HELP! Cat C1.1 Diesel Engine losing ALL oil PSI, Water appearing in Diesel Filter and Overheats after Pump and Thermostat Replaced

[jomeza001]

I need help diagnosing this Scag Zero Turn Mower with a Diesel CAT C1.1 3 cyl Engine and a 72 in Deck

I have checked the blade spindles and all are spinning freely.

It's got three problems:

1) It fires up real quick and feels strong while cold. When Temp gauge reaches half it loses power. Then Temperature reaches the red zone so I have to shut it off but motor is very very weak.

i already have replaced water pump and Thermostat. Still temp gauge reaches the red zone.

What is causing to overheat??

2) Within 15 minutes of using it there is already water in the diesel Filter. I had to install a diesel water separator to be able to drain the water easily. So every time I have to stop the mower and drain the water. The Diesel I use to refill the tank is not contaminated with water. And I have drained and meticulously dried the inside of the diesel tank twice in the past. Still I'm getting the same issue.

What is causing the water problem?

3) When I fire up this mower the Oil PSI is perfect, gauge reads half way. However when the Mower gets warm the Oil PSI drops to 10-12 PSI. When the Engine gets real hot the Oil PSI drops to ZERO even if at Full Throttle. I have replaced the Oil PSI Sensor.

Why causes the Oil PSI to drop?


Thank you all in advance for your help.

 

[EFSM]

Is this a Shibaura built engine? I would guess it may have a blown head gasket. Are you getting pressure into the radiator?

 

[farminkarman]

I need help diagnosing this Scag Zero Turn Mower with a Diesel CAT C1.1 3 cyl Engine and a 72 in Deck

I have checked the blade spindles and all are spinning freely.

It's got three problems:

1) It fires up real quick and feels strong while cold. When Temp gauge reaches half it loses power. Then Temperature reaches the red zone so I have to shut it off but motor is very very weak.

i already have replaced water pump and Thermostat. Still temp gauge reaches the red zone.

What is causing to overheat??

2) Within 15 minutes of using it there is already water in the diesel Filter. I had to install a diesel water separator to be able to drain the water easily. So every time I have to stop the mower and drain the water. The Diesel I use to refill the tank is not contaminated with water. And I have drained and meticulously dried the inside of the diesel tank twice in the past. Still I'm getting the same issue.

What is causing the water problem?

3) When I fire up this mower the Oil PSI is perfect, gauge reads half way. However when the Mower gets warm the Oil PSI drops to 10-12 PSI. When the Engine gets real hot the Oil PSI drops to ZERO even if at Full Throttle. I have replaced the Oil PSI Sensor.

Why causes the Oil PSI to drop?


Thank you all in advance for your help.

I’m not familiar with that particular engine, but I would be suspicious of a couple things. As already mentioned, a blown head gasket would be one. As for the water in the fuel, the only thing that makes sense is you are getting coolant into the injection pump somehow. If water is getting in there, then the fuel return can carry that water back into your tank. Either way, I wouldn’t run that thing again before getting it fixed.

 

[64poncho]

Is this a Shibaura built engine?

Engine is a Shibaura. To check for a blown head gasket, 1- pull thermostat, leave elbow off, 2- fill coolant to top of thermostat housing. Remove water pump belt. Start engine, let idle. If gasket is leaking you’ll get bubbles coming out of the housing.
Don’t know how water is getting in fuel, as the fuel system is not in contact with coolant unless it has a fuel cooler/ heater.

 

[Coupe]

Quick way to check for blown head gasket is warm it up and take radiator cap off.
You will possibly see bubbles coming up or if it is badly blown there is often
an oily film and inside of cap will be oily. As one of the guys said don't run it to much till fixed.
Thee oil pressure is possibly dropping because if it is getting as hot as you say the oil will be
thinning down possibly like water and the pressure will drop. As for the water getting into the petrol never heard
of that before.

 

[64poncho]

@jomeza001
Make any progress with the problems you are having with the Skag Tractor?