490E Overheating & Electric fans

The OAT here is 110, and working in direct sun makes the machine metal about 125 F. In discussions with the dealer most everyone in our area is having problems with machine heat. I have been through this machine toward lowering the heat load. Stall it hot, and restarting is a problem.

I am considering installing thermostatically controlled electric fans in front of the hydraulic cooler and radiator to increase air flow through the system toward improving cooling. Has anyone on this site done that? Were the results worth the effort?

Most of these have constant drive fans already in service, do not think will gain anything of significant value in this.

Have you checked and eliminated other causes?

1. Fan belt condition?
2. Thermostats?
3. Blockage of the radiator or oil cooler fins?
4. Any loss of coolant?
5. Fan blade condition?
6. Water pump circulation?
7. The temperature at the engine outlet versus the temperature going in?
8. Air bubbles in the coolant?
9. Excessive fueling/loading of the engine?
10. Fan shroud condition?

A lot of things can cause an engine to overheat.

Other thing is make sure ALL the foam insulation is in good shape around the hood radiator and oil cooler.

i considered moving the muffler out of the engine compartment (mississippi)

dirthog said:

Other thing is make sure ALL the foam insulation is in good shape around the hood radiator and oil cooler.

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Probably the number 1 problem with older machines.

Works for me I installed a set with a toggle switch, I just run them full time when it's hot. I have the thermostat control to install, but I temporarily installed it as an experiment, don't think it's worth adding now. I know my machine shouldn't need the additional cooling, but after all the troubleshooting and not finding anything specific to fix, it keeps it from overheating. Mine is an old machine, I'd rather help it out with a fan than cook the engine and hydraulic pumps.

Thanks for all the replies. A cooler machine is obviously a longer lasting machine. Yes, I have been through everything on this machine. Had the radiator boiled and rodded, thermostat, seals between the hydraulic cooler, radiator and fan shroud, replaced the fan belt, resealed everything. Both the radiator and hydraulic cooler are clean. Searched through all the hydraulics for a heat source, none found. The machine could not be run on P for longer than 1 hour without causing a heat warning horn, so I have been running it on E. Even then it operated near red line and any stall was a restart problem.

I installed a 3,000 CFM, 16 inch low profile pusher fan, centered in front of the radiator, thermostatically controlled, set at 160F to come on, with a manual switch to turn the system off. The results were well worth the effort (and cost, materials about $300). It now runs on P with the temp gauge where it should be, about 1/4 inch off of red. This being a 24V machine, I installed a 40 A transformer to make the 18 A 12 V needed for the control system and fan, switch is installed on the hot leg to the transformer, with a 30 A fuse in the fan hot wire. The fan does make a little noise, but in my opinion, I will tolerate it for the cooler machine and more reliable operation. Heat is lost energy, so I am moving from my heat gun (which could not find the source) to an infrared camera in further search for the source.

In my own deranged opinion ,pumps and motors wear over the working life of the machine increasing back leakage generating more heat as they wear . You may be looking for a problem that isnot there or a viable to repair .
Sounds like you are sorted already if your alternator is up to the job .
Are your fan belt pulleys in reasonable condition ?
Are the panels restricting the airflow ? The man that designed them might have spared the holes .
I would expect the machine to run cooler (with a direct drive fan) at full rpm than economy mode unless there is an air flow issue .
Why the hard restart when hot ?
Why does it stall ?

I would be looking at pressures. It sounds as though your pump may be held partially stroked. Which would also contribute to stalling and subsequent hard start. Additionally look in the oil flow diagram to and from your cooler. Should be a thermostat and bypass valve, maybe. Have seen the thermostat fail if not properly assembled. Just an FYI of things to consider.
Now Volvomad brings up a real strong possibility. Your fan pump or motor may be weak. Have you checked speed against desired speed? Did someone unplug the tank temp sensor to ramp the fan up. Guys will do that and it shortens the life of the motor, significantly.
Good luck
BTW does the engine run hot or just the hydraulics?

Good day
Many manufactures offer tropical fans and coolers as options for extreme climates, may be its missing from JD but it may be worth a little research on a similar Hitachi.
Kind regards
Uffex

funwithfuel said:

Should be a thermostat and bypass valve, maybe

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I would look at your bypass as FWF said. It is inline in the return line that goes from your control valve directly to the tank, not in the line that goes from the control valve to the cooler. You might be overheating because your hydraulics are getting hot and since the hyd oil cooler is mounted on the outside of the radiator with a sucker fan you could be drawing hotter than usual air across your radiator. Again as FWF stated pressure checks are in order to see what the machine is doing or not supposed to be doing. Also might want to check your angle sensor, DP sensor and pump delivery pressure sensor, to make sure the hydraulics aren't partially loaded at idle or causing excessive pulldown under load. Any one of these sensors can cause hydraulic issues that can cause overheating. As stated by others eliminate basics first....coolant condition, plugging of cooler/rad, shrouding, belt, fan installed correctly, etc. If you don't have a manual, you will need one (TM1504).

funwithfuel said:

Your fan pump or motor may be weak

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FYI FWF. That machine has a direct drive fan via a belt.

On older machines the relief valve springs weaken causing the hydraulics to heat up which causes the engine to overheat. I proved this point many years ago on a Cat 330 with unknown hours.

Try some off the wall stuff
1) engine timeing
2) injectors not atomizing fuel enough
3) compression
4) exhaust restriction

Thanks to all for your replies and suggestions. I have checked them all. This being a 20+ year old machine previously used by a pipeline company with 7,000 hours and 38 inch bucket digging in tough sand clay, it may well be an accumulation of wear. It has no problem loading the bucket to the tilting point of the machine. I have essentially been through this machine searching for the cause of the heat problem. I had the injector pump overhauled, injectors checked and have been through the entire cooling system. I replaced the angle sensor, DP sensor, removed the pump for inspection at the hydraulics shop with no concerns found. The sensors were bad because when I bought this machine, the computer was fried. The fried computer was because someone replaced the 1 amp fuse with a 5. The true fault with the computer was a fault to ground found in the main power wire to the computer in the harness. The hydraulic pump dampener was toast and was replaced. I have check for leakage in the swing motor, checked and adjusted all operating pressures. I have replaced the turbo and the exhaust system. I believe the heat is coming from the hydraulic system. This machine, as a first generation computer controlled machine, is loaded with pressure control valves everywhere. The 3,000 CFM electric pusher fan has reduced the heat load on the machine to what I consider normal, so now it can work reliably. Some suggested I sell the machine and get another one. I am stubborn enough to not allow a machine beat me.