D6T Getting Hot

[nicky 68a]

I’ve had a little experience with fly ash.
It sets hard in fins.It also acts as insulation to the sump.
My thoughts are a major clean up operation is needed.
All belly plates off and possibly nose cone as you simply won’t clean anything more that 50% of the radiator(and that’s the bits that don’t block up).

 

[Nige]

There speaks the voice of experience..............

 

[Mark S]

I bought an IR temp gun, what temps should I be looking for off those hoses into and out of the radiator?

 

[Nige]

Look for the difference between the two temperatures, not the temperatures themselves. This will give an indication of how well the radiator is cooling.

 

[Mark S]

The left inlet hose was around 135° and the outlet on the right was about 122°-125°. Both temps bounced a couple degrees but it is close.

 

[Nige]

The left inlet hose was around 135° and the outlet on the right was about 122°-125°. Both temps bounced a couple degrees but it is close.

Was that with the engine running at low idle.?

 

[Mark S]

Yes at low idle. Both the trans oil and engine oil were at the higher/thick tick mark, running hot, but not in the red. I ran the dozer until that point, idled down and checked the temps.

 

[Nige]

In that case I would say that the radiator cooling performance is borderline at best.
That style of radiator there should be an 18-20 Deg temperature drop between inlet and outlet, not the 10-12 Deg that you measured.

These temperature readings point to the outside of the radiator being nowhere near as clean as you think it is.
As Nicky68a pointed out above fly ash has a habit of bonding itself to metal surfaces. This may have happened in your case.

Have you closely inspected the fan blades for wear on the tips.? Can you post some photos.? That may provide another clue.

EDIT: Hang on a minute. You are talking 135 DegF inlet and 122-125 DegF outlet, right.?
That is waaaaay off what "Hot" should be on the gauge. I would imagine an inlet temp to the radiator somewhere around 190 DegF would be classed as hot. Something does not add up here.

 

[Nige]

Follow the lines from the radiator inlet (right side) back to the engine and you will find the thermostat (water temperature regulator) housing. Take the temp of that point and of the radiator inlet and compare the temperatures of those two points.
If you can run the engine coolant temp just up to the red on the gauge that would be good.

 

[Mark S]

Follow the lines from the radiator inlet (right side) back to the engine and you will find the thermostat (water temperature regulator) housing. Take the temp of that point and of the radiator inlet and compare the temperatures of those two points.
If you can run the engine coolant temp just up to the red on the gauge that would be good.

I see 230° on that housing.

 

[Nige]

That's more like it. So why I wonder would you only see 135 on the radiator inlet.?
I know you said before that you are on a tight schedule work-wise but do you have time to replace the water temperature regulator aka thermostat.?

 

[Mark S]

Is 230° ok? Does that point to that thermostat is faulty?

I have a week and a half to run it and then I have time to make repairs.

 

[Mark S]

The inlet I am taking temp of the hose. Should I take the temp of the radiator itself?

 

[Mark S]

I see 190° on the lower portion of the pipe that is leading to the water housing.

 

[Nige]

Is 230° ok? Does that point to that thermostat is faulty?

230 on the housing compared to 135 on the inlet hose (that's a good enough place to measure it) like you originally said would put the temp regulator under suspicion.
Even 230 vs 190 is suspicious. 230 at the housing vs something like 220 at the radiator inlet would be somewhat more "normal".
If you don't have time to get into the cooling system until you finish the current job then best continue as you have been switching between the dozer and the excavator. That's all I can suggest.

When you do finally get into it you may be up for changing (or at least disassemblnig) far more than just a thermostat.