Happy New Years Folks! Looking for any ideas you guys might have concerning my current headache. My 312CL doesn't want to warm up to operating temperature. Seemed like a no brainer, must be the thermostat is stuck open right? Ya, never seems to be that easy for me. Took the old thermostat out and placed it in pot of water right beside the new one and heated it up. The way they opened and closed was pretty close to identical. "Now," I know I'm in trouble, but I put the new one in anyway, along with the new seal on one side and new gasket on the other side. I let it run for a couple hours at about 1/2 throttle, but it never came out of the white and made into the green on the gauge. I thought maybe the sending unit or gauge might be screwing up, but checked the temperature of the casting that holds the thermostat with my infrared thermometer while the machine was running and it was only 130 deg F. Any thoughts would be appreciated! Thanks, Mike
Did you have a thermometer in the water to see what temp it actually opened at?
No, I was just trying to verify that it would match the new one.
id feel happy with 130f measured on a outer exposed metal on a day i assume with outside temp of approx 30f with a diesel idle to part throttle that is not being worked. when i work snow storms in my loader down into the zero's and stop for a quick 10 minute break and let it idle for a coffee and pee it'll go almost cold. diesels are a heat motor they do not like idle ( in a perfect world ). my opinion only! work it for 10 mins take another reading bet it goes up !!!
Check the old one again, with a thermometer in the water. If it opens close to what it's suppose to, then you maybe could assume the new stat is good. Not much to really do other than take a bunch of reading with the infrared. Maybe engine just hadn't been worked hard enough to warm up. What was the outside temp while this was going on? Does the heater put out any heat? At 130° it should be lukewarm, if it's cold, I'm going to throw out a suggestion that you might have a head gasket or crack of some sort leaking compression into the coolant and screwing with the circulation. How many hours? 312 not a very big machine, small engines with hours don't warm up very fast.
In another thread it was mentioned that the Cat thermostats are designed to be open at 160 degrees F. The would kind of make sense for you what you are describing as the temp at the thermostat housing and operating in near or sub freezing weather. I think I would run the machine hard for a bit and see what happens. In my opinion if I had a machine running that cool I would look for a 180 degree thermostat.
So is this a new problem ? What temp did it run before ? S/N help to give better response's as to what might be going on. Is the fan direct drive or thermostatically controlled and stuck on ? What happens when you put it to work ? Whats the outdoor ambient temp when you are testing this ?
What temp are your thermostats stamped. I just replaced mine but for different reasons. Today it was 28F out and my 320D runs 160f. Runs the same temp in the summer. I still think that's too cool. Are you getting heat out of the vents?
i cant wait till wizz tells us what happens when he works the machine???
I put the old thermostat back in the pot and heated it up. It's opening around 165 which is pretty close to the 160 it's designed for. I took the machine out and ran it for a little while this morning as I was summoned to a coke spill where a semi dump rolled over on an on ramp. I loaded the spilled coke on another trailer without hitting the green on the gauge. Hardly a workout since the coke is so light, but I still think it should have made into the operating range. Ambient temperature isn't likely to be the problem as she has been running cool, ( or at least appearing to run cool), for a couple months. The machine has always ran in the middle of the green since it was new prior to this. I think the temp this morning was around 28. The heater is putting out some heat, but I had the front window up and the lower glass removed today so I could see well. That makes it kind of hard to judge how well the heater is working and couldn't fool around with it since the authorities had the ramp closed and I was surrounded by troopers would wanted the clean up done and me out of the way! Maybe I should close it up and let it run with the heater on to see how well the cab warms up. It seems to me if there was a circulation problem it would get hot instead of running cold, but I have been wrong MANY times before. The SN is CAT0312CKCBA02833 and it is a direct fan, (Although that question got my hopes up for a sec). Does anybody know how to diagnose the temp sending unit,(I'm still leaning a little toward the fact the gauge might be misleading me). I appreciate all you thoughts and welcome any additional ideas.
Just to satisfy Turfblazer, I promise I'll move a couple piles of dirt around tomorrow!
Find the sensor and shoot the casting around it with the infrared. I would think even though the coke was light, running and operating it should get it up to temp. Good work verifying the old stat was opening properly. Could you tell if it looked like it was sealing properly?
even with the light working ya gave it today and now a little history of over the last couple months i would conclude you have a sending unit going out of calibration. over all my years of temp issues and after 1st always changing stats to be safe ( they used to be a regular maintenance item !!! ) but who does that these days ??? #2 to look at is the sending unit. i'am really racking the old noggen but i cant remember a electronic sending unit fail with a reading hotter???. use the infrared dig the dirt, sending unit is cheap. running cold is better then hot !!!
i forgot to mention clean contacts at sending unit with some wd 40 wiggle or push off and on a few times to insure good contact before buying new sending unit. in the old days ya could just ground the positive wire and gauge would go to hot but ya can't do that now
Some engines have too large a bypass line so you always get coolant flow to the radiator, even with the thermostat totally closed. Try covering the lower half of the radiator with cardboard, just don't block the oil cooler, see if that doesn't help. Adjust to suit, works just like the winter fronts you see on the highway trucks.
