Overheating while only in 4Hi and 4Lo

So I have done a search for this and the only solution I found was to clean the radiator with simple green several times, which I have done. So, my truck is overheating every time I go off-roading. Driving normal on the streets and freeway is fine and no issues, but once I hit the trails my truck will start overheating where I have to turn on the heater for the temperature to go back down. It started when I took my truck on the Rubicon and 3/4 in it started overheating. During that time I thought I was just stressing the truck to much. Then I started taking the truck on easy trails and I was having the same issue right away. I took my tuck to the dealership and they said they could find nothing wrong and keep turning on the heater while off roading... like if this is normal... Does anyone know what is the solution for this?

 

I want to say I have the same experience. I can feel the heat from the vents when everything is off. But I've never look at my temp gauge when I'm roading

 

Idk about off roading the truck per say, however I can tell you that extracting engine heat from the heater core to keep it cool is a crutch, not a solution. Is your radiator full?

 

Can you be more precise about what you mean by “overheating”? Are you just looking at the temp gauge on the dash or are you observing other things?

 

Yeah that's not right. Obviously you should change the fluids that may have been affected. Have you done mud or water often ? I've heard of radiators getting clogged. People think they clean em out well but the ones that seriously play in mud or offroad with dusty trails spray the radiator from the back and top down with whatever dirt soaker or remover and have good results.

If you're wheelin in the desert there is a thread that has an aftermarket fan that is meant specifically for this reason. Ill see if I can find the thread if you're interested after exhausting other reasons.

Also just remembered maybe a faulty t stat

 

Is it overheating or simply running a bit hotter than during normal driving?

 

Pictures ??

 

I'd check to see what the ect pid shows while the gauge goes up and see if the fan comes on and make sure the temp goes down when the fan comes on. Depending on the milage I'd put a new thermostat in also.

 

My temps came up one time while four wheeling with a group. I was trail vehicle waiting for the group to clear some obstacles. I put the truck in neutral and gave it a little throttle to get some airflow across the radiators. Figured it was the torque converter getting hot from creeping. Has never happened while out in the desert or any other time.

 

I had the same issue with my 04 back when I first got it. Never overheated on the street, but offroading it would start to overheat and fast if it was a hot day out.

Problem ended up being the fan clutch, or lack of one in my case. Previous owner installed e-fans and they did a terrible job of cooling on the trail. I threw those out, got a stock fan clutch installed and haven't had an issue since (4 years ago now).

So in your case I would make sure the fan clutch is operating as it should. When you're driving around on the street you're usually pushing enough air through the grill to help cool the engine, unless you idle or sit in traffic a lot. But offroad that's not usually the case. Without a working fan clutch you will overheat quick in slow moving conditions.

Could be other issues but that's just my experience I'm tossing out there for one consideration.

 

Fan clutch.

 

One idea is a fan clutch.

 

Does it do it at extended periods of idle?
In traffic?
Or only in 4WD and on the trial?

I’d think it do it in 2WD if the conditions were the same.
This doesn’t “seem” right.

 

I'd want to test the fan clutch for sure.

Are you running a/c on the trails?

Is it auto or 6 speed?

 

radiator flush

how many miles on engine

what model year

 

Your engine is going to get hotter driving slowly in hot weather. Going to lower gears and getting engine rpm up may help.

 

Yeah, it’s full. It’s currently at the dealership and they are having a hard time figuring it out also.

The temp gauge on the dash goes all the way to the right where the red H is at be where it can’t go no more and then a warning on the dash comes up saying “Temperature to high. Shit is about to explode”

I have took my truck through mud a couple of times and through rivers and creeks also. I thought the radiator was just dirty also and I cleaned it with a hose and simple green pretty good. Didn’t clean it multiple times but tried to clean it the best I can the one time. But last weekend it started doing the same thing again...

Overheating where if I kept going I would blow up the engine.

I’ll try and get pictures of the gauge next time...

I have 50,000 miles on it... I think the fan stays on all the time because it’s fixed in the pulley in front of the engine.

So far both dealerships checked the fan clutch and they both said it’s fine and working. This last mechanic went and compared my fan clutch to a new Tacoma and they act the same. Kind of wish it’s the fan clutch so they can replace and fix my solution. Lol.

I wish.

That’s would be a good idea. I agree also but the mechanics don’t think so.

No, it’s fine when I drive it in an hour of bumper to bumper traffic here in the Bay Area. I only notice the temperature going high when I am in 4wd but never 2wd.

Yep, I will A/C until the temp goes up on the trail and say oh shit, it’s getting hot and turn off the A/C and blast the heater. Then I tried it with no A/C and have cabin temperature to 75 degrees and it would still overheat. The only solution so far is running the heater.

It’s a 2017 and has 50,000 miles. The mechanic was telling me the radiator guild is good for 90,000 miles. Which is crazy.

Maybe, but I have done it where the outside air is only 75-80 degrees at 5000 ft elevation.

 

Have you or anybody else modified the fan shroud? When the engine overheated did you try and spin the fan by hand? It should not spin.

 

Radiator might have gunk between the fins from your mud event.

Anything between the AC condenser and radiator?

The fan has a hydraulic clutch. When it is cool, the fan will spin when the "pulley" is stationary. It should lock up when hot. Check to see if it locks up when overheating.

Edit: might check if all the air is bled out of the coolant system.

 

this used to happen with hi mileage cars

heads would get crusty from OLD coagulated coolant

depositing residual crud thru out the engine

degrading the cooling

remedy= flush............serious flushing

sometime what was a reverse flush from those that knew

no less it usually mean U had to pressure check the the radiator cap......cheap replacement anyways

most o the time it required a thermostat.............pull the old have a look

if U see crusty old thermostat

U will probably need a water pump

how many total miles is on this engine........how many miles ?????