Overheating under load.

Roxor886

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I have almost 7,000 miles and it's overheated since day one under heavy load such as climping a steep hill at highway speed. It has overheated when everything was stock and after mods. I have the electric fan, egr delete, DF stage 2, cat delete and dual race exhaust. It's never an issue until i jump on the highway and have to stay in the throttle for a length of time. Is this a result of asking too much out of the little engine? Or am I overl ooking something? I should note the fan does kicking on and work at 210f.
 

Woodsman74881

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Just noticed you have electric fan. May not pull enough air. If possible you may lower the turn on point of fan.
 

Maz1222

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Had the same issue. DF stage 2 tune, EGR delete, electric fan and no cat. However I do not believe these were the only issue. I also added 4.88 gears, 33 inch tires, full cage, sidlers, front and rear bumpers, skid plates for engine, transmission, transfer case and fuel tank, windshield, winch, aluminum roof, aluminum roof rack and lights. The combination of increased HP, Torque and WEIGHT are causing the engine to work harder and produce more heat. My temps would run in the low 200 all the way to 229 or higher when pulling hills or trying to maintain 60 MPH. The stock radiator is single pass one row of 1” tubes. The fan was 900 CFM. What I did was change to a slightly larger all aluminum two pass radiator with two rows of 1” tubes and 2000 cfm Spal fan with custom shroud. Radiator installed with only very minor trimming of the top flange of the stock shroud to allow the radiator tanks room and some brackets welded to radiator. Radiator is also supported by full upper and lower saddles besides the side brackets. Stock hoses were reused with trimming. Radiator catch container was used in same position but I did need to a longer hose to connect to radiator. Both upper and lower supports and new fan shroud where attached to stock radiator shroud using self tapping screws in addition to side brackets. You do need to remove passenger side shroud support rod to remove radiator cap. Radiator is offset to passenger side slightly to allow room to access fuel filter due to larger radiator end tanks. Last picture is showing bottom of radiator and saddle support with lip that rests on stock radiator shroud. Yesterday in 95 degree heat and high humidity I pulled a long steep hill and attempted to maintain 60 MPH and only saw 212 degrees and this was with 249 IAT. As soon as I hit level ground, the engine went back to running around 195 which is now normal when running highway speeds (60 to 65 MPH). Next step will be to add an intercooler and I am confident that I will have no more cooling issues. Probably will also go to RX41 turbo in future. I worked with this place to figure out radiator size and mounting. I can not say enough good things about them. Ask for Chris.
Website
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txroadkill

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249 IAT, wow. And here I am worried about mine hitting 216 and trying to find ways to lower it without an intercooler. One thing to note, even with an intercooler your still going to see high IAT as it’s reading just off the turbo and not closer to the engine. To get a true temp your going to need to relocate that map sensor or install a second intake temp sensor after the intercooler.

hottest I’ve ever seen mine get to is about 200-203 after coming to a stop at a stop sign. Shortly after take off it quickly drops back down and settles in around 188-190. This is with a stage 1, 4.88s and 33s as well as lots of armor. Of course I’m on mostly flat ground and no long hard pulls. might be different but might not, I’m still running factory fan setup. thanks for sharing your setup.
 

