Scalpel

iTrader: (4)

He had a stacked rod bearing before and had a new rod, crank and bearings put in. This is the noise we hear now and it's getting worse:

http://home.insightbb.com/~l.proctor1/MOV00012.MPG

Sounds like a rod <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
It doesn't really do it much when it's in neutral but when under a load it does.

<small>[ October 17, 2002, 04:17 PM: Message edited by: NastyC5 ]</small>

Jasin98Z

The guy who fixed it the first time came over and listned he said it sounded like a lifter? is it possiable for that to be a lifter? it sounds ALOT worse than a lifter, but at idle its fine and dandy, but if you put the ebrake on put it in 1st
(6spd) and load the engine it sounds horriable..

Dane 98 Bird

Lifters tapping don't sound anything like that!
Dane

Tom99SS

iTrader: (2)

Does the knock lessen or get louder as the car warms up. Cold knock (piston slap) is common on start up(from what I have heard and experienced) but goes away after the car warms up.

Just curious.

NataSS Inc

iTrader: (9)

I wouldnt drive that thing ANYWHERE other than to someplace you can pull and inspect the internals of that motor. That is definatly NOT piston slap. If it was it would be doing it at an idle on a cold motor not a warm one and it also starts slapping almost immediatly after startup. That sounds like a bad bearing that is getting ready to go **** up on you. It sounds like its coming from the bottom side of the motor (see rolling assy). If it was a rod, it would more than likely be more of a WHACK than a knock. But no matter what it is I would tear the thing down before you end up replacing it.

Scalpel

iTrader: (4)

This is not a lifter tap, at all. I know what a lifter tap sounds like. And I heard with my own ears Jason say when he was on the phone with the mechanic, "No, it doesn't sound like a bad lifter it's a loud knock."

This is a bottom end problem. I think the bearings are going out, again.

It is definately NOT piston slap. Piston slap goes away once the car is warmed up and it is no where near this loud.

StevieZ

iTrader: (3)

sounds like a C rod to me.

Jasin98Z

Yeh, i got off the phone with the ppl who did the work on it, bearings crank etc.. they told me last nite it was a lifter, NastyC5 AlexP, and me kinda looked at each other, I called this morning they told me that it sounded like Piston slap, but it doesnt do it at idle, and it actually get LOUDER as the car warms, when you put a load on it, it knocks, when he drove away last nite (the mechanic dude took it home) AlexP and i could hear it from 30feet away. I didnt wanna drive it, they told me however since they didnt replace the pistons (but they took them out and OHMED the blokc) that i was responsiable for the noise and needed to buy new pistons, i told then it never did that before you worked on it, we got into a big arguement n such.. i always though piston slap was heard at idle and went away when the car warms up, this is opposite, cant hear it at idle and gets louder as car warms.. Also if you listen to that video closely you can actually hear it faintly at idle.. btw it took them 3 freakin months to give me my ride back after the stacked rod bearings thats 480 working hours, and it pays uhm 22hours.. Also that knocking is comeing from the SAME side and the rod that stacked the bearings,, #6

JAY4SPEED

Hi, this is my first post here....

Listen to the speed of the knock is it consistant with every crank revolution? Or is it half the time of the crank along with valvtrain rotation? Valvetrain spins at half crank speed. This helps to determine upper and lower knocks. Valvetrains usually have a light ticking noise and will almost never change with engine load conditions with the exception of timing chains. On the other hand lower reciprocating assemblies have a deeper and more solid knock. Mains knock under load. Rods knock on deceleration from a rev as no load (pressure) is pushing down on the piston holding it against the crank and rod allowing it to knock. If you suspect a rod knock you can further narrow it down even to the cylinder. All you have to do is cancel the cylinders one at a time by pulling plug wires one at a time and listen for the knock to get louder. When you cancel the cylinder, you are taking pressure of combustion off the piston and rod allowing it to "float" and the knock will be louder. Basically take one plug wire off at a time and listen for a change in the sound to become a lot louder, then plug hte wire back on and move to the next cylinder. Same goes with flywheel knock, you rev it up and as soon as it comes down from the rev the knock comes in. I've also heard this on 2 piece crank balancers. Mains knock when the crank is under stress as in engine load {torque braking}. The crank flexes considerably under load allowing it to move up and down in the bearings more making the sound more pronounced.

Hope this can help you narrow it down.

PS stupid question but they did put a new pilot bearing in that new crank for your M6 didnt they?

Jay

MelloYellow

Not a lifter. Rod, Crank, spun bearing, etc.

Jasin98Z

Last nite the car set 2 multiple misfire codes, and a bank 1 lean condition code, cant reemember the exact code #'s somthing like P0133 and a P0171 could the misfires be account for because of the other code?