8000 ford engine noise

[GSRFord]

I have a relative who bought an 8000 Ford out of a salvage yard.He got it running and it starts and runs good, but it has a tick in the top end. He checked valve clearances and they were good. He loosened injector lines on each cylinder until he eliminated the noise. Looking in the cylinder with a borescope showed nothing obviously wrong. I suggested it might be a wrist pin bushing, but I have not actually listened to it. If it is a bushing, is that something that needs immediate attention, or will it be ok to run this season? Thanks for any advice!

 

[Bern]

If it really is a wrist pin bushing that's making the noise, it won't last long. Certainly not the entire season. You'd be lucky to get a couple of days or even hours out of it. Wrist pin bushings usually make little to no noise at idle, and gets progressively worse as it's revved up. Same is true with rod bearings.

 

[GSRFord]

Thanks Bern, from what I gathered it is always there. Never goes away. I am going to try to go listen to it today and will report back.

 

[Emiel]

Injectors ok?

 

[GSRFord]

I haven't heard it, but he says it runs good, so I have no reason to suspect the injectors. Apparently doesn't miss.

 

[GSRFord]

Well I didn't get there today, so I will try to get there over the weekend. About an 1-1/2 hour drive. From what Bern said I would guess it is not a wrist pin. Can an injector make a ticking noise at all times? Anything else I should look for?

 

[Emiel]

I was at a 7810 once with a knock which was due to a not good spraying injector.

Noises are very difficult to diagnose on a distance.

 

[Bern]

Well I didn't get there today, so I will try to get there over the weekend. About an 1-1/2 hour drive. From what Bern said I would guess it is not a wrist pin. Can an injector make a ticking noise at all times? Anything else I should look for?

If you think the problem might be an injector, swap it with one from another cylinder and see if the problem follows you to that hole.

 

[GSRFord]

I got over to listen to the tractor yesterday. It has a definite rap as you rev it up. My ears aren't what they used to be, so I really don't know what to say about it. It isn't your typical diesel " noise" from just running. It does get louder as it is revved. They did swap injectors and the noise didn't follow the injector. I did notice the injector was not sealed up good in the noisy cylinder. Some fuel leaked each time it fired. I suggested he get a local traveling repair mechanic to come and listen to it. It doesn't miss and starts pretty easy. It was in the salvage yard for a reason, but who knows why. It had a rough life and lots of things are worn out and have been neglected. I think he bought a $3500 headache myself. The injection pump was full of rust and water, but they cleaned it out and it works. I just don't want to try to tell him what it is without really knowing, so I don't think I helped him much. I am by no means a diesel expert. Any other suggestions are welcome. Thanks to all for the advice so far.

 

[GSRFord]

A couple of follow up items. The noise is up high in the motor. I convinced him to get a oil pressure gauge and check the pressure. 50 degrees yesterday with 15-40 it had 50 psi at idle cold. He also told me later that when looking in the cylinders with the borescope, some showed hone marks and others none, so someone may have been in there trying to fix the noise before him? I have heard piston slap in gas engines, is that a possibility?

 

[Bern]

I'm going to say not likely on the piston slap. Those pistons are pretty tough.

If you're convinced the noise is up top, pull the rocker shaft off and inspect the underside of the rocker arms. Sometimes worn rockers can get grooves worn into the underside of them, creating excessive clearance. Said groove is narrower than a feeler gauge, so a typical adjustment won't get the clearance where it really needs to be. If that checks out, put a dial indicator on each pushrod and check cam lobe lift. You may have one or more worn cam lobes that have lost their opening and closing ramps, which could also cause noise.

 

[GSRFord]

Thanks Bern. I will check those things out. I have seen the grooves you are talking about in the rocker arms. Hadn't thought to check that. The noise just seems louder than I think loose valve clearance would be.