IHI 35N Overheating

This unit has a Isuzu 3LD1 engine and an overheating problem I've been trying to figure out for several years. It starts great and runs great but starts heating up past 190 while working it if the ambient air temp is over about 55-60F. I eventually have to run it with the hood open and if the temp is over 80 or so I can only work it a half day. It cools down to normal operating temp if I idle it with the hood open. Here's what I've thrown at it so far:

1) New radiator cap
2) New thermostat and I verified that it works.
3) New water pump
4) Rodded out radiator
5) New muffler
6) Tested for leaking head gasket
7) Added aftermarket temp gauge to verify the factory gauge is working properly
8) Cooling system flushed out several times over the last few years

I'm out of ideas. it doesn't leak a drop of coolant, and it used to run on the cooler side even on a hot day until something unknown happened. Does anyone haven any ideas? Would an out of time injection pump cause overheating? The exhaust smells like burning oil, but the engine doesn't burn any oil. Don't know if that could be a clue.

If anyone might have any suggestions on where to go from here I'm all ears and would very much appreciate any help.

Can you loosen the injector lines at the injector to disable one cylinder at a time? that might make the smell go away and tell you one of the injectors is bad. A drippy injector could possibly cause it to run hotter and smell like burning oil.

Or pull the injectors and get them checked, or try a tank of biodiesel with some diesel injector cleaner and run it hard for a tank. don't let the biodiesel sit and turn to junk.

Thanks for the info. I'll look into the injectors when I get a chance. I appreciate just being pointed in a new direction. This overheating problem has been driving me nuts for too long.

I would check the injectors. I had a 35J that had that issue (overheating and injector failure). If I recall and if it is the same Isuzu engine, the engine has kind of complicated injection system. Once I had the injectors fixed it was good. I would also contact Compact Equipment Sales in Ky. Those guys are rock solid, if it deals with an IHI they can help.

I had an overheating issue that was related to two things that have nothing to do with coolant.. one the inside of the machine had so much dirt, grease, and mud that the hydraulic lines were heating up and causing the internal temperature within the engine bay to increase, also I had leaking hydraulic orings leaking internally making the hydraulic pump work harder therefore increasing heat in the compartment as well. I only mention these because you have no signs that point to coolant issues and opening the engine bay door appears to help. Just a thought.

Thanks for the replies. The engine and everything else under the hood is really clean. I just have a little oil leak coming from a bad oil pressure sensor that's making a little bit of a mess but i'll fix that when I get a new sensor. The hydraulics are strong and any leak down is very minimal so I don't think there would be any issue with that. I'll look into the injectors next.

Air filters

This overheating problem has been giving me a headache for several years. The air filters have been cleaned and replaced many times over those years.

try a new radiator cap with the proper pressure rating ?

yep, a new proper pressure radiator cap from the dealer was the very first part I threw at it.

Your description of your problem points to something in the engine bay heating the engine up externally, as to say its not a coolant issue.

What kind of fan do you have on machine ,direct drive,clutch drive ,thermostatically controlled?

Did you find out about the problem? Mine also goes to 100 degrees c

No I haven't gotten it fixed yet. I'm going to try replacing the fuel injectors and see if that helps. I just got the parts but don't have the time to do it at the moment.

I finally took my injectors out and found something that doesn't look good. This is my first time trying to upload pictures so this is a test.

Ok I think I got the pictures figured out. So these holes are supposed to be round, well one is anyway. So I have a couple questions. First, what causes this metal to be eaten away.....or burned away? Is this from bad spray patterns from the injectors? And my second question is can I put the new injectors in and run it without any problems or do I need a new cylinder head for it to work properly? It looks like all the sealing surfaces are in good shape.

I think those are replaceable injector seat seals, done with the head on. I know on Cummins B motors, they get replaced when changing injectors, and, on a Cummins B, they pull right out.
#66, but I can't find part number or instructions, yet.

And, this...

Are you talking about the heat shield, which looks like part 66 on your diagram? The pictures I took are with the heat shields removed. I first thought I might have broken this metal while removing them because they were a pain in the ass to remove, especially the one that came out of the hole with the biggest section of metal missing, that one was an absolute BITCH to get out. After looking at it a little closer, that metal is thicker than I first thought so there is no way I could have broken it.

I worked the excavator today after installing the new injectors and there is no change. it's heating up like usual. At this point of my frustration I might just work it until it blows up and find another excavator. That would be a shame though because everything else works great other than the overheating issue.