will get to the bottom of this problem !"
 
"Hi Mark, between the two of u

"Hi Mark, between the two of us we might be able to figure this thing out. I am returning to the boat in two weeks and will attempt bleeding the manifold as American Diesel suggests. If that works I will let you know."
 
"Both overheat problems bring

"Both overheat problems bring up more questions. Has the overheat always been there or just come on? If your propellers are too big, the engines won't reach 2500 rpm and will run hot under higher loads. Did you check your thru hull pickup for obstruction or is the speed scoop missing? Is the intake water hose wire re-inforced? How about a semi collapsed engine oil cooling line? How about a collapsed exhaust hose or lift muffler problem causing excess back pressure? Have you checked the inj. pump timing?"
 
"I have now replaced all the h

"I have now replaced all the heat exchangers on both of my 185 Lehman turbos and added a Lucas oil conditioner and a Forte water conditioner to eliminate any small problems from coolants and oils ! Went to sea and my Port engine which has a chlorifier fitted for the hot water system, staid at a steady 80`centigrade even up to 2000 rpm, where the Starboard engine ran fine up until 1600 rpm when the temperature rose to 90`c and higher, throttle back and let engine come back to normal with no load ! The engine sounds sweet and smooth and comes back down to working temp and will run at 1500rpm all day ! It looks like the amount of sea water coolant on the Starboard engine is less than the Port ! This is my next option, Jabsco strip and clean and check delivery pipe from outlet to inlet on main water to water heat exchanger, have replaced water intake and checked exhaust pipe ! Getting very frustrated, what am I overlooking ? Help any body ? e mail me , please !"
 
"Have '78 34' Puget T

"Have '78 34' Puget Trawler with Ford Lehman. Have owned about 10 years with no significant problem. Would never run for long at 2500 without overheating, but figured was normal. This year have incurred progressive overheat problem. Used to run all day at 2200, am now down to 1850. Changed raw water impeller with no positive result. Am also looking for solution so guess I'll keep watching this string."
 
"THe Saga continues with my Fo

"THe Saga continues with my Ford Lehman 185 turbo with overheat problem, I have replaced and serviced and flushed and now I have possibly found the cause !! Last year when my overheat problem occured, I changed the Jabso pump which I have found out yesterday was a 3/4" with an output of 40 litres at 1500 rpm , wrong size my local Jabsco agent tells me, should be a 1" with 80 litre out put, this makes sense for when I run at 1500 rpm, engine will run all day long, only when I increase revs will temperature increase and over heat! This make sense if you are only getting half the capacity of the intercooler ? Let you all know after tommorrow, new 1" pump on way ?? Please bear in mind that I have replaced all oil and water inter coolers and serviced fresh water circulating pumps, I feel that this is a secondary problem and I am convinced that I would of had to change all inter coolers as a matter of preventitive maintenance and also that the engines are 17 years old !! Fingers crossed."
 
"I see by the posts that Mark

"I see by the posts that Mark had a 2C48 instead of a 2C49 pump on his turbo engine - big difference. Dennis may want to rebuild his water pump complete or replace with new. Just changing an impeller does not always help enough - there is the wear plate, cam, and endcover that all wears out. When these parts are worn, the clearance around the impeller is opened up and the pump will not deliver the needed water flow even with a new impeller. Also, pull the water hose off the pump side of the engine oil cooler and make sure some old impeller blades and debree are not blocking flow. Has Dennis replaced or cleaned any of the exchangers, checked exhaust elbow, thermostat, etc. Mike"
 
"I'm just starting the pro

"I'm just starting the process so only the impeller has been changed. I did that while anchored far out in Prince William sound. Visual inspection didn't seem to show excessive wear on the other pump parts.

Boat is docked 360 miles from home so I don't get to spend as much time with it as I'd like. I was thinking my next step might be to inspect the exhaust elbow, as I've had problems with those plugging up on gas engines in the past."
 
