MIGHTY z28

Well where do i start ?!

I pulled the old water pump off the car and installed a CSR electric pump , new wires and got rid of the p/s and a/c. We got the car hot a few times bleeding the coolant system but always shut it off.

I had to re-adjust my belt and once i did i let it idle to see if the belt was gonna slide off the pulley again. This is where it go's sour !

It devoloped a knock. Sounds as if it is under the valve cover but i pulled those and all seems to be intact. I let the car run and all the rockers seem fine but i still here the knock.

Oil pressure is good , no fluctuation at all and no smoke or nothing. I took it out and buzzed it around , i even jumped on it real hard(figure if its broke i'll put that motor to rest) and it was fine till about 4500rpms then it started cutting out real bad and blew some carbon colored smoked and smelled like solpher.

I had some friends listen to it and they agree'd it sounds like rockers but they seem fine. I don't know what else to do. I know the oil is old so i'm going to change that , but my question is , is the cutting out issue related to the knock u think , or is that something else ?

I did not put a cap or rotor or plugs in the car , so do u think that is my cutting out issue ?

I will admit i know nothing about these f-bodys but have built many other cars ! To my knowledge , if the oil pressure is good , oil is full , and there is no smoke , odds are that it is not a bottom end issue , or are these things totaly different ?

Before i took it apart it ran great , no issues , no cutting out , no nothing ! I'm at my wits end and this is driving me nuts. I have to figure this thing out , my wife will not allow me to get another toy any longer LOL !

There is no ENGINE light on or anything so i'm simply baffled. I know i'm asking for a miracle here , buy hey even if u have a suggestion or thought that will help me a bunch !

Thanks,
Dale

slowpoke96z28

iTrader: (2)

find someone with a tech 2 and do a cylinder power balance test. as you kill the cylinder at fault the noise will go away. also make sure you have the right plug wires in the right places.

MIGHTY z28

The wires are in thier proper place.

PunishedU

iTrader: (1)

Seeing as how the whole thing started with the pulling of the water pump, did any coolant hit the opti at all. I know that doesn't account for the knock but because it ran fine before the csr install, the opti could have taken some water. Then again, what do I know?

Hope this provides more help than I think it will.

MIGHTY z28

I'm positive water hit the opti. I just pulled all the rods and all are straight and rockers look good !

I think i'm gonna put a new cap on it and change rods and rockers and try it again.

ReD95LT1

iTrader: (2)

Thats not good that you are positive the water hit the opti!!!

MIGHTY z28

Do u think i need opti ?

slowpoke96z28

iTrader: (2)

Alot or a little. did you drain the coolant before doing the pump? you may have to take the cap and rotor off and make sure it is dry. being a 95, it should have the vacuum system plumbed through it, so not much water should gather and stay in there, but who knows?

TransAm6383

iTrader: (1)

optis dont KNOCK though..back to the problem at hand.. do you have headers? once i had a header gasket blow out on me..and it sounded like a knock..i could hear it with open headers(i have a HUGE cam too) it was a slow and steady KNOCK. when you rev the engine..does it start to knock really fast? could be a rod knock....

MIGHTY z28

Well i pulled the rods out and rolled them on glass and there is no wobble ! I do have headers and slight leak , but the knock speeds up w/the rpm's ! Grrrrrrrrrr ! I'm going to try freshening up the upper end w/newer stock stuff and putting a new cap and rotor on the car and see what happens. Change the oil aswell.

Dale

trans97am

I don't have headers but i've had the same problem with my stock exhaust manifolds. The bolt on the front drivers side likes to very slowly wiggle its way out of its home and when it does it makes an obnoxious knocking sound, and can get very loud as he said and as the rpm's shoot up, so does the knocking. A little lock-tite has helped and havent had the problem since, but i used to have to tighten the damn thing about once a month or more. I would definately check all the bolts from the exhaust manifold to the engine though...it's weird that it only starts now after you worked on it, but ya never know. Hope this has helped. Good luck man!

TransAm6383

iTrader: (1)

yeah...a rod knock..youd hear the knock when the rpms are coming down....if its a fairly slow knock try to find out which side you hear it coming from(i woulda bet my life it was coming from the valve covers) take that header off and take a look at the gasket....mine was burned through and thats what was causing the TAP...but its not as fast as a rod knock..rod knock is more like a drumroll...and youll hear it sounds almost like a metal hollow sound when the rpms drop. and you say you have a headerleak..thats probably the sound your hearing....take the gasket out and inspect it..its prolly burnt through..causing a tap no matter how tight you tighten them.

MIGHTY z28

Thanks guys.

U've been a great help.

TigerWoodsJr

A knock that sounds valvetrain but everything looks good makes me think lifter. My bolt on LT1 had the roller on the lifter get a chunk taken out of it, it then polished itself up while making a groove in the cam. I had just got datamaster to log the car and at 5k in 3rd gear it happened, starting showing knock, kinda inconsistant and when we pulled the intake and the lifters I found one was bad, so I had to replace the cam as well.

Not a fun idea, but its a thought, I might actually have a video kicking around of my motor before I took it apart.

slowpoke96z28

iTrader: (2)

yeah if the lifters are bad, you don't want to put new lifters on an old cam, so its a good reason for a cam swap.