I may have to replace the bearings and was wondering if this can be done without removing the engine. I know on some vehicles you can just remove the oil pan and change them, has anybody done this on a discoII ?

 

rod bearings? main bearings?

 

if its rods then you can service them in the truck, if its mains the motor needs to come out. so if rods, make sure to mic the rod journals and assure they are within spec. Either way if you know you need any bottom end bearings, the motor out of the truck and crank at the machine shop, if you spun a bearing have the rods done as well.

should have asked why do you need bearings?

 

I am not sure if it needs them yet, I am just going thru all the possible scenarios at this point. I will find out tonight. I replaced the head gaskets and when I started it up I had a #5 open injector code. Ran for about 10 minutes with motor flush to clean the engine from the leaking coolant. Idled a little rough but other wise sounded good. Changed the oil and filter again then started engine for 2-3 minutes again to see if I still had the same code. Pulled the upper intake off and saw that I didn't have the connector on all the way. Put the intake back on and started it up. Immediately there was a loud rapping noise in the engine.Rod bearing?, Dropped something down the intake?, Valve lash?. It did not have the knocking when I ran the engine with the #5 injector unplugged. What do you think?

 

ouch, there are small, round, hollow alignment pins between the two halves of the intake plenum, as i remember. i dont think its likely you picked up a rod knock with the scenerio you just described with having a dead injector. me personally, i would backtrack your work and even take the lower intake off and get a look down into the intake track. have you driven the truck like this?

 

No, I shut it off immediately. Being late last night I left it until tonight to tackle again. As a first step I am going to put a scope down the intake runners to see if I find anything. The scope I have isn't small enough to go in the spark plug openings to check inside the cylinder but I thought I would at least try putting a magnetic end in to see I if pick up anything If I don't see anything in the intake.

 

good call. i hope for your sake you do not see anything. let us know how it looks.

 

After scoping the intake runners and not finding any foreign objects we pulled off the valve covers to check for valve lash. A mechanic friend that was helping me said that after flushing the engine and draining the oil again it was possible that one of the hydraulic lifters may have lost its pressure. Turned out to be the problem. Put everything back together ran the engine for 15-20 seconds to build up the pressure and the noise went away and has not returned. I have been driving it for 3 days now and it sounds and runs better than new.