"My over heating Lehman 185 tu

"My over heating Lehman 185 turbo is now cured ! Having spent a lot of money and time, I have found the problem ! During my process of elimination I found after fitting my new 80 litre Jabsco pump, there was no difference to water flow !! So I started from scratch, isolate sea cock and dismantle my Grocco sea water filter and check flow from sea,which was o.k and then re assemble and remove 1" suction hose from sea cock to Jabsco and turn sea cock on to find a dribble !!!!! yep a dribble, there was a earth connection from bilge pump to nut on elbow outlet and some electrolytic reaction had caused a large build up of a resin like substance and reduced flow by 85%, I have now got superb flow and engine temperature is much lower, sea trial this next couple of days, I suggest any one with Grocco sea cocks to strip off outlet elbows and check !! New Jabsco much better flow !"
 
"We have just made it back fro

"We have just made it back from Lake Superior and our Lehman is still overheating. We bled the manifold to make sure no air was trapped.In addition we have now done what everyone else has. We did notice that as the engine got hot the engine hoses we starting to collapse. We removed them and placed stronger springs in them. It stopped the collapse but it still overheated. This means to me that there must be an obstruction somewhere in the engine cooling system We have descaled it once but will do so again. American Diesel assures me that you can run a Lehman all day wide open and it shouldn't over heat. They think there may be some impeller parts in the intake side of the raw water pump. This is a common problem and as the rpm of the engine increases the pump picks up these parts and plugs the intake. They also indicated that one should not mix anti-freeze and water more than 50/50 to do so reduces the cooling capacity. They indicate nothing cools better than water; additives are a hype. Since the season is almost over in the Great Lakes, we will try next season. Frustrated in Wisc."
 
"Hello Steve. You can certain

"Hello Steve. You can certainly check fairly easily to see if there are any impeller parts on the intake side of the raw water pump by just shutting off the seacock, removing the hose at the intake side of the pump and opening the sea cock to let water flow through. Catch the water in a bucket to see if any impeller pieces are there.
I'm still working on my problem and have reason to think at least part of the problem is with the wiring to the temperature gauge. I was getting readings as high as 215 deg. and the alarm did not go off nor were there any indications such as the engine steaming etc. Not sure if you 've approached this possibility. I've done some work on the wiring and now get readings of 195 to 200. Still too much over the 185 recommended temperature so I'm still working on things."
 
Hi Jeff: That will be my next

Hi Jeff: That will be my next step. I have replaced the raw water pump but did not take the hose off and turn the thing upside down to see if impeller parts were in it. I am also going to install a larger through hull and increase hose size while I am at it.I will be going back up in Oct. to take the boat out for the season. So that will be a good time to do it. Wish me luck
Steve
 
"Change out fuel filters, lack

"Change out fuel filters, lack of full flow diesel oil will cause engine to overheat. SOme of the diesel oil by passes the injector's and is used for cooling. If filter are clogged not enough flow, over heats at higher rpm."
 
"I thing you should try a citr

"I thing you should try a citric flush of the cooling system. This will remove years of build up of anti-freeze, scales, and the like which will lower the transfer of heat. Here how it is done in a car. Bill
thumbs_up.gif

http://www.idahobombersforum.com/tips/general/coolingsystemflush.htm"
 
"Hi there, I finally have been

"Hi there, I finally have been for a sea trial and covered approxiamately 30 sea miles at 1950 rpm and both engines are now perfect, no steam from Starboard engine and both running around 80`centigrade, this is awesome now that I can rely on both engines again, having 2 x 185 turbos and not having the confidence when you need it spoils the whole boats purpose and capability ! A very happy Lehman owner. Mark"
 
"Spring has returned to the fa

"Spring has returned to the far north and I have just returned from our first trip to the boat. Found my overheating problem. Someone above mentioned the inlet elbow for the strainer. Sure enough, after removing the inlet hose, I found a stem about 3 inches long lodged in the elbow with leaf portions. Removed and water flow back to normal as is temperature. Of course I only found his after back flowing the entire raw water system, etc."
 
