Hi all i have a customer with a high hrs WA450 with the 6D125 engine in it, supposedly the engine has been rebuilt by another party at some point, the unit is hard starting, draining fuel pressure off and needs priming after sitting, the engine oil is heavily diluted by diesel, large amounts of white smoke at startup and under load, also noticed diesel leaking from the exhaust manifold after startup. Ive not played with one of these engines before but im assuming its an injector failure?? Biggest problem i have is the machine is 300KM away up bush so i need to be prepared for all outcomes. Anything i should be on the look out for or any specific testing i can do? Plan was to go pull injectors for testing thanks
Just for shirts and giggles check pump timing and compression before and after a shot of oil. If all that checks out pull the whole fuel system.
You haven't mentioned the Dash number, serial number, year of manufacture or hours of operation. I'd say if it is one of the mechanical engines the injectors is where I would start. If it is one of the digital engines, well I'm a little too old to be able to say. I just haven't work on any of those.
yeah sorry the details are slim ive not actually seen the machine relyimng on the customer to relay it to me, it is mechanical though and the fuel pump has an external coupling drive so it cant be leaking past the front seal causing the dilution
Just the fact that it is hard starting, is going to dilute the oil to a degree, with a high hour machine. I know when I have trouble starting my backhoe and it turns over 50 times without popping off, there will be some diesel in the oil after. only has 7600 hours on it. lol
All the mechanical pumps are about the same then. There are match marks on the coupler and pump. Line up the match marks there and then check the degrees on the balancer on the front of the crank. It is possible to get fuel dilution from the pump as it gets its lube oil from the engine. There is a supply line and a drain line attached to the pump. I all my years working on Komatsu diesels, I haven't seen one unit that was found to be leaking diesel from the pump into the engine oil. That doesn't mean it isn't possible. Generally the older Komatsu engines of that model were high enough compression and injection pressures that starting was never a problem. They have grid heaters in the intake manifold by I've never seen anyone use them except on a very old engine with lots of blow by. The real issue I suspect will have something to do with the prior engine rebuilder and what skeletons were left in places that you can't see.
Does it have a fuel supply pump.. Running off the inj pump lobe.? Or bolted to the side of the engine..?? They have a seal in the back side that will go bad and leak fuel into the main inj pump and from there, back to the engine oil.
Those all had the combined hand priming pump and cam lobe unit bolted to the side of the injection pump.