I would put a reversable fan on or else just a suction fan.

OK, here goes......

The ambient to top tank is withing spec, Delta T of 47 deg. C (61 C allowed)

The top tank to bottom tank Delta T is within spec but close to the limit,
8 deg. C vs 9 deg. C suggesting the water flow might be a little low but still OK.

The thermostat should be a 7N208 as shown in my 4X parts manual. This is a 90 deg C unit when fully open and should open a minimum of 9.53mm.

A 82 deg, C unit is one of the options (part # 4L7615)

The color temperature indicating gauge should read 98.2 to 102.8 Deg. C when just touching the red.

The radiator pressure relief cap should open at 105kPa and must not leak at 82kPa.

The injection pump timing is within spec, assuming it was timed by correct method.

Hi Team,
just put this scan from a Special Instruction (SMHS7140) that covers use of the Cat 9S9102 Thermistor Thermometer Group to back what OM has posted above. It all agrees.

The top pipe temp. Robby has given us at 85#C would be close to the actual engine coolant temp. and thus indicates the unit is NOT overheating but , that the gauge is likely Reading Incorrectly.

We have enough data from Robby to loosely determine his machine's Ambient Capability even though he has not tested with a blocked open thermostat.
From memory we used to get a failed T/stat and block it open 7/16" by welding two 1/4" nuts on their sides to keep the T/stat open at a consistant rate.
The machine is run at steady load and readings taken until the system temperatures have stabilised. The 7/16" opening is the size of the opening at full movement of the T/stat in normal operation and so sets the coolant flow thru the system.
Readings are taken as indicated below.

Ambient Capability Test. From a Caterpillar Cooling System Audit Log Sheet scanned below.
Temp readings are taken at :-
T2 outlet to radiator.
T3 ambient temp.

To get the ambient capability:-
99#C - (T2-T3) to get the ambient capability of the system.

As an EXAMPLE ONLY if we Assumed Robby was using a Blocked Open T/stat to test his system then from this assumed data we would get :-

99-(85-38) = 99-(47) = 52#C Ambient Capability before overheat occurs.

In Theory, at this time, this means the system should be able to run, and not overheat, up to the Ambient Capability tested figure, ie, theoretical 52 Degrees Celcius.
Until a blocked open T/stat is used in Robby's machine the 52#C can not be considered accurate, but I feel would be close due to the 85#C reading at the top pipe.

Suggest Test Temperature Gauge Accuracy. OM has given the gauge "Red Area" start temps.

Cheers,
Eddie B.

Hi edb,
Wanted to see your comments, Thanks.

If it were mine I'd still check out the thermostat using this procedure:

Hi OM,
thanks for posting the chart, I do not recall seeing it before.

I see it lists a minimum opening dimension of 3/8" so that is why we blocked them open to 7/16"--also it was what Cat specified for the Ambient Cap. Test.

Also agree, a T/stat test would not go astray and would give peace of mind as to its capabilities.

Cheers,
Eddie B.

I would say that a machine putting out 82C water to the radiator in 38C ambient has no problems at all and the thermostat is not fully open, the thermostat could be 91C and with a pressurised system the temp could go over 100C before the water boils. Running temperatures in the 90's are quite normal. I have seen temperature gauges indicating well over 100C but still acceptable with a very high ambient and pressure in the cooling system..

"catsilver" wrote:

I would say that a machine putting out 82C water to the radiator in 38C ambient has no problems at all and the thermostat is not fully open, the thermostat could be 91C and with a pressurised system the temp could go over 100C before the water boils. Running temperatures in the 90's are quite normal. I have seen temperature gauges indicating well over 100C but still acceptable with a very high ambient and pressure in the cooling system..

Right......

Still one more hurdle....
This engine apparently has the variable power option which hydraulically controls fuel limits from a switch on the transmission based on "allowed" gear selection. (I don't know what gears are allowed).

Apparently there is an indicator light on the operator's console that indicates when the engine is operating in the high power range.

What is the status of this light when operating???

Old wrote:

Still one more hurdle....
This engine apparently has the variable power option which hydraulically controls fuel limits from a switch on the transmission based on "allowed" gear selection. (I don't know what gears are allowed).

Apparently there is an indicator light on the operator's console that indicates when the engine is operating in the high power range.

What is the status of this light when operating???[/Q


Hey Expert have you ever seen a D6D?


Bob

bluox;79635 wrote:

"Old wrote:

Still one more hurdle....
This engine apparently has the variable power option which hydraulically controls fuel limits from a switch on the transmission based on "allowed" gear selection. (I don't know what gears are allowed).

Apparently there is an indicator light on the operator's console that indicates when the engine is operating in the high power range.

What is the status of this light when operating???[/Q


Hey Expert have you ever seen a D6D?


Bob

The D6D in question is not a VHP (variable power 160 hp in 1st end 2nd gear and 216 hp in a 3-4-5-6 gear, but at fixed power, still 165 hp in all gears.
Only the d6d VHP have a indicator light.
Robby