Hello everybody. Please read the entire story I know its long but this is my daily driver and I am desperate for experienced advise. Before I get started explaining the problem I have a 2000 firebird 3800 gen II engine not the LS1. However troubleshooting and theory should be the same.

-Ok had a leaking lower intake manifold gasket. So removed the throttle body, alternator, tensioner bracket, upper intake, lower intake, valve covers (just to paint).

-AT THIS POINT I KNEW I HAD A MISSING BOLT!!! SMALL SENSOR BOLT THAT WAS ON THE UPPER INTAKE (black in color, about 1 inch long).

-Here I cleaned everything down wiped down with razor, acetone and even vacuumed. Still looking for that bolt.

-Couldn't find the bolt. So I assumed it was stuck somewhere outside the engine and put the engine back together. Started, the car was rough at first getting fuel pressure I assume. Then a metal on metal sound. LIKE THE BOLT WAS STILL INSIDE! Here I checked the order of the plug wires and I had one out of order so I swap those around making sure with the manual of firing order. Same sound on start up.

-So at this point I disassembled everything again and still could not find the bolt. However I did find a BENT PUSHROD back where the missing bolt was!

At this point the bolt can only be in either the oil pan or in the combustion chamber by my logic. So I am asking you guys were to go next.

Option #1: I can put a new $3 pushrod in and reassemble the engine, start to see if the racket is still there. If it sounds normal then the bolt or whatever has passed through one of two holes in the valley passed the camshaft (maybe here is where the bent pushrod could have come from) past the crankshaft and into the oil pan. Problem solved by removing oil pan.

Option #2: Or for about $100 I can take off the heads and make sure the object didn't somehow get around one of the two possible valves and enter the combustion chamber causing the bent pushrod. If the bolt isn't in the combustion chamber I assume its in the oil pan and reassemble everything, remove bolt via oil pan.


What do you guys think of my logic?

 

Pull the plugs and see if there is damage to a plug. If so, your done. Use a pencil magnet in the cylinders to see if you can find carnage. If you can borrow or rent a bore scope then that would be the next step. If you can air check that cylinder for leakage then do it. If you are ABSOLUTELY certain that the bolt isn't lodged in the cylinder or under a valve then do a compression check to see if one of cylinders are low. If not, you need to buy a lottery ticket. If you made it through all of that then it sounds like it is in the oil system.

 

The weird thing is we pulled all the plugs off the coil packs. Then flipped the switch to turn the engine over using the starter and couldn't hear anything abnormal. But just before that with all the plugs connected we tried and it sounded like all hell broke loose.

 

The intake and exhaust have different length pushrods. You probably already know this, but something to double check.

 

I've heard that about different engines. I'll have to check the length of my new one. Advance only had one length tho. I also got a snap on camera that I can look through the spark plug hole.

 

BTRW just to update this. If you are missing a bolt or something and fear it might be in the combustion chamber. Buy a loan a friends camera to stick down the spark plug hole. I found this after I reassembled and started my engine, only to hear it **** up my no 6 piston.

I stuck the camera in afterwards (I loaned it from a friend that just happened to have one that I didn't know of) and sure enough the piston is cracked in half and the bolt was sitting right there in the combustion chamber. Oh well makes me wanna finish my ls1 swap anyway.

 

My experienced advice would be to find a forum for V6 powertrains and go there.