G333 & 3306 NATURAL GAS ENGINES Determining Cause Of Shutdown Caterpillar

Determining Cause Of Shutdown
1.1. High Water Temperature
2.1. Low Oil Pressure

Anytime an engine is shut down by its protective circuit, the cause must be determined. In some cases the cause will be obvious but often an investigation will have to be made. On installations with fault lights the fault is indicated. Under no circumstances should the engine be put back into service without determining and correcting the cause of shutdown.

High Water Temperature

Look for the obvious first.

1. Determine if there is water on the floor from spilled or leaking coolant.
2. Check the water temperature gauge for accuracy.

------ WARNING! ------

DO NOT remove the radiator cap of an overheated unit. The coolant is under pressure and relieving this pressure will cause the coolant to flash into steam. Serious burns and engine damage can result from the escaping coolant. Pressure in a radiator may be reduced by pouring warm water on the top tank to condense the steam.



NEVER add cold water to an overheated engine.

3. Check air flow through the radiator and water flow through the heat exchanger.
4. Check air temperature to radiator. Few radiators can adequately cool a fully loaded engine with 125°F (52°C) ambient air.
5. Check for recirculating air currents.
6. Check fan belts for proper tension.
7. See that engine room vents and louvers are open.
8. Check water flow.
9. Check water hoses for leaks. Check for collapsed hoses. Hoses have been known to peel off internally and restrict water flow.
10. Determine if flow valves are open.
11. Check water pump drive belts.
12. Check raw water flow to heat exchanger.
13. If the engine is overloaded, overheating can result.
14. Check engine timing.

Overheating can cause seals and gaskets to relax. If severe or prolonged overheating has occurred, have the engine checked by properly trained personnel.

Low Oil Pressure

Look for the obvious first.

1. Check the dipstick.
2. Check floor for oil from leaks.
3. To determine if low oil pressure was the cause of the shutdown, crank the engine with the fuel off. If unusual noises come from the engine, discontinue cranking. If oil pressure fails to build up, and no external leaks are found, the problem is probably internal.