Roxor886

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Had the same issue. DF stage 2 tune, EGR delete, electric fan and no cat. However I do not believe these were the only issue. I also added 4.88 gears, 33 inch tires, full cage, sidlers, front and rear bumpers, skid plates for engine, transmission, transfer case and fuel tank, windshield, winch, aluminum roof, aluminum roof rack and lights. The combination of increased HP, Torque and WEIGHT are causing the engine to work harder and produce more heat. My temps would run in the low 200 all the way to 229 or higher when pulling hills or trying to maintain 60 MPH. The stock radiator is single pass one row of 1” tubes. The fan was 900 CFM. What I did was change to a slightly larger all aluminum two pass radiator with two rows of 1” tubes and 2000 cfm Spal fan with custom shroud. Radiator installed with only very minor trimming of the top flange of the stock shroud to allow the radiator tanks room and some brackets welded to radiator. Radiator is also supported by full upper and lower saddles besides the side brackets. Stock hoses were reused with trimming. Radiator catch container was used in same position but I did need to a longer hose to connect to radiator. Both upper and lower supports and new fan shroud where attached to stock radiator shroud using self tapping screws in addition to side brackets. You do need to remove passenger side shroud support rod to remove radiator cap. Radiator is offset to passenger side slightly to allow room to access fuel filter due to larger radiator end tanks. Last picture is showing bottom of radiator and saddle support with lip that rests on stock radiator shroud. Yesterday in 95 degree heat and high humidity I pulled a long steep hill and attempted to maintain 60 MPH and only saw 212 degrees and this was with 249 IAT. As soon as I hit level ground, the engine went back to running around 195 which is now normal when running highway speeds (60 to 65 MPH). Next step will be to add an intercooler and I am confident that I will have no more cooling issues. Probably will also go to RX41 turbo in future. I worked with this place to figure out radiator size and mounting. I can not say enough good things about them. Ask for Chris.
Website
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You hit the nail on the head i believe! I was leaning towards a larger radiator next step. You have confirmed my suspictions with a great write up! I appreciate all the pictures as well.
 

Colderweather86

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I have almost 7,000 miles and it's overheated since day one under heavy load such as climping a steep hill at highway speed. It has overheated when everything was stock and after mods. I have the electric fan, egr delete, DF stage 2, cat delete and dual race exhaust. It's never an issue until i jump on the highway and have to stay in the throttle for a length of time. Is this a result of asking too much out of the little engine? Or am I overl ooking something? I should note the fan does kicking on and work at 210f.
Being that it has overheated since day 1 stock, I'd say you have an issue other than load. Maybe thermostat not opening all the way, or a pinched core.
 

AZROX

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Unfortunately, the Roxor has only an over temp (coolant) warning light on the stock display / dash. I have not spent time looking into engine temperatures. So, this is a really interesting series of posts.

You guys on the forum who run scanners:
- did you install an additional temp sensor or are you using the one that feeds to over temp (coolant) warning light?
- Where is the stock temperature sensor (coolant) located?
 

Roxor886

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Unfortunately, the Roxor has only an over temp (coolant) warning light on the stock display / dash. I have not spent time looking into engine temperatures. So, this is a really interesting series of posts.

You guys on the forum who run scanners:
- did you install an additional temp sensor or are you using the one that feeds to over temp (coolant) warning light?
- Where is the stock temperature sensor (coolant) located?
I run a scanner and have a dash gauge.I tapped and threaded the sensor for the dash gauge to the thermostat housing.
 

txroadkill

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All my info comes from the scanguage. Boost, volts, intake air temp, water temp, plus others readings But those are the main ones I monitor
 

mickeybobs

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You might check your timing ...when retarted it causes heat ..and the smog gods love it... ..advancing it even 5 degrees makes a difference .
 

1BB

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I agree, since it has been a problem from day one, I'd start with the thermostat and check it for two things, one it is not installed backwards as that will cause your engine to heat up a lot more before it actually opens to allow flow through your radiator, and two, check the thermostat for proper operation at the correct temp.

Take your thermostat and push it open and stick a long string between the valve and the body and let it close on the string. Now take a pan of water and heat it up with a cooking thermometer in it and hang your thermostat in the water by the string and see exactly at what temp it opens and falls off the string.

Now you REALLY know at what temp it is opening and allowing coolant to flow to the radiator. It's a starting point to know what is truly going on in your cooling system, and a process of elimination without starting to replace parts that may still be hard to come by.

If you find that your thermostat isn't opening at the right temp, either too hot or too cold, you need to replace it. Surprisingly a thermostat that opens at a temp that's too cold, can cause an engine to heat up. The reason being, the thermostat also regulates how fast coolant flows through the radiator, and if it flows too fast, it doesn't spend enough time in the radiator to dissipate the heat, and the coolant carries that heat back into the engine and it starts getting hotter and hotter.

If your thermostat isn't installed correctly or not working properly, the radiator size and design means little, and after all the diesel engines they have built and mated to the radiator, they know what works and what doesn't, no matter what you have added on to the vehicle as far as weight or driving habits.

