This is in nuetral and with the front tires off the ground in gear. Thought about looping the trans lines together temporarily to see if that would bring the engine temp down. Dont want to burn up trans. I have not ruled out trying that.

You said earlier that it takes longer for it to overheat at idle. Is this in gear or nuetral? Just a thought for a test- disconnecting the trans lines at the radiator & piping them together teporarily to see how the temp of the engine repsonds

I' ve thought about putting an external trans. cooler. But my opinon and my service manger are totally different, on that suggeston right now. Combustion test has been tested on coolant system and it was negative. Rpm's at full throttle in netural are 3100 rpm's, In reverse and forward with brake held at full throttle is 1650 rpm's.

I was discussing this situation with a collegue which had the same issue. Their solution was a custom oversized (3 row) radiator & they also installed an external trans cooler. They've been using the truck without issue ever since-

Hi Greg;
Having expierenced the issue from the time this series and model was introduced in 1997 to the last production in 2004. The timing you have set is correct for the fuel supply and engine family. Do you have the fan belt deflection set at 0.43 to 0.51? Are the plugs being used BPR4ES and gapped at 0.035? Is the distributor's air gap at 0.018? Is the engine's max full load speed at 2300-2600 RPM and the no load speed at 2800-3000 RPM? Is the full load fast idle control adjusted correctly and is it functioning correctly? Are the LPG components OEM UL rated as per factory bulletin of Apr 24,1998? With the air cleaner filter installed has the power adjustment been made properly? With Impco system is the secondary spring correct and is the air valve pressure for idle and full speed correct? Has the engine been checked for exhaust gases in the coolant?

just tell us how many RPMs you get at wide open throttle in neutral, then with the trucks brakes locked and in forward or reverse.

Exhaust system was replaced on this unit also, muffler had a hole in it blowing exhaust on radiator. while counterweight was off, radiator was blown out. Unit has been run without thermostat and the same problem exsist. Fan is on correctly and at the right angle. Temp is being checked with a mech. gauge. Unit has been drove without using the the paper roll clamp or the inching pedal. It does take longer for it to overheat at an idle. Timming is set at 8 degrees @ 700 rpm's. I have just about ruled out that this problem is comming from the engine. The transmission has only been serviced. I did find some rather large metal chewed up shims in the tranny strainer. I will have to get the pressure readings on the trans. I would like to at least rule out one of the two.

yep, edward has a good point
if the trans is heating up just as fast as the engine the heat transfer could be an issue if the tranny is the problem.
being they are connected together the heat could transfer through the tranny into the engine.....
though sometimes its hard to distinguish which one is the problem though. maybe you could get some heat indicator strips and stick one on each component to see which one starts showing indications of overheating while checking pressures

checking the tranny is a good idea so you can either find the problem or rule it out all together :o)

let me jump in with what I think this problem is.
does this unit "load up" when going up a hill or ramp, but idles well?
since you note the 230degree temp is in the transmission, also, and only after a less than 1 hour run, I think there is every reason to expect you have a bad torque converter (broken stator or stator blades).
Have you taken trans pressure readings and done a transmission stall test while watching the engine RPMs?

Have you verified the temp with an auxillary mechanical guage? I'd also check exhaust to see if it's plugged.

Hi Greg;
You are involved with an issue none too common with the JO2, H25 engine, with the two speed transmission and LPG fuel system. Has the radiator been replaced with an OEM radiator that has been manufactured in the Turkish Republic? Has the fan spacer and mounting bolts been replaced from what was installed from the factory? Is the engine's fuel system tweeked in? Has the engine's timing been adjusted for the H25 with LPG fuel?

hi flow fans are used alot in applictions where ambiant heat is a problem, also in cotton mills etc.
its basically just a smaller pulley to make fan turn at a faster ratio for more air flow. Sometimes you get a special fan to accomodate for higher rpm rate.

Some things to ponder:

*is fan on correctly? (hopefully not on backwards)
*does hood need extra venting for better air flow?
*how does truck run with hood open? still run hot?
*if radiator is painted, remove the paint, paint acts like an
insulator and can make one run hotter than normal.
*hopefully you have blow truck off and its free from dirt and
dust (especially the engine and radiator area)

*you say a paperroll clamp? how does the truck run when you just drive it around without operating the clamp?

*are you running the correct mixture of coolant to water ratio?
a 50/50 mix is a must, DO NOT run pure coolant in the system.
*have you tried running without a thermostat to see how it
performs? does it still run hot? remove the thermostat, throw
it in a pot of boiling water and see if its opening. another way
to check is watch the water in the radiator and see if its
flowing when the engine is running. Generally when the
thermostat opens and closes you will get a rise and fall of the
coolant level. (ok you already did this so disreguard)

Of course BE CAREFUL because if it runs hot it
will run over and spew out everywhere when you least expect
it. Coolant burns are very painful and can be bad.

These are just a few things that come to mind while pondering your overheating issue. Good luck!

The high flow fan was suggested by nissan its an all metal fan. Fan shroud and fan spacer are present and in good condition. I think the radiator is three row design. I'll have to check on that. This unit is set up with a paper roll clamp attachment.

Greg when you mean high flow fan, are you meaning the fan designated for the platinum series (hint)? Is radiator 2 or 3 row design. Check if fan shroud and fan spacer is present. Also check for lean fuel mixture and recheck timing. Is the operator using it as a forkdozer? What application is the unit running? I know there is a long distance between rad and fan on these units.