Some type of knock

[Motoman991]

This car is starting to **** me off. Last friday I was on my way home at a stop sign. I give it some gas to take off and the car starts studdering and running like shit. When I get back to my house I pop the hood then start the car. It sounded like someone was taking a hammer and hitting the block. It was for sure metal on metal contact. I have no clue what it could be. I know its coming from one of the cylinders closest to the firewall. I have already got the intake off and the valve cover and haven't seen anything that looks messed up.
Anybody have any suggestions on what the problem could be?

 

[Mr Anonymous]

My first recommendation for any kind of knocking noise you can't track down is to run the engine with the assy belt off, Bad bearings can make an awful racket, and I've heard bad alternator bearings that sounded like rod knock.

There could be something inside a cylinder, you might want to see about borrowing a boroscope to take a look.

You could also drain and strain the oil to see if there's any signs of metal in it.

 

[Motoman991]

I checked the compression is the back 4 cylinders. One was at 150psi and the other 3 were over 200. The spark plug on the 150psi cylinders looked as if something was hitting it and forced the metal to almost touch the electrode and it also has a few good dings in it.

I also squirted some oil into the the bad cylinder and checked the compression a few more times. The first check went from 150 to 175. The next time took it upto 200. Then the time after that it went down to 175.

I am guessing something happened with the piston rings since putting oil into the cylinder made the compression go up.

 

[stephen newberg]

Are the cam sprockets welded?

pax, smn

 

[Motoman991]

Yes, they are welded. None of the welds are broke either.

Have any of you guys ever taken apart their engine before?
And if so did you take the engine out of th ar first?

 

[lancSHO]

Most usually remove the front subframe with the drivetrain still intact out the bottom of the car.

 

[Motoman991]

Most usually remove the front subframe with the drivetrain still intact out the bottom of the car.

Thats what I was thinking. This car is making my ass go broke.