Running Hot(er)

[Rip]

The 1505 engine in my F-3680 (3000 hrs) running hotter than it used to with new t-stat, cap, clean rad, coolant, oil & fuel filters, etc. Not really 'over heating' as such, but concerned. Runs well with good power but wondering about injector timing/spray pattern (have no experience with injectors)? Wondering if any had similar experience with this engine & problem?
Have another 1105 engine in similar machine (2000 hrs) and at idle it shows about 30 deg F cooler block and rad tank (per infrared temp gun) than the 1505 under same conditions. Dash temp gauge also about 30% vs 45% on the 1505 engine at warm idle.
Cheers, Rip

 

[RBsingl]

I have seen water pump impellers in other applications losing effectiveness due to wear with higher operating hours. Water pumps don't just fail because of seal or bearing issues, the impeller can also wear with age resulting in less circulation.

It is also worth checking the hoses. It isn't common but the interior can delaminate reducing flow rate.

Rodger

 

[Rip]

Water pump looks to have been replaced once on this (second-third hand) used machine, so probably not as old as rest. Top hose looked fine when I replaced the t-stat and cap, and no indications of corrosion or sludge when flushed and replaced coolant.... but have not had radiator internally cleaned.... exterior fins and all quite clean.

I know ignition timing or lean mixture on gas engines can make them run hot, so figure could happen to diesel as well.... just have no experience with that side of them.

 

[Dman1981]

Yes if a diesel is running lean can cause some overheating

 

[Rip]

Is what I thought.... may find someone with more diesel experience to look over my shoulder if I pull them.... there is a local injector shop that can test them. May do bit more radiator check and clean first though.

 

[Russian]

I just fought all of the similar issues on an F3060. Have you changed your pump/alt v-belt?

 

[Rip]

Belt is tight and in good condition (is also a real pain to change!)

 

[RBsingl]

Diesels don't run lean in the sense the term is used for spark ignition gas engines, they aren't like gas engines where a lean mixture results in hotter combustion. At a "lean" mixture, diesel engines run extremely cool.

At idle and at very low load, a diesel is typically operating in the range of 60:1 air to fuel ratio. This results in very cool combustion compared to the around 18:1 it drops to under high load. Too much fuel in a diesel is what increases combustion temperature, excessive EGT, and high soot output from incomplete combustion.

A diesel engine doesn't have a throttle plate (with the exception of some of the new Tier IV complaint where intake air is restricted during DPF regeneration to build more heat), isn't held within a narrow range of fuel/air mixture like a gas engine, and with less fuel injected it will generate less combustion heat.

At idle and with low operating load a diesel engine runs an extremely low fuel to air ratio, that ratio increases rapidly under heavy load. Diesel engine EGT goes up rapidly with very high fuel to air ratio.

Rodger

 

[Rip]

Thanks for the diesel details Rodger.... I knew was not same as for a gas engine, but the service manual does mention injector timing as potential issue for overheating. I guess individual injector problem would be more of a power issue (not in my case). After giving the cooling system bit more of a lookover, may still have to get a more diesel savvy person to take a look.

 

[CalG]

The question is oil temperature.

Above about 229 degrees F oil starts calling it a daay.

Anything below about 205 is good

 

[RBsingl]

Thanks for the diesel details Rodger.... I knew was not same as for a gas engine, but the service manual does mention injector timing as potential issue for overheating. I guess individual injector problem would be more of a power issue (not in my case). After giving the cooling system bit more of a lookover, may still have to get a more diesel savvy person to take a look.

 

[RBsingl]

Rip,

Over fueling (leaky injector, poor spray pattern) will cause the engine to run hotter but normally with that you will see a lot of smoke and also have poor running. Late injection will also increase heat but that is a pump timing issue that generally results from incorrect adjustment and doesn't just happen in operation. You would also notice smoke and a drop in power with this issue.

But basically a diesel engine is like a campfire You have plenty of air and the only way to make more heat is to throw more logs on the fire. A lot of air and a little fuel with a diesel results in cooler combustion.

The cooling system would be my prime suspect (thermostat may not be fully opening, restriction in radiator tubes to buildup, water pump not delivering full flow, hose delamination, etc.)

