Motor running cold

[Phil23]

Hi team, after 10 years I have just learnt my temperature gauge is reading way out and I have been running a 4 cylinder Ford Lemann at 80 to 85 centigrade instead of the factory Ford spec of 99 deg.


What is the effect of running a diesel cold and will I have done any damage!!

 

[LaBomba]

Many Diesel engines run at 80 to 85 C so I wouldn't expect that you have done any harm whatsoever. Overheating is more detrimental IMO.

 

[Comodave]

85C converts to 185F, that is what my SP225s run at.

 

[Lou_tribal]

What temp are you measuring and what temp is recommended to be 99C? If measure is coolant and recommendation is oil temps this is normal.

L

 

[Nomad Willy]

My Mitsu runs very close to 200f.
On the original thermostat.
Can’t remember the cap release pressure. Guessing 13lbs.
I don’t see a problem w higher coolant temp other than if you encounter a problem (such as a coolant leak causing a temp rise) things could get out of hand alittle sooner. But the boiling point could be the same number of lbs pressure above the thermostat opening temp. So it’s not that different if at all. But with higher pressure the boiling point will be higher. Put another way one could run 5 to 7 degrees hotter w/o boiling. Very similar just higher pressure and temp. And again (for me) this was the thermostat that came w the engine new.

As to the downside to running cold (about 170f or less) the buildup of varnishes and other deposits in the ring lands and elsewhere that cause compression loss lowering combustion temps again increasing deposits ect ect. From a standpoint of varnish, sludge and other similar troubles running hotter is better ... IMO.

 

[RT Firefly]

Greetings,
Mr.23. My girlfriend's got the same problem....

 

[AusCan]

My Vetus (Mitsubishi) runs at about 85 Celsius. My old MD17 Volvo ran at about 60C but raw water cooled engines always run cool to minimise salt build up. It doesn’t harm the engine.

 

[Lepke]

Looks normal to me.

 

[IRENE]

FWIW, our John Deere 4045TFM75 (107hp M1) runs a 180-degree thermostat. The normal range we observe is 175-184, and we are keel-cooled.

 

[North Baltic sea]

Hi,

Your Ford engine and thermostat:

If you suspect this is not working properly, you can immerse it in a suitable container that will gradually warm up. Valve must start open at 71 ° C and 87 ° C full open.

Do not adjust if the thermostat does not function properly. Replace it with a new one

Are you sure that 99 ° C would be the correct heat of the oil and not the cooling because the oil max heat is given at 116 ° C?


Your engine run fine cooling temp, 80-85°C is very OK, i think.
NBs

 

[Wxx3]

Hi team, after 10 years I have just learnt my temperature gauge is reading way out and I have been running a 4 cylinder Ford Lemann at 80 to 85 centigrade instead of the factory Ford spec of 99 deg.


What is the effect of running a diesel cold and will I have done any damage!!

Well I must be toast, since my Ford Lehman run 77 to 83C routinely since forever.

It does not make sense that the coolant temperature is supposed to be 99C.
Ignore whatever you have read and carry on.

 

[kchace]

Standard FL thermostat temp is specd at 78c.

 

[North Baltic sea]

Standard FL thermostat temp is specd at 78c.

Hi,
This information Ford Lehman sabre, I do not know the difference between basic Lehman? Link to material.

page 9, optimal temperature 90°C, termostat operation temp 79-88 °C (175-190)


https://www.kdtrading.no/file/nedlastinger/deleboker/ford/ford_lehman.pdf

NBs

 

[Larry M]

Bomac Marine, when Greg, rebuilt our engine, installed a 75 C (167 F) thermostat. At first I though my electronic gauge was off. They use to read 187 F. I installed a mechanical gauge that confirmed my electrical gauge was good. I called Boamac and he said running a little cooler is better than running hotter on the FLs. The last oil analysis was perfect so I’m leaving it. I trust Bomac. They probably rebuild more FLs than anyone else in the country. For what it’s worth, we typically don’t run for less than 4 or 5 hours at a time and usually longer.

 

[jleonard]

My FL 120 runs at 170 F at the expansion tank with a standard thermostat.

 

[Phil23]

Thanks for all the advise guys I am sticking with my 80 degree C

 

[catalinajack]

My FL 120 runs at 170 F at the expansion tank with a standard thermostat.

What is a "standard" thermostat? At what temp does your standard thermostat begin to open?

 

[jleonard]

What is a "standard" thermostat? At what temp does your standard thermostat begin to open?

The one I got from ADC when I ordered a new one. No clue when it starts to open.

The reason I installed a new one was that I had all the coolant out because I was installing a new circulation pump. Figured I do the thermostat too.

The after temp was the same as the before temp.

 

[Nomad Willy]

jlenoard wrote;
"My FL 120 runs at 170 F at the expansion tank with a standard thermostat."

The coolant in the expansion tank is no doubt cooler than in the block. So you're probably running 185 or so in the water jackets and quite likely 195 in places. ... IMO

Isn't the them sensor usually right under the thermostat?

 

[jleonard]

Per ADC, I am right on the money at 170 there and it's via a mechanical gage that the PO installed (after he went to Bob Smith's class).

At the temp sensor I am at 180 F (on the lower station gage) and that's is verified with my temp gun. (flybridge gage reads about 5 degrees higher)

That's at cruise rpm which is around 1700. If I crank her up to WOT the lower station gage climbs to about 190 and holds there.

 

[Nomad Willy]

Sounds perfect Jay.

 

[koliver]

Hi team, after 10 years I have just learnt my temperature gauge is reading way out and I have been running a 4 cylinder Ford Lemann at 80 to 85 centigrade instead of the factory Ford spec of 99 deg.


What is the effect of running a diesel cold and will I have done any damage!!

If you have ten years of cold running with no ill effects, you have already answered your question.

I run at 185F. I get alarmed if I see 200F. You are suggesting 210, I would be quite alarmed.

 

[Nomad Willy]

I see 200f at times on my Mitsu and never had a problem of it being too hot.
But the gauge has not been checked for accuracy.

As far as I know the hotter the better if there is not problems. And w underloaded engines I’m sure hotter is better. But if you’re inclined to go hotter than specs say for the engine a higher pressure cap should be used .. only one or two lbs. Then one should replace hoses to HD. A weak or damaged head gasket could let go w more pressure but all of this is very unlikely if all is in good condition.

 

[BruceK]

... the factory Ford spec of 99 deg....

I wonder about this "spec". Where does it come from?