Just curious....Id think not, but will a rod knock quiet down when the engine warms up?
Earlier this winter I started the car and had some noise that resembled either lifter noise, or a rod knock. When I blip the throttle and the revs settle back down its more prononced for a brief second or two.
I was trying to find the location of the knock and I found(makeshift stethascope) that its the loudest on the trans bell on the passenger side. I though it was a converter bolt, but found nothing wrong there.
I started thinking rod knock, and I tried to investigate this past weekend. Once the water temp hits around 140 or so...the noise is entirely gone. I kind of ruled out lifter/rocker noise because I can barely hear it through the valve cover, so Im back to trans, piston noise, or rod noise(but based on the location of the noise...trans or rod "seemed" mostly likely). Would you expect rod noise to go away with heat?
Greg, I've had a rod knock in one of my previous cars, so I've been through that before. There's a very simply and sure way to find out for certain whether it's a rod knock or not:
Get a pair of rubber gloves, and/or a pair of sparkplug boot pliers or atleast regular pliers with rubber coated handles. Start the engine up, and while it's running and making the knocking noise,(in your case, when it's stone cold) pull one of the sparkplug boots off to see if the knocking noise stops. If it does, then push the boot back onto the plug while the engine is still running, and the noise will immediately return as soon as you do (if it's a rod knock in that corresponding cylinder). If that doesn't eliminate the knock, then go to the next boot, and pull that one off and put it back on again with the engine running. Do this with all 8 of the boots one at a time. If it's a rod knock, you will immediately hear the difference by ear beyond any shaddow of doubt just as soon as you tug off the boot, and the noise will immediately return the second you push the boot back onto it's spark plug.
If you go through all 8 boots, and it doesn't change the knocking noise, then it isn't a rod bearing that's knocking, and you've ruled out that possibility. this is a simple and effective diagnosis procedure. If it's anything in the valvetrain, the noice will not stop regardless of which sparkplug boot(s) you remove.