Now that a/c season is here, found the engine and hydraulic oil getting on the warm side, and with the a/c temps climb to the max. Just in case anyone else is finding this, I pulled the a/c condensor out of the way and found a very dirty oil cooler which was obstructing a lot of air flow.
My deere dealer mentioned the deere compacts have a bit of a history of heat issues. I remember that it was odd because he is not involved with compact sales, nor am I a potential customer for them. He just kind of mentioned it as an off the cuff remark, left me thinking it must be pretty common for him to mention it out of the blue like he did. Based on the pic, I would guess that black tank in front of the rad (foreground) is a hydraulic oil tank, and vapors come out the vent during normal operation. Get sucked through the rad and you get what you have there. That's just a wild ass guess though. On the other hand, it looks like there may be some seepage coming from above, a leak maybe. OK, i've gone on long enough to convince myself I don't know what i'm saying.... :drinkup
I buy bulk home furnace filter media at the hardware store and cut a patch to cover the radiator core on the dozer (it has a suction fan). Change it out as required. Works like a champ. It appears that your Deere has a suction fan also so it should work for you too. My mini-ex and skid steer have pusher fans so I can't do it there.