8540 engine problem

[vulcain_2]

Hello

I am wondering what could be wrong in my 8540 because it is making some kind of knocking noise when engine is cold. I tried to loosen each injector pipe nut one after another and when last cylinder's injector is out of the game noise disappears. So I took this injector to the mechanic who tested it and said it was OK. Then I tried to push (through injector hole) the piston to see if there is play, I noticed nothing. When engine warms up noise almost completely disappears. Engine starts up easily, runs smoothly right from the start and doesn't smoke. Noise is can be clearly heard at idle (and it is quite loud) but at higher rpms it disappears.

Any ideas what could be wrong?
Thanks

 

[ixer0]

Hi,

The UR3 range had a few problems with the relief valve, for the engine oil pressure sticking. It would stick partly open which gave you very little oil pressure. The end result was big end bearing failure. Put a pressure gauge on the switch tapping. If it is low stop using the tractor as you'll cause more damage. Have you noticed the light coming on at tickover when it is hot ?
If it's not this, has it been overheated ? If it has the noise will be a siezed piston and rings.
Either way, if it's knocking you need to repair it before it makes your mind up for you !!

Mike

 

[vulcain_2]

Oil pressure light goes off about 1-2 sec after coldstart and at warm engine almost immediately after start up. I have not noticed the light to come on at hot or warm engine even at low idle. The time I have got this tractor it has never overheated. Of course I don't know what previous owner has done with it but it has got over 6000 hours on the hourmeter.

But I will check that oil pressure and then I'm thinking of dropping the oil sump.

 

[mikki69]

Could it be the exhaust or air intake valves ?
I remember my old Volvo had a similar problem and it turned out to be the valves but that was a Volvo so I dont know it is the same problem just a thought .

 

[vulcain_2]

Update to this problem

I dropped the pan and opened connecting rod bearing which was in very good condition, then I tried if there was play in piston pin, I found nothing.

After that I changed injector from 3rd cylinder to 4th but that made no difference in that noise. Then I noticed that someone had put different type of bolt to 4th cylinder's delivery valve on injection pump and when I tried the another nut it was almost loose.

So I rotated and adjusted delivery valve by ear and that loud knocking sound seems to be history. Maybe I take that pump to diesel specialist some day to fine tune it.