Just wondering if anyone has had a faulty water temp sensor & if faulty would this cause the guage to go up & the buzzer go off after 1/2 hour of running. Coolant is OK on inspection, thermostat fine & coolant not overflowing to the holding tank?? any thoughts.
Highly unlikely to be the gauge or sensor if it takes that long to max out. Try using an infra-red heat gun and when the buzzer is going off shoot the temperature of the hose from the thermostat housing to the radiator and the hose back from the radiator to the engine. Also please post a Serial Number. It mkaes it easier to find information.
Thanks Nige. I will buy a infra-red heat gun & check. Serial No: 8JR01832
Hello Nige I put the infra red gun on my CAT 312. After half an hour running. Readings 1/. Thermo to Radiator 91 F- 96F 2/. Back to engine hose: 113-107 F. In 1 hour reading was 1/. 32-34 C & Back to pump 43C...... The Guage stayed just under 1/2 level. Im wondering what have I done?? as not overheating after an hour running......I will need to run it longer to see id any changes I guess
I’m sorry those numbers make no sense. With a measured temperature on the return line from the radiator to the engine HIGHER than from the engine to the radiator that would indicate the radiator putting heat into the coolant not taking it out.
Thanks. My next move will be clean radiator & oil cooler in front as hard to get the bottom in between. Fan OK & Belts. Can you tell me is there any pressure when I disconnect the oil cooler or can I just unbolt & catch oil? as have no manual.
Being made up of so many indicivual elements those cooling packs are impossible to clean when installed. You need the whole thing on the ground and disassembled before you attempt to start cleaning otherwise you are wasting your time. Did you carefully read my comments above in reference to your temperature readings.? I will repeat, they make no sense because at face value they show that the radiator putting heat INTO the coolant instead of taking it out, which by all the known laws of physics is impossible.
Yes I understand the cooling in & out not good. Ok will take both out.
It's not just that. The temperature of the outlet is higher than the temperature of the inlet. That ought to be physically impossible. I thought that maybe you had somehow juxtaposed the two sets of readings and put "inlet" where you meant "outlet" and vice versa. To be clear the inlet to the radiator is the hose from the temperature regulator (thermostat) housing shown by the red arrow and the outlet is the hose from the bottom of the radiator to the water pump shown by the blue arrow. This illustration is from the side looking backwards from the front of the machine. After the engine has warmed up the red hose should always be significantly hotter than the blue hose.
Attached the R&I instructions for the oil cooler and radiator.
Thank you very much for your time & effort assisting me. No I got the Lazer readings right. I talked to another old farmer friend whose an ex marine engineer about it as he has an old Kato that still runs after many years. As we get starlings nesting in the engine bays [the cause of many ex fires in NZ] the bottom portion of both radiator/cooler will get clogged up. He told me to do a simple test --clip a sheet of paper between the 2. Lower down all over the radiator to see if blowing or sucking. Its wet here so have to wait a few days until we get better weather....
Special thanks to you again Nige .... makes it so much easier when you get experts like yourself helping a 74 yr old who can pass on these things. In my town we had real good bush mechanics but sad to say those times have changed with the computer age. I'll check back when I get working on it.
Stupid me: I used the lazer higher up on the bottom hose? Lower down after 15 minutes running it read [BLUE] 18 C & top hose [RED] 23 C....Ran air thru cooler & radiator but seems to be sucking if I put paper on the outer oil cooler side. Both sides insulated & under the cooler? We will be taking both rad/cooler out..
OK, so you at least confirmed that the laws of physics are safe for the time being. Let us know what you find when you disassemble the cooling package - post photos.
1/. Cleaned fins on both radiator & cooler. 2/. Foam baffle missing on one side--installed new one. 3/. No foam baffle on engine hood-missing? but baffle on bottom fine 4/. Ran CAT for 2 hours working it--- temp stayed normal & read 41C top & bottom hose 38C. Temp Guage reading stayed under 1/2. [ If the temp went to red I would have put the lazer by the alarm senser?] .....I read missing foam baffles do cause overheating & didnt even know there was a baffle there......Ok for now. NZ CAT dealer wanted $390 for a top baffle so made one? Thank you for the help Nige.
That's far too cold for 2 hours running. It should have been pretty well up to normal operating temperature (85+ DegC) after that amount of time, especially if you were working it. Does it have a temperature regulator (aka thermostat) fitted.?
Ok back to the drawing board thank you. Will run it again end of next week. Thermostat OK & tested. We only ran it on 3 clicks -- ??? not hard work... will get back
Does it have a genuine OEM temperature regulator installed.? What temp did it open at when you tested it.? The OEM P/N is 324-4128. It should open at 82 DegC.
When you say it stayed under half on the gauge it makes me think your laser readings are low. If it was part way up the gauge it must be more than 41c
At 41 degC on the radiator inlet hose, and the gauge in the cab reading normal, I would just interpret that as the thermostat being closed. The warm stuff would be going through the bypass.
Agreed, hence my questions regarding the stat.
Thermstat is in. My friend did a boiling water test & it opened & closed he said. Sorry. Will do a thorough check again next week as working away & or buy a new one. Thanks for your info--appreciate all advice. When you say bypass can you tell me more...I did put the lazer on the thermostat housing by the sensors & was a lot hotter? sorry cant remember the reading.
The bypass is just the route the water takes when it bypasses the radiator, as controlled by the thermostat. Sometimes it’s a hose, other times it’s a passage depending on configuration. Edit: which is kinda why infrared gun readings of the radiator hoses are fairly useless unless the engine is working hard/really warm, to ensure the thermostat is fully open. Only then can you gauge how well the radiator is doing it’s job.
Tested the thermostat & opened around 82-84 but also put a new one in & that was the same. Ran for 3 hours and runs fine now over the half way mark on the guage. All baffles renewed & coolant. Had a CAT mechanic check it who lives in my town & only thing he told me to change was V Belts & one radiator hose. I have also changed oil in travel motors but hard to buy the 12mm hex plugs in NZ??? although mine Ok for now. I am doing changes every 250 hours & oil changes every 50 hours? Since Oct 2020 Ive only done 157 hours???? Thanks once again for your help....
If the v-belts were worn/loose that kinda explains why the gage read hot and the radiator hoses read cold. Glad you got it sorted anyway. If it plays up again you have an infrared gun now. Edit: good idea to change fuel filters every year no matter how often you use it. Specially in your climate.
Thanks Chrisso for your response. Yes Belts old & replacing [see pic] if OK? original Terracat belts $247 + GST. [got these $147-] the young CAT mechanic came & went over it before he hits the mines in Australia? He said if one belt goes the other will go then I have water pump headaches. Fuel filters well do. The lazer gun is a must for all operators as I have certainly learnt a lot from Nige & yourself.....hope others can also gain knowledge...many thanks