Ok so start it up, leave it idle and when your up to the 130 temp it only seems to get to, touch the upper rad hose and see how warm it is. It should still be coldish but if it is also at 130 then you are leaking coolant by the thermostat As mentioned they are not a perfect seal so there will always be some bypassing but should not be at the same temp as the engine before the thermostat opens
How's your coolant level. If it's a bit low you will have now heat. Probably not your issue but check it out its happened to me before
Today I moved dirt for half a hour. The cab warmed up nicely, but the gauge still didn't come into the operating range. Took an infrared shot in the heater vent which was 122. The temperature at the water jacket next to the temperature sending unit made it up to 154 and the top radiator hose was at 89.
From those numbers it would appear that the thermostat isn't opening, the temp you see on the top hose is the small amount of coolant flow that is bypassing the closed thermostat. You didn't take the temperature of the bottom radiator hose by any chance..? If that temp is say 20 degrees or more lower than the top hose temperature then you would benefit greatly by blanking off at least 50% of the radiator area. For the purpose of a test a piece of cardboard would work fine.
I personally would not do any radiator blocking at this point with temps in the 20,s. Let the stat do it's job! Blocking rads are a primary practice for vehicles that travel down a road and have air forced thru the rad. I do not block my loader rad in winter ( I have a fixed fan) unless it's 10f or below , one time I blocked 100% it was -20f and snowing very hard, ice was building up on blades of fan and hitting the shroud, ya needed the blow back heat to keep the fan turning.
I was simply suggesting blocking part of the rad temporarily with a piece of cardboard, run the test again and see what the temperatures do. In one of his earlier posts the OP indicated he had a direct-driven (as opposed to demand) fan. Running a quick test would show immediately if the issue is being caused by too much cold air flowing through the radiator.
Not much else it can be besides too much cold air going over the engine, it doesn't matter what goes over the radiator with the tstat working right, which it seems to be doing. Engine too efficient? not enough hydraulic drag? Next time you run it for an hour turn the heater off toward the end and see if it will get into the green. Under some conditions the heater core is adequate cooling... with a diesel and a good heater maybe more than enough??? Winter fronts are usually put on depending on how cold the driver feels, just take a look the next time you're going down the interstate on a 40F day. The trucks with a closed front will all have southern plates. Leave a few inches of all the radiator and oil cooler tubes exposed and you'll be fine at 20F, you're going to be watching the gauge like a hawk anyway, and shooting temps on the engine too.
shoot the block at sending unit again and the block at the stat ( inside side of stat ) not outside round part they should be pretty close, also the output metal nipple hose at the block going to the heater should be the same also, all at the same time . if all 3 are close your in good shape ( good circulation ) and you most likely have a sending unit thats only off a little . because i'd assume 160f should be the normal ( green ) in your gauge ???? your hitting 154 that would be close to the bottom of the green ??? i agree with the other guy a heater core in fact is a radiator . have you by chance done anything that might of exposed your heater core hoses to air ???? if you need more heat in cab in future put pipe insulation on them. keep useing your infrared and keep a eye on it . i really dont think your in that bad a shape .. you really need another guy with a similar model and year to chime in on his machine ??? ok i'am gone beer and pizza
I'm working by myself loading a tandem with my 314DLCR with logs. I leave the excavator running while I drive a mile and dump. Even though I shoved a tarp in the radiator compartment to cover up the radiator I'm lucky to see one green bar on the temp Guage. This is at minus 7 Celsius or so. Even when working steady all day with the radiator covered I have 3 green bars. Stop for 5 minutes and it's 2 bars. I don't like running a diesel cold. Might have to fabricate some covers for the top and bottom of the engine but I'm hoping to be finished my work after another week or so.
thanks dave its sure sounds like he's running about the same as you are . -7c is about 19f. so wizz there's a real world compare at least 1 so far. i think your fine if anything just if there was a way somehow to help keep the air off the motor and try the cardboard suggestion but do it in steps according to the outside temp!!! like another guy said if the bypass is letting a lot of hot water into rad it'll never warm up if it gets colder and your gonna have too block rad . you just have to insure those other 3 areas i spoke of before are about the same temp once you fine they stay the same with each other whatever you do with blocking your golden then go back to watching your gauge like a good operator does!!!. in my opinion only. all diesels have oversized cooling systems mainly engineered for summer work, now we have the reverse situation here , get into the newer diesels the newer emissions they are not going to tolerate running a engine cold so they dumped the fixed fan to stop any cold air from being blown around the engine compartment they let the stat do its job to get the motor up to temp as soon as possible then it lets the rad also get up to temp as soon as possible than the rad coolant temp switch turns on the fan to cool the rad , besides the fuel savings not turning a fan 100% of the time it keeps the engine at a more higher more steady temperature. hell if ya wanted you could retro yours with not alot of bucks. with my loader i have it easy i have a swing gate on the rear and i use the foam from a couch cushion its spongey enough to fill the void in one piece and cover the whole rad when its real cold and when its a little warmer i can fold it down and its compresses enough not to be too tight when i close the gate , adjustments in 30 secs . mines a push fan so warm comes out the rear .
nige had the right idea so i apologize , i wanted to be positive for wizz that his gauge was reading somewhat correctly before getting ahead of ourselves in the correct diagnosis. d3dave helped sway my vote even more now. let us know what happens wizz.