"Hi Wayne, try following my el

"Hi Wayne, try following my elimination procedure and start from water intake and elbow, thru to hoses and end caps off heat exchangers and injection elbow on exhaust, any problems e mail me at [email protected]"
 
"Greetings, Congrats Mark,grea

"Greetings, Congrats Mark,great bit of troubleshooting,finally! The bits about AIR Pockets is also muy importante! I hope all the others in this thread get such positive results.Nice catch on the Earthing wire prob.
Thanks, been an interesting thread!"
 
"I am new to this forum with a

"I am new to this forum with a 1974 CHB with Ford Lehman 120 that is overheating. I have read all of the above postings and have verified flow through strainer, replaced impeller, thermostat, have checked that heat exchanger tubes are clear, and have checked all seawater hoses.

Curiously, I tried removing the thermostat and the engine did not overheat! I thought I had a bad thermostat and bought a new one that matched the old one (Carquest 54MM 160 degrees, PN 60206). After the successful run last week, I had thought that my problem was solved, but when I installed the new thermostat today, the engine overheated above 1600 RPM. Without the thermostat it ran 195 degrees for almost an hour at 2200 RPM. Is it possible my thermostat is simply not allowing enough flow when open? Is it OK to run without a thermostat? Maybe I should call American Diesel and get the right thermostat? My Lehman manual says absolutely nothing about the thermostat other than it exists.

I've had the boat 2 years and regrettably neglected it for the 1st year. Making amends now. When I got the boat it ran about 205 degrees at 2000 RPM -- which I now realize is above spec. But it didn't overheat. My overheating problems all started after having some work done on my transmission.

Now that I have found this forum I see I'm in good company with this problem. I love the old boat and look forward the getting my Lehman happy again.

Mark.

P.S. Is "bleeding" the manifold as simple as the manual suggests by opening the valve at the top forward end of the manifold until coolant streams out? My manual blames air pockets in the system for most overheating problems."
 
"You need to check the end pla

"You need to check the end plate and wear plate in the water pump for excess wear. The usual problem with the heat exchangers is that on the fresh water side the tubes get a build up of rust and they will not transfer heat properly. When you have the heat exchangers cleaned they cannot remove the rust from the fresh water circuit. You should fix your problem by replacing the heat exchanger and check water pump. Give me a call if I can help you further.

Greg
www.bomacmarine.com
1-866-419-6363"
 
"i have just purchased a 1977

"i have just purchased a 1977 marine trader trawler with a 120 hp lehman and was going across the bay running at 1500 rpm everything seemed to be ok temp guage was at 185 and oil pressure was great, just as i entered the marina the engine stalled and i opened the hatch to find steam and heat, i added water alot of water and restarted the motor and now i have what i call a tick but some may say a knock, motor runs great but now with the ticking noise, can anybody tell me what i could have damaged when i got it this hot."
 
"You overheated the engine and

"You overheated the engine and seized a piston when it got hot and that is what's knocking. The overheat could have been caused by water restriction in your exhaust, an old heat exchanger..............something in your cooling system failed. You will have to have the engine remanufactured. If I can help you further please call me on my cell as I am not in the office 954-325-5321. Greg Lilienthal
www.bomacmarine.com"
 
"Hello Robert, We just had thi

"Hello Robert, We just had this problem here in our Marina, and the issue turned out to be an internally cracked Exhaust Manifold,leaking combustion out and antifreeze in, Bingo! overheat and then water in cylinders. good luck,Greg can probably help you out."
 
"Great site. Am experiencing o

"Great site. Am experiencing overheating on port 254CI Lehman engine on 1977 Kadey Krogen. I have done/checked most of above suggestions. I need to know just how the exhaust riser works before I take it apart.I will check hoses, and intake elbow. Thanks for input -- Alex"
 
Lehman rear crankshaft seals..

Lehman rear crankshaft seals... 1989 2725TI.. hi in the middle of overhaul and the new cord type rear seals (altho supplier says roll in) have been prone to leaking according to my engineers previous experiences with them.. they are different from the ones we have taken out... any one had this problem and know an alternative supplier that we can try.. cheers peter
 
Back
Top