Hey guys....could use a lil advice on my 2002 CAT 301.5. My friend and I bought a used 301.5 this winter to do a few odd jobs that both of us had. I finally got around to using it the other day and noticed after about 30 minutes of use it would run hot. I took a digital thermal gun and shot the engine (210f) and then the neck of the radiator (175f) the core of the radiator (150f) and the bottom tank (165f). I could tell the water pump had recently been replaced so I assumed it was good. You can bring the engine temp down immediately by turning on the heat in the cab....it was 91 degrees out so I really didn't need the heat on too bad..lol! The way the heater core for the cab is plumbed directly into the water pump that tells me that the water pump was doing its job. Today I pulled the thermostat and put it in a pan of water and brought it to 190 degrees, the thermostat opened as it should. This basically leaves the radiator as the culprit correct? I washed out the fins with hot soapy water before removing the thermostat and it was clean. I can see in the top tank and there is no corrosion or calcium built up inside. Would it be beneficial to remove the radiator and have it boiled? It looks like a TOTAL PITA to get the radiator out! What am I missing? The only thing I thought about after disassembly was wether or not the fan blade was installed properly? HELP! Junkman Sent from my iPad using Tapatalk
You might also want to check the hoses to and from the radiator. One of them may have a flap inside blocking the flow. Checking the fan is a good thought too. Good luck, Rick
That's the only thing that makes any sense to me. It sounds like blocked water flow with those temps, and the fact that the heater will cool it off. I agree that the water pump is working if the heater will cool it off like that. Maybe take the hoses off and check for delamination, and blow out the radiator at the same time with a garden hose and a blow gun stuffed into the bottom outlet with a rag. Wait for the water to run out the top, then give it a little blast of air, repeat.
Fan belt condition and tension maybe..? Have you taken a good look at the air flow through the radiator..? If it's clean inside my suspicions would lie with the outside. It's almost impossible to check the external condition without removing it TBH.
Thanks guys, the fan belt looks new, it was banjo tight. The radiator has the oil cooler partially blocking the front of it but from the inside it looks good. I am going to inspect the hoses tomorrow and have a look at the fan blade to determine by paint wear if the PO could have put it on backwards while replacing the water pump. I am not looking forward to pulling the radiator as it looks like the cab may need to come off Sent from my iPhone using Tapatalk
If the top tank is 175 and the bottom tank is reading 165, why would that be hot? Sounds more like the problem is internal to the engine to me, or as suggested reduced flow to the radiator. I would think that if the radiator were plugged that the top tank would be way hot with the bottom tank much cooler?
Second that. Unless you can see light through it to tell, then you have to assume that it's plugged up pretty good. Would it be easier to take the oil cooler out to get access to inspect/clean the radiator than removing the radiator. Can you put a shop light next to the fan, and get close enough to the other side to see through it?
I think I can move the cooler out of the way, I also have a little more real estate to work with now that the fan shroud, blade and water pump have been removed. I washed the radiator out pretty good prior to today's tear down. As long as it took for it to actually exceed "normal" operating temperature the problem has to be something simple......it is just being a booger to find! Sent from my iPad using Tapatalk
Sounds like pretty normal temps to me. The disparity in your temp readings could likely result from the different materials you scanned (cast iron-aluminum-brass-copper etc.). The digital thermometers are sensitive to the different emissivities of the various materials.Meaning a CI engine block will show a higher temp than an aluminum or brass radiator. Also even a slight change in distance results in averaging a larger area. 190deg. , 210 deg. . Sounds completely normal from here. HTH Jay :usa
I was thinking the same thing...just takes a little longer for me to reach those temps up north.
Same here, those temperatures are well within the normal operating specifications on that machine. I do not see an issue.
Perhaps the gauge or the temperature sensor is bad.
With a 190 degree thermostat I think 210 degrees is excessive, especially no harder than I was working it. Sent from my iPad using Tapatalk
You can compensate for shiny metal surfaces by using a piece of electrical tape as a target. If the radiator is painted then it should read close enough. Or shoot the radiator hoses and heater hoses and go by those temps. There is plenty of overcapacity in most cooling systems so that it shouldn't run hot without some major plugging, the heater cooling it down shows that also. I assume you meant that the gauge was reading higher than the normal range when it was running hot.
Depending where you shot the engine temp I'm thinking (after pondering overnight) that you could likely have a flow issue. If the engine is 210 then the hose leaving the thermostat housing to the rad should also be 210 or as near as damnit. A difference of 10 between inlet and outlet of the radiator indicates it is pretty well working to spec, the optimum is 12. You say it had the water pump replaced. If the old pump had a non-metallic impeller I wonder if it broke and that a passage from the pump could be partially blocked..? Is the replacement pump new or overhauled..? Are you sure it's pumping as it should..? Have you seen what condition it was in internally before installation..? The possibility of the temp sensor being bad is also one that needs to be investigated.
