Knock at start up?

Just like the title says, when I first start my car it has a noticeable knock sound until it warms up then I don't hear it. My car go through oil kinda bad. I just ordered an oil cap, I also know the seals on the turbo are no good. The car does not smoke or leak oil, but I will have to add a quart almost every other week. Any ideas?

 

[1941Galant]

Sounds like lifter tick to me. Have you installed the 3g listers yet?

 

It has 3g lifters, and it's a knock not a tick. I'm just wondering why it goes away when it warms up?

 

[AnotherNewb]

Almost sounds like a wrist pin. Once the aluminum in the piston warms up it expands and takes up the play.

 

[PreskitVR4]

Maybe it's got forged pistons and nobody told you /ubbthreads/images/graemlins/wink.gif

 

[AnotherNewb]

Try this... on a cold start when it knocks, try pulling plug wires one by one until the knock disappears. Narrows it down to the cylinder with the knock.

 

[PreskitVR4]

^^^^^^BTW, if it goes away it's prob a rod bearing issue; although I've never heard of that going away afta warmup.

 

[AnotherNewb]

Which is why I suggested a wrist pin. Aluminum expands more than steel or iron will at a lower temp.

 

I'll do the plug wires tonight. Lol no forged pistons.

 

[Olson]

Quoting PreskitVR4:
^^^^^^BTW, if it goes away it's prob a rod bearing issue; although I've never heard of that going away afta warmup.


Happened to me, now I'm rebuilding a motor with a spun bearing

 

[galant344]

what kind of pistons are in the car? could be wrist pin noise but i thought that doesn't go away when the engine is warm either? I know piston slap can go away when the engine warms up.

 

I was listening to my car at start up and noticed the sound seems to be in the back of the motor where the balance shafts are. Is it possible for a balance shaft to make a knocking sound?

 

[AnotherNewb]

Yes it is. I have a 6bolt motor in a talon right now that has a balance shaft knock, only when I got it it was really bad. Kinda laborous but you can pull the timing belt and connect a drill to the oil pump pulley, that's how I found mine.

 

Balance shaft will do that to you. I rebuild 2 bottom ends last season for what they thought was a rod knock. It was a spun bearing at the rear balance shaft that the bearing fell into the oil pan. pull the pan and front over off, and double check. A great time for a BSE kit.

 

Ehhh, I pulled the plug wire out of cylinder #4 and the knock stopped. /ubbthreads/images/graemlins/frown.gif That's no good...