Does this sound like a thrown rod?

Bob,

Do you have any way to record an audio clip and post a link to it?

Jeremy

Doesn't exactly sound like a connecting rod from your description. Could be a bad valve. B

Pull the plugs, Stick a finger over the hole and see if you feel compression on each cylinder. If you dropped a cylinder you won't find compression on at least one. Now to determine if you did throw a rod look into each spark plug hole and see if you can actually see the piston (haven't messed with a 2.2 much) moving. If they all seem to be moving then you may have dropped a valve, or a lifter may have failed.

Steve W.

I think if it's an actual thrown rod, 99% of the time the engine will absolutely not run. The rod and piston seperate from the crank and mash valves and/or the crank. I'd imagine if the engine was able to run, that it'd vibrate noticeably from being out of balance.

It's real hard to say what the problem could be without hearing it... If it's in the bottom end of the engine, you'd hear a noise every revolution. If it's in the top-end (valves, lifters, cam), it'd be at half the engine speed.

My guess from here would be something in the top end of the engine, like a dead lifter or bent pushrod. I don't think there's any other types of "issues" that would normally allow the engine to run without completely self destrucing.

-marc

Also, Any way to pull the code off the computer?

-marc

Usually a rod will knock TWICE per revolution

snip

My snowblower blew a rod last winter. It (some of it) exited just below the starter motor and landed in the snow, then melted it's way out of site. Most spectacular. B

Just finished the compression check. 1,2 and 3 cylinders are 190, #4 is

From what I've gathered on various boards I'm thinking the prob is actually with the timing chain. Possibly slipped a gear if the tensioner went bad? For all you experts out there.....sound like I'm on the right track?

Unfortunately its raining and I won't be able to dig into that until tomorrow.

Thanks again for everyones help.

Timing chain is the next step in this diagnosis. b

Wouldn't he have a pencil-sized object or a small dome about the size of a marble in his valve cover? Unless it went out the bottom. I know a Chevy will run with bent rods. I had a retard of a mechanic replace a thrown timing chain on my 307CUI and it took him 30 minutes to start it, but it started with 4 bent rods and 1 shattered. Not to mention bent valves.

~KJ~

When my 4.3 did this it was carbon buildup in the combustion chamber. The dealership let it warm up then with high RPM one guy poured about a half quart of transmittion fluid down the throttle body (don't let the engine die) to dissolve the carbon. Sure cured my thrown rod in a hurry. It may not work for you but I'd give it a try.

Jerry

Don't know about the transission fluid but I've used parts solvent already (not really recommended) and also poured Marvel Mystery Oil down the intake. The Mystery oil worked for me but the smoke coming out the exhaust is worth mentioning (as in it will smoke like a cheap cigar for about 10 miles. Some guys use ice water. The ice water works by thermally shocking the deposits and knocking them loose. Regardless of what you use, you've got to pour it in VERY SLOWLY. If you pour it too fast, the engine will hydraulic and could suffer some severe mechanical damage.