I recently purchased a 97 Samsung se210. It’s got the 6th Cummins that is supposed to be freshly rebuilt. Machine has 8k hrs on the rest. Have been having a problem with it overheating. Under a full load it will overheat in about 15 mins. With little to no load it can take 45 min plus to overheat. I have pressure tested the cooling system and it holds pressure. While checking the thermostat found that there wasn’t one so installed new 170 degree thermostat. I do believe the water pump is working as it should as I can see the coolant movement in the radiator. The radiator is clean and should get air flow as intended. The fan does not have a clutch and works as it should. I do believe that the motor is just rebuilt. And the oil is not contaminated. Seems to run fine and not make any odd smoke. Not really sure where to go from here. Any suggestions would be great. Thanks, matt
What are the actual temperatures at the cylinder head, upper and lower radiator hose, ect? You should be able to find those with a infrared temp gun. If it is actually overheating what is the temperature difference between the radiator inlet and outlet?
When I bought the machine there was no temp gauge, I installed a new one at the rear right cylinder head and it’s gotten to 220 before I shut it off. It did blow out the overflow once on me and got immediately shut off. I have it gun and the gauge seems to be pretty accurate and the engine seems to be pretty consistent, as when the gauge reads 220 the whole engine seems to be close to that. I have almost no access to the radiator. I can see that the top of rad will match the engine. I have not been able to get a reading from bottom of radiator. For some reason it never occurred to me to check lower rad hose. I’ll try that tomorrow.
How do you know the radiator is clean? They can get plugged up pretty bad on the inside and it is very difficult to see or clean. I have completely removed radiators to clean them because you cannot clean it properly in the machine.
I was referring to the exterior. As there isn’t dirt or pollen blocking the airflow thru the fins. I have no idea about the inside. But I do know, when there was no thermostat installed there was significant flow coming into the radiator. Led me to believe there was not a blockage. But I may be wrong. I’m far from an expert on these.
I am referring to the exterior, can you see the inside (engine side) of the radiator? If somebody shines a light on the inside while you look on the outside can you see through the fins, especially around the edges? I don't want to be a knucklehead, but if you have "almost no access" to the radiator how do you know it's clean?
I shined a light from the outside and looked in thru the hydraulic cooler. Also I can see straight down between the rad and hydraulic cooler. I can’t see much but that the front of rad is clean. There’s no pollen or anything stuck. I’ll try and have someone hold it inside while I look from the outside tomorrow and report back. I’ll also check on that lower hose temp. I appreciate the help. I’ve been questioning the performance of the radiator too. I hate just tearing into things without verifying the cause of the problem.
Also if it helps, the engine will sit at operating temp (170) for a while before it starts climbing again. I assumed until all the cold coolant from the radiator heated after the thermostat opened. Made me think wasn’t a circulation issue.
Are the top, bottom and sides of the radiators blocked up with foam? It makes a difference. the fan will suck air via the path of least resistance even if it means the longest, I have the same machine and it runs nice and cool after I pulled the radiators, cleaned externals and painted. I used those long skinny foam toys kids use in swimming pools, not sure the name but they are similar size to a baseball bat. I’m Pritty sure they‘re closed cell. I cut them in half and siliconed in place with the really sticky black stuff. The top radiator hose has a few awkward bends in it And could be kinked. I couldn’t get the correct aftermarket equivalent but was able to find one similar at the local hose shop But problem was bending to fit put a kink in it and restricted flow. To overcome this I put a large spring fitting inside to hold it open. Otherwise check valve clearances and belts are not slipping. Then go looking at there core.
Good day I suggest you take a close look at the air filter induction system, be sure this is not drawing in warm air. Kind regards Uffex
Seeing as you have already eliminated the real obvious stuff, I don't think you will be losing much if you start digging into the radiator a bit. I would at least start getting panels pulled off so you can get a solid visual of the radiator. You almost have to pull the radiators every couple years to clean them anyway. It will take time, but you shouldn't have to start spending money yet. For reference sake it would be worth getting a good temperature reading from the radiator inlet and outlet before you take much apart. 170 seems a little cold for operating temp, where is that spec from?
If you can't get to the radiator bottom hose, you can take the temp at the water pump inlet from the lower hose. That temp along with the rest of the engine and thermostat outlet being 220 will hint at what's going on. Could you see the tubes inside the radiator? did they look clean? have you drained the antifreeze to check for sediment?
The fan has a big metal shroud all the way around so air can only come thru the radiator
I have not drained the radiator, but coolant looks to be fresh.
170 was the only thermostat available. It did cross reference to the part number in the manual. But I’m not sure if that’s what originally came in it or not I ram machine this morning. Let the temp gauge get to 200 and shut it off. Cylinder head temp was 220 across the whole head. The upper rad hose read 185. The top of radiator, where the cap is read 200 The lower hose read 163. This was after about 20 min running under mixed load. The machine seemed to make significantly more smoke today than it ever has. Usually just black smoke under heavy load. Today was a lot more of gray. Not sure what to think of that. I got a video of it but not sure how to post
post the video to youtube and link here. The radiator hose isn't the best place to check because the rubber is insulating, but the lower hose is 20 degrees lower than the upper hose, so that seems good. The radiator could still be plugged, it would have to be equally plugged on both the air and the water side to give you those temps.