Who knows these cats are all over the place. Like I said my 320D runs about 160-165f all the time even in the winter just idling but I do have a 160f Stat in which I feel is at least 20deg to cool but cat knows better then me.
So I believe I have gotten to the bottom of it! I put a piece of cardboard in front of the radiator and got the temp to rise according to the infrared thermometer. The gauge still didn't show it. So I called tech support at the local Cat dealer and found out if I grounded the grey wire on the sending unit the temp gauge should spike. And if this were the case, then the sending unit was probably the culprit. Grounding the wire pegged the gauge and they had a sending unit in stock, so I put it in and the gauge jumped right up to where I'm use to seeing it. So it was running at the correct temp all along, just not showing correctly at the gauge. What still puzzles me is the fact that the infrared thermometer still shows the temperature of the casting surrounding the thermostat to be in the 130 deg f range while the gauge shows 4 bars into the green. This isn't enough heat to open thermostat and the top radiator hose is substantially cooler. Hard for me to believe the machine was designed to run this cool. Anybody know what temperatures match up to bars on the gauge?
Always nice to hear the solution to a problem. Sometimes the simple things give the best results. Regarding your temp gun. Are you sure it has a beam that is tightly enough focused to generate a good temp reading...? I've seen some that had a very wide angle sensor that took an average of what it was seeing as a result. As a suggestion try holding the temp gun almost touching what you're trying to measure the temperature of and see if it makes any difference.
Also with infrared thermometer the finish or even color of object being measured can make a difference. The term for this is emissivity. And if you want to get more confused try understanding this: According to the Stefan-Boltzmann Law, radiant power is proportional to the fourth power of temperature, so when the measurement surface has both hot and cold areas, the indicated temperature may be higher than the actual average temperature, and closer to fourth-power mean average. But like Nige says, move in close to see if you get a more accurate measurement. Also keep it close to perpendicular to avoid averaging in something cold near by. I think that is what that that quote I posted could be saying
holy ship batman robin was thinking right from the beginning!!!! glad to here ya got it !!!! your motor was happy all along and the stat was doing its job just fine . i;am glad cat told you you were able to ground a wire , that makes it very straight forward , sending unit are usually the 2nd place to go , right after the 1st place the stat. happy digging
one thing i could add , i was doing some duct work on my garage oil furnace today a used one i bought and i could't keep my hand on the sheet metal ( clean air out) while it was running ( to hot) i'am pretty good with guessing temps with how long i can keep my hand on a surface but just to check i got out my fluke and like the other guy mentioned it was all over the place with shinny metal , no matter how close or far i got , so i got the direct contact wire thermocouple for it out and it was running at 175f way hotter then i wanted or thought . after some investigation i found that the fan speed was set to medium , so i reset the wire to med hi and it brought the temp right into 140f (perfect) which happens to be the temp i can keep my hand (palm)on the metal. guess im say wizz if you can keep your hand on the stat houseing your motors too cold , if you can keep it there for maybe 3 sec's it might be 150 , if only 1 sec it might be 170 . ???? we all feel pain different but you get the idea ! give it a try ! keep a cold beer in the other hand just in case !! later have a good day.
Does anyone know why these things have 160 stats?
I have no knowledge of why the manufacturer actually uses the 160's, but if asked to hazard a guess I would guess that it helps lower the heat load to get rid of due to the big oil coolers generally right in front of the radiator?
Best place to spot the I/Red heat gun is on the Engine Oil filter (spin on) this will give a clear indication of the oil and water temps including the T/Stat movement, the water cools the E/Oil giving the heat gun a very easy path to investigate working temperature without any confusing messing about,the temp should go up and down as the T/Stat works all easy to see off the O/filter side, red dotting any part of the engine until this test is done is pointless and only needing further testing if this heat test is out of scope. don't waste your time. tctractors
Interesting idea TCT. I'll have to give it a try. Thanks mate.
If the engine oil is water cooled it is going to reach the same temp' as the water that is going to cool it, if the engine is running an 86 or 88 T,stat' the side of the oil filter will show perfectly the water activity and effect when measured with a heat gun, as the stat opens the oil temp drops due to the colder water being pumped through the cooler, the oil temp will usually drop to around 80-82 deg' before going up to 86 -88 deg then cooling again as the stat opens, if this test is within scope then no other heat gun activity is needed other than having a play about?? tctractors