Some of you may know I have an EX60-2 with a 2.2L Kubota engine swap. The original engine was a 3.0L and the original cooling system is in use. The problem is I can't get the engine to build much heat. I ran it for 3hrs straight today in 38f weather and the thermostat housing was reading 120 and the temp needle had barely risen. Since the coolant is also my heat source for the cab I'd like to get this temp up. I was thinking of just blocking off part of the radiator but that would also hamper the oil cooler performance. The oil was about 105f which is pretty low so maybe it wouldn't be an issue. Our weather in SW Washington isn't all that cold but maybe some cold weather measure are necessary for a cold blooded machine?
Sounds to me like the thermostat could be letting water past? Really it shouldn't make much difference how big the cooling system is if the thermostat is blocking it off until the desired temperature is reached. Is it a low temperature one, they can vary a bit?
Yeah, if you're driving the same hydraulic pumps with the smaller engine, it should have no trouble reaching operating temp. Take out the thermostat, confirm that it's the right one, and test it in hot water to see if it stays closed. Could even be a missing gasket, or possibly a poorly plumbed heater hose or tank heater.
Good ideas. I was thinking the thermostat might be malfunctioning. If it's stuck open I could see this happening. I'll report back in a few days when I have a chance to work on it.
The top tank of the thermostat should stay dead cold until the thermostat opens, then get hot all in a rush along with blowing hot air. This will happen even if the engine is running say 1800 RPM no load because that is what I work on (generators). It may get slightly warm if the thermostat has a bleed hole but most Japanese engines have a jiggle ball that stays mostly closed. If the top tank is getting warm or warm air from the radiator before complete warmup then it is a thermostat issue. Of course some applications have bypass bleeders and such so you need to be thorough. Most failed thermostats I have messed with will go back to working mostly correctly when you go to check them with hot water out of the engine, the stickiness is intermittent.
Another thing to check on if not getting good heat out of cab heater is make sure the heater and lines are not air locked. Sometimes due to the routing of lines you can get air pockets in a system and only have partial flow through core. Of course you need good heat from the engine first!
May not have a thermostat in it, which besides not letting the engine heat up will probably kill heater flow due to lack of back pressure. YMMV
Big thing with no T-stat in hot weather found they flow TOO Fast and actually make a engine heat faster where in Cold weather never get warm.
So the thermostat was froze wide open. Got that replaced with a 180F thermostat. Engine comes up to temp nicely now. Still don’t have much heat if any. The water pump on the engine has no provision for heater core lines. I have T’s in the upper and lower hose that the core hoses are plumbed into. I think without some sort of restrictor in the upper hose it’s just going to pass on by the smaller hose. I could weld something in the upper T. Just not sure what size orifice would be safe. It’s a 1 3/4 - 1 3/4 - 5/8 fitting. The other option would be a small pump that I could power up with the fan knob.
Something like this. https://www.amazon.com/dp/B07PFTVYF4/ref=cm_sw_r_cp_apa_fabt1_HX2RFb5BDZMSW?_encoding=UTF8&psc=1
I did flush the core with a garden hose before hooking it up and it flowed clear.
Im rethinking this. I could use heater core hoses as my bypass circuit on the water pump. I’d have to adapt the hose size but it wouldn’t be that hard. Does adjusting the temp to cold on the heater control block off water flow through the core?
You will have to be before the Thermostat to get flow thru the core while thermostat is closed Finding a access port at WP suction then another near water jacket region around the stat is the only way will circulate hot water consistently
I would think I would be trying to have one heater hose tee'd into the lower radiator line to the engine and then find some place, maybe in the cylinder head to connect the other line to heater, the higher up on the engine the better. Also what ever way you connect it be careful on how you route your lines so as to not have places where you could get air trapped and bleed the lines and core to be sure there is no air in it.
Show me some pictures of the engine and I can probably identify good spots for heater hoses. Is the engine like this one? If so, the bypass hose from the tstat housing to water pump is the spot to put it and it will roast you out of the cab. If the core can be shut off, then install two tees with a restrictor for continuous bypass. All it has to be is a chunk of steel blocking the bypass hose with a 1/4" hole drilled in it.
That's the engine. The core can be shut off after looking at it. Would this work or would there need to be a check valve in one of the hoses to direct flow?
That will work. No valves needed. Just a hole in the restrictor so a bit of water can bypass at all times and keep the base of the thermostat at engine temperature so it opens when the engine gets hot. The rest of the water goes through the heater core if the valve is open. Engine water pumps move a lot of water.
Surely you have a plugged threaded port on the head somewhere? any port on the head would be better than messing with the bypass in my opinion, just to keep the install clean and not make somebody scratch their head down the road.
I agree but a lot of these small engines don't have a good heater discharge port. Sometimes they resort to using freeze plugs with a pipe thread in the middle if they need a block heater, etc. but I don't know where you get them. Plus that would not be a good spot to get water for a heater. It may be that there is another threaded plug on the thermostat housing, Isuzu did that a lot. But you know the bypass will work and it is there already.
I'll pick up some barbed fittings and some hose and report back. Thanks guys.
Got it plumbed and it the heat is blasting now. Air was still blowing cool even after I had some engine temp, I cracked on of the lines and some air hissed out and immediately it started blowing hot. Thanks for the help on the bypass setup. It worked well.
Watch that that hose does not rub through on that alternator bracket or anything else sharp.
I have some hose protector I need to put on it, I just wanted to see if it worked