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Ford Lehman overheat

"Larry,
Try American Diesel

"Larry,
Try American Diesel in Virginia. (804)435-8107. They rebuild Ford Lehman's and are very knowledgeable.
Jeff Neville"
 
"Very interesting how you figu

"Very interesting how you figured out some comon problems.
I noticed that no one is talking about another possible culprit in the overheating saga.
As pointed out buy others, diesel egnines rely on oil to dissipate heat from the bottom of pistons and heads more than petrol engines.

Diesel build up a lot of muck and flushing out the sludge from sump, conduits, heat exchangers, pistons an anywhere else, with an appropriate flush product is very important. There are flush product that rely on solvents and others that rely on detergents. The detergent seem to work better but anything is better than nothing.

The proper procedure is to drain all old oil first leaving old filter in, replace with the cheapest no frill oil you can find, and run the engine a bit more than idle with the flush product in the cheap new oil for the time recomended by the manufacturer. Drain again and replace with good new oil and filter.

The sludge build up is an insulator and does not allow the oil to cool down the pistons and heads. Don't be surprised if you will now need one or two extra litres of oil.
www.costeffective.com.au
This website talks a lot about the effects of flushing out sludge. They of course want to sell their product, yet it is informative nontheless. I am sure you know other comparative products that sell in the US."
 
"Marc,
Thanks very much f

"Marc,
Thanks very much for your input. I'll give it a try when I put my boat in the water in early May. My overheat has diminished, but still registers high on the gauge. The engine temperature does not exceed the limit so it does not sound the alarm or shut off. However,I do want to get it completely normal
Jeff"
 
"Marc,
Re your post on March

"Marc,
Re your post on March 16,2009 about flushing out sludge for cooling.

I am interested in the "comparative products sold in the US". I emailed costeffective and their postage cost is around $400 because of hazardous material charges.

Also interested if anyone has personal experience with helping glazed cylinder walls and what product was used.

Bill"
 
"Mate, just do a Google search

"Mate, just do a Google search.
You have Lubegard, Forte, Amsoil, Valvoline. This are the fast solvent based that will do the initial clean up and free the most sludge. 1/2 hour idling and out goes all the dirt.

However you also have a detergent based product that works different and is added to the oil and cleans slowly as you use your engine in the normal way.
http://auto-rx.com/index.html
I don't have any experience with either of the products mentioned, since I use Nulon before each oil change over and CEM once a year for a deep clean. Both products are Australian and postage could only be done surface mail due to them being flamable.
Auto-rx seems to have a lot of info and proably worth while having a chat with them.
And I am sure you have also heaps of other and better products too."
 
I need to replace the fill cap

I need to replace the fill cap for my fresh water
expansion tank. Is this a standard auto radiator
cap or a special"marine cap"?
Thanks
 
"Joe,
I can't give you a

"Joe,
I can't give you a positive answer to your cap question one way or another, but I do know that there are several caps which differ as to the temperature or pressure at which they allow overflow. I recommend you talk to American Diesel in Virginia (804) 435-3107 and see what they say. They may tell you to buy a specific cap from them, but they will explain why and you can decide whether to follow their advice. They are very knowledgeable and have always been helpful."
 
"Hi. I have Ford Lehman turbo

"Hi. I have Ford Lehman turbo deisel in marine, so i need help, i`m looking a plans of cooling systems and el-systems. evrything varking jast need conection but i do not know haw. plese help me"
 
Re: "I have a 1979 Grand Banks 36

jeffneville said:
"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]"
Click to expand...
I too have a 1979 36' Grand Banks with twin Lehmans, engine water pump impeller maybe slipping on the shaft at higher RPMs. May need to change engine water pump. Have seen this several times on cats and cummins engines!
 
I see this is an older thread but contains a lot of useful info. I have a current temperature problem with my SP90 (single engine in a Nauticat)... gently grounded on a sandbar last week (Bahamas) and eventually floated off on the tide. The next day noted that the T gauge - usually at 185/190 F was just over 200. Sailed back to marina and have done all the below but still see 205 or so at idle (before I shut down) within 15 minutes of starting.

Cleaned strainer (a wee bit of sand and 3 blades of grass)
Replaced impeller (old one looked perfect)
Removed water hose at exhaust elbow and felt around for obstructions with finger -- negative)
Opened primary heat exchanger ends for inspection - a bit scaly but found no debris.
Topped up fresh water system (maybe added a cup).
Back flushed all segmensts of seawater system with marina hose (including all three heat exchangers).