Update.......today I verified the hoses were good, radiator was SPOTLESS, the coolant passages I could see we're clean and clear from obstruction, the belt was good, the fan blade had been installed properly......Sooooooooo.........I put a new t stat in a pot of 190-200 degree water with the old one and verified that it worked similarly to the old one and it did. I installed the new thermostat and reassembled the engine. I put new coolant in it as the old extended life had reached the end of its life and was NASTY! I ran the machine for 20 minutes in the shop to verify I had the coolant level correct and took it to a dirt pile to "play". I ran it for 30-45 min and it never got over 200f with my thermal gun at the port for the coolant temp sensor. The gauge in the cab read approx 2/3 the way up so I have ordered a new sender as I feel that is higher than maybe it should be at 200f.....thoughts? You guys have been a ton of help and I really appreciate all of the comments and advice! junkman Sent from my iPad using Tapatalk
200 with a 190 thermostat and 90+ ambient sounds fine to me, I would run it but keep an eye on it for changes. With the proper coolant and pressure cap you can theoretically run an engine as high as 240 usually before you start boiling and venting steam. Not recommending, lol, just saying. What's you altitude there?
Even if 210 is higher than 'normal' it is certainly not excessive. BTW the thermostat temp. rating is Not the operating temperature,it is merely the point the thermostat opens. This is to allow the engine to reach operating temp quickly,getting all the components to expand to their proper fit & clearances, boiling off undesirable compounds (& water) from the lube oil. Ambient temps & humidity play a major role in a cooling systems performance as does the coolant so variations of 10-40 degrees could occur normally. HTH J :usa
If your ELC was "Nasty" I hope you gave the cooling system a couple of good flushes with clean water before putting the new ELC in........
If I had to bet I would say the new sender wont change anything. Most engines seem to run around 180-190 F and getting up to 230F would be in the red so to have the gauge above the middle at 200 F seem correct to me.
I think we are running into confusion as to what temps we are talking here. I've had an infrared gun for a couple of years now, and I use it for my cool-down idle before shutdown. If I have been working my machine hard in hot ambient temps, I get 165F at hyd oil reservoir (manual states 150F is normal operating temps), 225F or so on lower engine block, 220F on oil pan, 185F on engine block frost plug, 210F on oil filter, 180F on top of water radiator, less further down rad. I pick spots to shoot that are flat (perpendicular to infrared shot). Occasionally, I've gotten readings just over 230F on lower engine block, but the temp comes down after a minute of idling. The initial poster's posted temps were perfect...imho. Once I let my machine idle for cool-down, I get 150F or lower at hyd reservoir. 200F on lower engine block, 195 at oil filter, 170F on top of engine radiator. My temp gauge in cab never ventures out of green...anything past 2/3 green, and I give 'Bobby' a break...a minute or two every 1/2hr to hour brings the temps back down. Running AC means more cool downs as it adds to the engine load.
Yes but most temp senders are basically mounted at or very close to the thermostat housing - reading the temp of the coolant going to the rad and temp the thermostat is seeing. You say your reading 180F at the top of the rad - this is basically the temp the sender is seeing
I was just pointing out what temps one can get from different parts of the engine compartment. You mentioned most engines run around 180-190, which I assumed was the coolant. Then you mention 230, which had me perplexed...coolant temps at that temperature sounds very high...too high. Only my lower engine block sees that temp on hot days and hard hours. My thermostat opens is full open at 185F, according to manual, which jives with the temps I get with gun. My gauge in cab is almost useless...I've just referenced where in green corresponds to approximate temps.
Dang boys.....you guys sure get fired up on a Sunday morning.....holiday weekend nonetheless! From what I am seeing I honestly believe my machine is running fine and I am almost willing to be that a new sender will cure my "gauge reading high issue" I will find out Tuesday when I pick a new one up Sent from my iPhone using Tapatalk
That's the way I'm leaning too. Of course something doesn't add up here (everything's supposedly clean but the gauge reads hot until you turn the heat on?) so it's anybody's guess what part of the picture we're missing. Also agreed that the temps indicated are fine to run at, but to me, the fact that the heater will move the gauge down to normal is NOT right and the cooling system is extremely marginal. Not the way I would want to run it or ESPECIALLY let somebody else run.
Just for giggles, try running it with the radiator cap off once, see what happens.