I want to say more, but I'm working on my posts lengths....how am I doing CJ2Rox...lol
 

SMF

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For those considering a mechanical water temp gauge, the aluminum DF water temp adapter offers a ready option. Its a direct screw in for the 12M (?) threads in the thermostat block and has a 5/8-18 UNF female end. Don't forget the included washer or to use sealant. Some temp probes such as that with the Auto Meter 5731 mechanical gauge, however, may be too long to fit into the DF adapter and still be able to reach/connect to the 3/8 NPT male compression nut on the line to the gauge. (The Auto Meter 5731 adapter included is too large for the DF adapter.) In this instance, use of an additional adapter is required to extend the depth to accommodate the probe. Auto Meter makes a brass adapter 2263, 5/8-18 UNF male to 3/8 NPT female. This combo arrangement works fine for Roxor. Threading dissimilar metals -- brass into aluminum -- can make a tight/sticky fit, but pipe dope helps. Then again, there's always the very slightly less accurate electrical gauge possibility.

Knowing the actual temp at which the thermostat opens on a stock 2018/19 MT Roxor vice one with added optional shroud would be an interesting stat. If someone has posted that info, pls advise. Thanks.
 

AZROX

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@SMF: Just curious. What is the difference between the temperature sensor already installed on the Roxor and an additional one (thermocouple) that can be read out on a mechanical gauge?
I think you posted quite some time ago about the different components. Great post. I looked into it and then decided to go the OBD scanner way.

The temperature sensor on the Roxor already puts data on the OBD bus. It can be read with a $36 plugin (plus a $20 OBD adapter) and an app on the phone. It alao can be read and displayed on a product calles Scangauge (cost around $150 plus the $20 adapter).

Is the idea of a mechanical temp sensor to not rely on Roxor electronics or to maybe have a redundant measurement?
 

SMF

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@SMF: Just curious. What is the difference between the temperature sensor already installed on the Roxor and an additional one (thermocouple) that can be read out on a mechanical gauge?
I think you posted quite some time ago about the different components. Great post. I looked into it and then decided to go the OBD scanner way.

The temperature sensor on the Roxor already puts data on the OBD bus. It can be read with a $36 plugin (plus a $20 OBD adapter) and an app on the phone. It alao can be read and displayed on a product calles Scangauge (cost around $150 plus the $20 adapter).

Is the idea of a mechanical temp sensor to not rely on Roxor electronics or to maybe have a redundant measurement?
I may have weighed in on that thread, but don't think it was me. Still, yours are good and fair questions. Sounds like you made a wise choice for your situation. From what I know, the Scangauge is a faster and more comprehensive option, tapping metrics already available, generally offering more data for the money. It does make adding a mechanical temp sensor or others somewhat redundant. Mechanical gauge simplicity, lack of reliance on electronics and the redundancy consideration, however, may argue in favor of them being less "vulnerable." Then again, in Roxor's case, if there are glitches with the electronics we've probably got far bigger problems than not having an independent back-up gauge. For some Roxor aficianados, it may all be mainly a matter of style (regardless of Scangauge practicality, economy, accuracy or reliability). To some, mechanical gauges equal old timey, reasonably bulletproof and fits the cool dashboard look they're after -- you know, folks like me that might also prefer Roxor with a traditional speedo, manual wipers and a fuel gauge tied to a float and arrow that reads between empty and full (without those bars that supposedly represent around 2.5 gallons each), and otherwise a vehicle built to withstand a North Korean electromagnetic attack (jk).
 

AZROX

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Thanks for the feedback.

I searched for the post that described the mechanical temp gauge set up. WoodLot was the poster, July 2018.
That thread also went really fast to an electronic solution using the sensor already available OBD.
 

Roxor886

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Still fight the heating issue. I had DF go through the tune and verify timing. I have totally taken out the thermostat. Still at highway speeds pulling it will overhead. I have checked the flow from the pump and it looks fine. It is over 95f here with low humidity. I guess I need to spend the cash on a better radiator. I was hoping if I put it off long enough someone would have came out with an aftermarket rad.
 
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