Problem persists. Today plan to:

Tighten alternator belt (which I believe drives the fresh water pump)
Find a way to examine the seawater intake outside the through hull (a kind of sharky marina)
Find the fresh water purge (forward on the exhaust manifold?)
Call American Diesel (love those guys!)

If none of that works plan to replace thermostat and remove and hand de-scale the primary heat exchanger.

Anybody have any other ideas?
 
demerittj said:
I see this is an older thread but contains a lot of useful info. I have a current temperature problem with my SP90 (single engine in a Nauticat)... gently grounded on a sandbar last week (Bahamas) and eventually floated off on the tide. The next day noted that the T gauge - usually at 185/190 F was just over 200. Sailed back to marina and have done all the below but still see 205 or so at idle (before I shut down) within 15 minutes of starting.

Cleaned strainer (a wee bit of sand and 3 blades of grass)
Replaced impeller (old one looked perfect)
Removed water hose at exhaust elbow and felt around for obstructions with finger -- negative)
Opened primary heat exchanger ends for inspection - a bit scaly but found no debris.
Topped up fresh water system (maybe added a cup).
Back flushed all segmensts of seawater system with marina hose (including all three heat exchangers).

Problem persists. Today plan to:

Tighten alternator belt (which I believe drives the fresh water pump)
Find a way to examine the seawater intake outside the through hull (a kind of sharky marina)
Find the fresh water purge (forward on the exhaust manifold?)
Call American Diesel (love those guys!)

If none of that works plan to replace thermostat and remove and hand de-scale the primary heat exchanger.

Anybody have any other ideas?
Click to expand...

What exactly was your process of back flushing the heat exchanger? just curious
I would say if you haven't been able to confirm any blockage at the throughull, that would be my first stop. If you're certain the heat exchanger is free of obstruction my second stop would the thermostat and the oil cooler.
 
Hi, thanks for your interest...

To backflush I disconnected hoses at multiple points and forced fresh water through the system in the direction against normal flow. Then checked the input end of the heat exchangers for obstruction. Today I also rodded out the main heat exchanger (or as much as i could reach while leaving it in place and examined the seawater intake with an underwater camera (nothing visible from outside the small grate over the intake). Ran 15 minutes at idle and watched Temperature gauge (is it the real T?) climb to 215 F.... Then I turned up the throttle and watched it apparently fall back to 195 F (still hot but acceptable).....

Tomorrow I will attach a thermocouple near the T sensor on the engine to verify or refute gauge at helm.

American Diesel (Brian) says it is probably the gauge itself. I am not so sure.

Jeff D.
 
Last edited:
demerittj said:
Hi, thanks for your interest...

To backflush I disconnected hoses at multiple points and forced fresh water through the system in the direction against normal flow. Then checked the input end of the heat exchangers for obstruction. Today I also rodded out the main heat exchanger (or as much as i could reach while leaving it in place and examined the seawater intake with an underwater camera (nothing visible from outside the small grate over the intake). Ran 15 minutes at idle and watched Temperature gauge (is it the real T?) climb to 215 F.... Then I turned up the throttle and watched it apparently fall back to 195 F (still hot but acceptable).....

Tomorrow I will attach a thermocouple near the T sensor on the engine to verify or refute gauge at helm.

American Diesel (Brian) says it is probably the gauge itself. I am not so sure.

Jeff D.
Click to expand...

I saw your post on cruisersforum, some decent ideas like checking the hoses in that thread. Is it pumping good out the exhaust when running? If you can, confirm temperature with an IR gun, always helpful to have on hand. I saw in another thread a mention of pressure testing the heat exchanger, may be an internal leak diluting your coolant, could also check the specific gravity of the coolant, just another cheap option. I still think the thermostat is worth a change and oil cooler blockage worth a look if that doesn't resolve it. I'm not entirely familiar with the naturally aspirated 4 cylinder normal operating temps, 195-200 is normal for for some diesels but obviously hot for yours.
The other idea I saw was the bearings in the water pump itself.. Just a thought.
 
Hi Demerittj, Ibelieve you will find rust/scale blockage at the exhaust elbow. It's fairly common and since you say the temp drops with engine speed it indicates to me a blockage. unlikely the thermostat but possible! Remove the exhaust hose from the elbow and look inside the elbow water passage for rust blockage.
Charlie W
 
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