L3750 Running Hot

[Learning to Farm]

Ok, so Saturday I noticed that it was running with the temp gauge at 3/4 (so half way above the middle hash). I replaced the fan belt in the fall, per the suggestion of my mechanic, as it was running really high, almost red, and that fixed it then. He said that i might have to tighten it once it was broken in so Saturday I did that. Still ran at 3/4, under minimal load (light mowing for 8-10 min). Plan is to test the coolant, replace if needed. If that doesnt work, flush system. If that doesn't work, thermostat replacement. If that dosen't work, pump replacement.

Does this sound like a logical plan? I haven't called the magic tool man, as I don't want to bother him with something that is a simple fix. He doesn't charge me to point me in the right direction, but it is something I like to only do when I need him.

Anyone see a problem with this plan or can suggest something different?

Thanks!

 

[kthompson]

So many post here on running hot:
So you have checked the coolant level, belt. So now check the radiator fins for trash and even if it looks clean (you are mowing which stirs up trash and dust) lower pressure wash the fins out but not spraying hot engine or other parts of the engine system,check the air filter (clogged air filter will cause this also). You can use compressed air to clean the air filter and also the radiator fins.

 

[Fallon]

Check the fins. Even with the screens on my L4060 (only on 2 of the 4 radiator type cores up front) they all pack in with dust & other debris. Water may or may not be more effective than air. Just dont use to much pressure & bend up fins.

 

[Learning to Farm]

Thanks, I forgot to mention that I did use the air compressor to blow everything out while waiting for it to cool down to adjust the belt. There was a bit of dust, a few seed and random dead bugs, but nothing super thick. The air filters (both primary and secondary) and oil were changed about 20 hrs ago, as part of annual maintenance. It is not a hard used machine, just turning the manure pile every 8 weeks or so, pasture mowing after horses are done (so pretty low) and ring dragging. Pasture ground is mostly flat and rolling 14 acres.

 

[Fallon]

Thanks, I forgot to mention that I did use the air compressor to blow everything out while waiting for it to cool down to adjust the belt. There was a bit of dust, a few seed and random dead bugs, but nothing super thick. The air filters (both primary and secondary) and oil were changed about 20 hrs ago, as part of annual maintenance. It is not a hard used machine, just turning the manure pile every 8 weeks or so, pasture mowing after horses are done (so pretty low) and ring dragging. Pasture ground is mostly flat and rolling 14 acres.

Still, take a close look at the fins. Dust can pack in & moisture makes it cake on hard. Compressed air may not blow it out. Had issues like that myself recently. Compressed air blowouts didnt resolve the issues. Came back & further inspection showed packed dirt & dust still there. Took a while with the hose to turn it to mud & wash it out.

 

[rbargeron]

L3750's have been in service nearly 40 years, so the radiator's tubes may be partially clogged. My suggestion would be to have a radiator shop recondition it, which usually involves boiling it out, flow-checking, repairing any damaged tubes, etc.

 

[radios1]

wash the radiator from the engine compartment forward, because debris comes from the front, and gets pulled into the radiator by the fan..

 

[rbargeron]

Most L3750's have been in service 30+ years, so its radiator tubes may be partially clogged. My suggestion would be to have a radiator shop recondition it, which usually involves boiling it out, flow-checking, repairing any damaged tubes, etc.

 

[art]

Has the engine developed any smoke in the exhaust? A bad injector can cause an engine to run warm! Two things, potential extra fuel, or lack of it and increased friction.

 

[kthompson]

I agree with Fallon but also do not agree with you the air filter has to be clean as it was only changed 20 or so hours back and it MAY be very clean. However any type of work producing dust can clog a filter rather quickly. Dirt or mowing of dry material both produce dust and or debris that can clog a filter quicker than might be expected. Use a detergent to soften any build up of debris and dirt in the fins and then plenty water flow but low pressure as Fallon has suggested and radios1.

Do hope you well in your hunt on the problem.