If it was actually overheating it should be triggering a fault code of just 1's and not 3's

Overheating usually takes a few minutes if the WP drive belt has failed.

You can use a thermal gun to see what the temps are at various places.....They usually have a 180 or 190 T-stat in them and the head will read something close to that after it runs a while.

If the coolant sensor is bad or can't read correct due to corrosion built up around the sensor inside, it also should be triggering a fault code of 1's....

Read the secondary code and see what that is after it shuts down and is flashing 3's

Push stop one time and see what you get after doing that...It has to be flashing 3's before you push stop once.....

quote:

Originally posted by SCDIV1:
If it was actually overheating it should be triggering a fault code of just 1's and not 3's

Overheating usually takes a few minutes if the WP drive belt has failed.

You can use a thermal gun to see what the temps are at various places.....They usually have a 180 or 190 T-stat in them and the head will read something close to that after it runs a while.

If the coolant sensor is bad or can't read correct due to corrosion built up around the sensor inside, it also should be triggering a fault code of 1's....

Read the secondary code and see what that is after it shuts down and is flashing 3's

Push stop one time and see what you get after doing that...It has to be flashing 3's before you push stop once.....

OK I'll read the code again tonight. I'm pushing the stop button once after the initial set of flashes and I swear it looks like its flashing 3 times before it pauses to repeat.

I've got a temp gun will check it in spots as well. Top cover is still off.

Already changed New belt, New Stat, New Sensor, and flushed system with no help. What are chances radiator is plugged?

I’ve never seen a radiator or coolant flow blocked so bad it caused what you’re experiencing.
I did have one that would overheat on a very hot day from a radiator that appeared to have a lot of deposits from DexCool. White stuff visible and it was an original all metal radiator. Newer ones are plastic and aluminum.
The controller inside the unit can lie and anything is possible but the fault code is one of the few things they have to diagnose a problem.

Read that code again and try the 3 push stop also when it’s not flashing 3’s

I’ve seen some bizarre things with these and it’s always the controller/inverter section

Its definitely all 3's no matter when I push the stop switch. While flashing or at a pause. This is a 2004 with the metal radiator.

It will not show you the actual fault code for why it shuts down so diagnosis becomes more difficult.

It takes at least 5 minutes to get hot enough to shut down from overheating.

Shoot the back of the head when it’s running with a temp gun.

My opinion is it’s something other than overheating but that’s just an educated guess.

How many hours on it and what kind of shape is it in ?

I’ve seen a number of control/inverter failures on units from that era.

The fact that it will not show the 2 number second fault code is not a good sign.

They can and almost always get an air pocket in the head if you drained it to change the parts you changed. I always filled the block right at the t-stat housing than put the stat in. Run it with the hose with cap up and open till it drops and quickly add more coolant.

This message has been edited. Last edited by: SCDIV1,

Only 3000hrs, and overall in really good shape, I think. Pulled the radiator out tonight to have it checked out. Will put temp gun on it when back together.

Invertor something I can take out and send off someplace to be checked out? I'm about ready to pull the plug and take it to Cummins unfortunately.

One thing I forgot to mention...

You can't run the machine with the cover off or it will overheat....

The covers have to be in place for the airflow to work as it was designed to....No air flow thru the radiator..

I run a machine with the top cover loose and can lift it up to shoot the temp but cannot leave it off...

Any opening and a lot of airflow is lost......

ALL Onan's are designed this way...compartment run is what it's called....


Flight systems in PA offers a service to fix those inverters.....$1000.....New you'd pay $2500 or more if you could find one

The inverter control section is all a sealed unit mounted under the one end.....Takes quite a bit of work to remove/replace it....

quote:

Originally posted by SCDIV1:
One thing I forgot to mention...

You can't run the machine with the cover off or it will overheat....

The covers have to be in place for the airflow to work as it was designed to....No air flow thru the radiator..

I run a machine with the top cover loose and can lift it up to shoot the temp but cannot leave it off...

Any opening and a lot of airflow is lost......

ALL Onan's are designed this way...compartment run is what it's called....

someone mentioned that on a RV forumn but didn't think it was true. I'll give it a try when radiator is back in. Thanks for all the help.

It is 100% true and the Kubota engine in your machine is a PITA to get full of coolant and no air pockets....

The air flow comes from the fan on the back of the engine and it has a very strong air flow across the radiator but only with the machine all covered and not blocked where the hot air exhausts or the cool air comes in...that can be blocked with a garbage bag sucked up in there

Well radiator was 60% blocked with white chalky crystals that wouldnt flush out from the radiator shop. Ordered a new one, will be in tomorrow. Fingers crossed between that, not having the top cover on, and maybe some air in system all will be good this time tomorrow evening

That while stuff may be from Dex Cool and the same issue as one I had that ran too hot in very warm conditions...I always used regular green A/F


The new radiator I installed ran 20-30 degrees cooler....

Getting it full as I said is not easy.....Pull the fill hose up and out as high as you can get it where the cap goes.....and once it's running and the t-stat opens.....get more coolant in there....

quote:

Originally posted by SCDIV1:
That while stuff may be from Dex Cool and the same issue as one I had that ran too hot in very warm conditions...I always used regular green A/F


The new radiator I installed ran 20-30 degrees cooler....

Getting it full as I said is not easy.....Pull the fill hose up and out as high as you can get it where the cap goes.....and once it's running and the t-stat opens.....get more coolant in there....

Well with new Aluminum radiator and radiator cap its ran for 1 hour with both AC's on and top cover on. Head temp was 185 after 1st 30 minutes and radiator was 145.

Sounds like it's fixed...good deal...

This was a good example of how lost someone can get working on one of these machines

Knowledge is power.....and experience is the best teacher....