knocking sound isolated to cylinder 7,by shorting out plug leads noise stopped when lead 7 was disconnected.big end bearing 1.8 thou clearance main bearing tested in two spots between 1.5 and 1.8 thou. clearance between piston and liner 1.5 thou......wrist pins show no excessive movement.all bearings look ok again no signs of failure.....motor re sleaved with top hat liners. it sounds like piston slap but clearance as taken 90 degrees to wrist pin sounds ok. like most pistons are not round as you would expect how much clearance should you have on the non bearing sides and if its to much would that cause them to rattle????? i am at my wits end trying to solve what would cause the rattle.should i replace the piston and hopefully that will cure the problem?? is this a common problem with 4.0 V8 ? any suggestions would be great.

 

No this is not common with Rover V8's.
Is the injector good?

 

i have tried and looked every where i think the noise seems to originate but not the injector what sound would that make if it was faulty?i might just replace the piston and hope for the best.i need the truck back on the road.maybe i will keep on looking???????

 

I get the same engine knock whenever I throw the car in reverse, its annoying. I gave up in trying to figure out what it was. I have a 97 D1 =\