Ok guys, I need a little help. On a 2003 Ram 5.7 4x4, I found it had dropped a valve seat and crushed piston # 5. No problem. I have ran into this several times. But this time, after replacing the #5 piston, I cranked the thing up and........knock,knock,knock.!!!!!! It's a HOLLOW KNOCKING SOUND. I pulled the oil pam and ck all rod bearings and main main bearings,( seemed ok). Turned the crankshaft, using a pull handle and socked, When #6 piston gets close to TDC, I can hear the knock.(moving the pull handle back and forth,). I'm thinking that maybe a piece of the valve seat went by the intake and got #6 Piston too. My question: IS THERE ANYTHING I NEED TO CHECK BEFOR REMOVING THE PASSANGE SIDE HEAD AND REPLACING #6 PISTON????
Thanks
Randaman
Auto.Tech. Instructor
30+years

 

If you have a bore scope, have a look inside number six, and see if anything obvious presents itself. I have had some small success with removing the spark plug on the cylinder in question, and if the piece is small enough, cranking the engine will blow it out. (disable fuel pump, or coils, or something, you do NOT want the engine to start. )

 

Good idea. I'm going to remove all spark plugs and crank the engine over this morning.( fingers crossed). Also: going to run a compression test on all cylinders before I start removing the heads. ( I'm working with the engine still in truck). Thx.!!

 

Did you have an overtemp? Since you're taking the head off, you may want to check them for flatness, .0508mm is flatness tolerance.

 

Guess what??!! In my GREAT KNOWLEDGE of 5.7's, My dumb a$$ put a standard piston in a bored hole.!!!! BRILLANT.!!!!!! I just ordered the 1.mm over piston. going to install it tomorrow. I'll let y'all know if I fixed it. My fault. I just didn't notice that someone before me had the block bored. Live and learn.!!!!!

 

You didn't measure the bore first.....?

 

nope. Should have.

 

Good job on figuring that out. I would have missed it too. Good luck buttoning her back up. Let us know how it works out.

 

Ok, I got the head repaired, put backed together and the truck is running good.! On to new problem #2! After the rebuild, 2003 Ram 5.7, 4x4, PROBLEM NOW: After the truck run awhile, 10,20 min, and when I come to idle, the oil pressure drops to zero and I get the (Ding) sound. touch the gas or just wait and oil pressure comes back up. (The oil pressure doesnt really drop to zero because the engine doesn't tick or knock,(and I have let it idle for 2min with zero on the oil gauge.( I replaced the oil sending unit and cleaned the oil pick-up tube.). Im thinking I am going to ck ground wires next and maybe the wires from the sending unit to the gauge. What do yall think???? I have seen where other Ram people have the same problem but, no one gives an answer.

 

Did you use original rod bearings?
First step would be to connect a good mechanical oil pressure gauge to confirm pressure at idle.