MX5100 running hot when bush hogging

[Jimmy2980]

My 2013 mx5100 hst has always ran at the very top of the temperature gauge while bush hogging. I have taken it to the local dealer and they could not find any reason for it. I had the injectors inspected and repaired, and I thought that may make a difference, but it didn’t. Changed the hydraulic fluid. Had the radiator flushed and inspected, no problem was found. Changed the thermostat, no difference. Replaced the water pump and belt, no improvement. Even bought a new $48.92 radiator cap, but no improvement. No valves are sticking, pump is not whining. With it always running hot when bush hogging, there is no forgiveness when seeds and chaff buildup. I feel like it’s something simple that I am missing. Any thoughts?

 

[EPIC]

Does it run hot doing anything else that doesn’t involve mowing?

What size/type of mower?

How close are you mowing and how thick is the grass?

tell us more details.

 

[JasonW]

My MX5100 temperature gauge has always been 1/4 when warmed up and will creep towards 1/2 and 3/4 when the radiator is starting to get blocked.

Get an infrared temp gun and check it with that. Measure the upper and lower radiator hoses, engine block etc. Without actual numbers it’s all guessing.

 

[Jim L.]

"With it always running hot when bush hogging, there is no forgiveness when seeds and chaff buildup."

When it is that season, about every 30, 45 minutes the radiator will need to be blown with air to clear the junk out.

I will also note that the temperature gauge does not have to be in the red for the head to crack. Each time that the temperature goes from ambient to not quite in the red, there is movement between the block, gasket, and head. That is the weak spot which leads to head cracks.

The radiator may need to be pulled out, outside soaked, and any foreign stuff dislodged from the radiator fins. I've found that a rectangular brazing rod fits well between the fins so as to not damage them.

Good luck with troubleshooting - not something to kick down the road.

 

[TheOldHokie]

Measure actual coolant temp with a quality gauge.

 

[Jimmy2980]

Does it run hot doing anything else that doesn’t involve mowing? No

What size/type of mower? 6’

How close are you mowing and how thick is the grass? 11”. Just topping it.

tell us more details.

 

[85Hokie]

As for the proverbial "gauge" - and infrared thermometer is a NOT contact and even the cheap ones are plus/minus 2% .......

So even if off a bit - it gives you a hellva lot of info.

I gauge that dips its wick into the coolant has the same problem with accuracy as the infrared...... most OEM do NOT place the actual temps ON THE GAUGE ..... a start and then a long run until red - you have no idea what RED is!!!!!!!!

NOW - getting down to brass tacks - when the puppy is hot - shoot the top NECK of the radiator ......... should be something close to 200F ......... THEN SHOOT the bottom neck ....... it better be 80-100F LOWER.

IF not......... you can have several problems - but NUMBER ONE, a clogged radiator. PERIOD.


REMOVE it ,,,,,,,,,,,,,,,,, clean it , clean it again and then a 3rd time - hell you should be able to see sunlight through it at 100%

 

[Jimmy2980]

Thank you! I will try to shoot those points. I will use some temperature crayons also.

 

[TheOldHokie]

Thank you! I will try to shoot those points. I will use some temperature crayons also.

You will get a much better number by installing a gauge in place of the sender.

Dan