Oh yeah, he's in IL so most likely the altitude is under 1,000 feet.
Yes, I am approx at 750ft in east central illinois. I did try the radiator cap loose....no change. You were thinking head gasket??? Sent from my iPad using Tapatalk
Combustion leak somewhere, yes. Still sounds like lack of proper flow to me, but as long as it's not getting above 220 I certainly wouldn't be afraid to run it.
Lack of flow would be the only thing I can think of too. If it were in the head and head gasket wouldn't it fill the puke tank with coolant? Had a 3126 in a AgChem Rogator last week that was showing hot with all of the bells and whistles blowing......ended up being the gauge......caught it by letting it sit over night and checking the gauge against the ambient air temp and found it was 15 degrees off. The way the system worked on it was the signal from the sender went to the gauge and the gauge sent the signal to the ecu.....I have never seen one like that before. Sent from my iPad using Tapatalk
Gotta admire your diligence on this one SkiDoo. Re: flow,though you observed the thermostat opening,whose to say it's opening 100%? Say it's short of opening by 10-20%,that won't necessarily equate to 10-20% flow reduction. Could be more or less.Either way may not be perceptible by eye. IIRC the temp sender acts as a variable resistance ground in the gage circuit. A dirty connection or sender (water side) can change the total resistance changing the gage reading as well. How's the battery terminals speaking of electrical grounding, or any grounding straps between components? Cheers :usa
Thanks airborne, I put both thermostats in a pan of water and slowly brought it up to temp, although both of them opened 100% the new t stat started opening later than the old one (I think that is the way I remember it). Like every other component on this mini, the battery is buried so I haven't looked at it in a while. I will verify. I mess with snowmobiles quite a bit (hence the username) and I like the high hp stuff....nitrous... Turbos etc... All of the rotax engines I work on have resistance specs for all of the sensors on them. If I am questioning wether or not a sensor is getting an accurate reading I can consult my service manual and it will give me a relatively tight range of resistance that each sensor is supposed to read in. I have yet to find anything in the CAT world that offers the same info. Sent from my iPad using Tapatalk
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1200 Turbo? What turbo kit? Boost? Meth? What did you tune it with? HP? Nice sled!
Yes, Powderlites stage 1hp, with 50/50 mix of pump gas and race fuel I trail ride it at 10psi (250hp) had a tune for 300hp also on race fuel only. I ran a rapid bike piggyback ignition/fuel programmer. Technology had come along way since I built it. Motec is king now for stand alone ignition systems. I became good friends with Dave Dunn at the mach z shootout in munising mi. I was into the nitrous on 2 strokes for quite a while but boosted four strokes were tough to compete with. Sent from my iPhone using Tapatalk
How does a bad sensor or gauge explain the heater cooling it down? That means it's operating above the design (thermostat) temperature and as you push it harder in hotter temps it will run hotter yet.
Never mind, haha. Come to think of it, I've seen several fuel gauges that change as the temp warms up, the battery gets charged up or whatever it is changes besides the fuel level. Could be the voltage drop from the heater fan "cools down" the gauge rather than the coolant?
By turning on the heater you are almost doubling the cooling capacity, why wouldn't it cool it down? I just picked up a new sender from my CAT dealer and it is different than the one on it, I verified with the parts guy he had given me the correct one and he had. I will report my findings later.....JUNKMAN
Part Number of new sensor..?
I don't have the new sender with me. I only had a few free minutes today to work on it and I soon realized that the sender I thought was the temp sender is not it! I second guessed myself and I brought the engine up to temp and disconnected the wire. The gauge stayed put. I have no clue what the sender is, it is on the cylinder head right next to the water pump. I need to find a diagram of the temp senders location. I looked around the engine briefly but I will be darned if I can see it. If anyone can help, the serial/arrangement number is 3yw03189. Sent from my iPad using Tapatalk
Shouldn't be a problem. I'll post something tomorrow regarding the coolant temp sender. Tell me what Part Number you actually bought and I'll let you know what it is and where it fits.
Thank you Sent from my iPad using Tapatalk
Your temperature sender is listed as a Part Number 120-0667. According to the top diagram (can't delete the bottom one) it's Item #8 and it appears to mount somewhere just above the alternator, or at least that's how it seems to me. It should have a single wire connecting to it, that wire should be marked 447 and coloured orange.
Thanks Nige, looks like it's back off with the shroud and fan blade!!!! YA!
T Sent from my iPhone using Tapatalk
There is nothing wrong with anything here. Stop worring and Run the excavator man .....
Wow, thought this thread was dead...couldn't agree with you more pafarmer. Maybe all this keyboard typing is heating up the excavator...