Rodger

 

[Rip]

Thanks again Rodger.... no smoke or power loss, so will concentrate on cooling system some more. Cheers, Rip

 

[5030]

Old post but I'm wondering if the radiator is clean and free of obstructions like dry grass? On my farm use Kubota's, I have to blow out the radiators at least once per day and sometimes more often, depending on the amount of debris floating in the air.

 

[Rip]

Yes, I learned early on to keep close eye on the rad screen and blow it and the rad itself clear often especially in dry conditions. Did a full cooling system 'flush' while back, but looked good before and after.
Also rigged up a rubber flap discharge chute to divert the grass further from the machine and thus less likely to get sucked back into the engine bay. The F-3680 still seems to run bit hotter than the 2880, but still in a 'normal' range and no other symptoms lately.
Grass pretty dormant last couple months but will get going again in another 6 weeks or so. Will keep close eye on everything.

Cheers, Rip

 

[5030]

I'm converting my big Kubota M9's from mechanical drive fans to electric push pull fans and removing the mechanical fans entirely and will most likely do that to the F series when I get it this spring as well. My only maybe issue will be alternator output as a large push-pull electric fan does consume some amperage. On the plus side, removing the mechanical fan removes the parasitic horsepower loss as well. I'm doing it primarily to eliminate the chaff buildup when I run hay and having to stop and blow out the rad often. With an electrically reversable fan, I can reverse the fan to push the air instead of suck it in and that will purge the chaff and stuff out of the radiator and in the case of my M's, the air to air charge air coolers and the hydraulic oil coolers as well.

I'll still clean them here at the farm with a Radiator Genie but I will eliminate most of the cleaning I now have to do and not have to carry my cordless blower behind the seat all the time as well. Kubota's (at least mine) are sensitive to clogged or even partially obstructed radiators and I'm always watching the temperature gage, especially during hot weather because it has a bad habit of creeping up un noticed.

I figure I'll pick up at least 5 horsepower removing the mechanical fan on my tractors.

Automakers figured that out some years ago and why vehicles today mostly come with electric radiator fans, especially with the smaller engines.

I'm going to size the fans to the shroud opening and bracket them to it and I'll install a manual reversing switch on the dash so I can control the direction or disable it entirely as the situation presents itself.

 

[Rip]

Sounds interesting.... may help the clogging situation if reverse-flow ONLY done briefly where dust/chaff can not be pulled into the open (and unscreened) engine bay.

My air filters tend to choke up under same conditions that clog the rad screens, so I pull them and knock/blow dust from them every day routinely. The 1505 engine has a flow restriction warning devise on the intake, but the 1105 does not.... but still can only see it with engine cover open.

 

[Richard001]

I'm converting my big Kubota M9's from mechanical drive fans to electric push pull fans and removing the mechanical fans entirely and will most likely do that to the F series when I get it this spring as well. My only maybe issue will be alternator output as a large push-pull electric fan does consume some amperage. On the plus side, removing the mechanical fan removes the parasitic horsepower loss as well. I'm doing it primarily to eliminate the chaff buildup when I run hay and having to stop and blow out the rad often. With an electrically reversable fan, I can reverse the fan to push the air instead of suck it in and that will purge the chaff and stuff out of the radiator and in the case of my M's, the air to air charge air coolers and the hydraulic oil coolers as well.

I'll still clean them here at the farm with a Radiator Genie but I will eliminate most of the cleaning I now have to do and not have to carry my cordless blower behind the seat all the time as well. Kubota's (at least mine) are sensitive to clogged or even partially obstructed radiators and I'm always watching the temperature gage, especially during hot weather because it has a bad habit of creeping up un noticed.

I figure I'll pick up at least 5 horsepower removing the mechanical fan on my tractors.

Automakers figured that out some years ago and why vehicles today mostly come with electric radiator fans, especially with the smaller engines.

I'm going to size the fans to the shroud opening and bracket them to it and I'll install a manual reversing switch on the dash so I can control the direction or disable it entirely as the situation presents itself.

I don't know where you are getting your fans, but if they are automotive type fans, keep in mind that while they are indeed DC voltage motors, every automotive fan I have encountered has a diode in it that is intended to shunt voltage feedback to the controlling relay to prevent arcing of the relay contacts.

You may want to be sure that the fans that you get do NOT have this diode in it.

Richard

 

[5030]

Not using a relay at all. Using a 3 position latching toggle switch reverse, off, forward. Or in my case suck or blow...