After readjusting my valve lash yesterday i took it for a drive. It ran great then I was coming off the interstate and stopped at a light. The car almost died, starting ticking loudly, and the tach went nutz. I got it home barely and turned it off. I went out this morning and checked...the valves arent ticking and I even readjusted them 1/2 turn after they stop ticking. The ticking sounds like its in the front of the motor. The exhaust also sounds WIERD. WTF is up?

 

ttt

 

Sounds kind of like a plug wire fell off.

 

No No i checked all the obvious things like that...

Update....pulled every plugs and all are BLACK covered. something is wrong The car been driven maybe an hour and a half since the last plug check where they all looked perfect.

All the plugs look like this.

Another update cyclinder compression test results so far:
#1- dead 0 psi
#2-190psi
#3-182psi
#5-210psi
#7-190psi

So far thats all I got because I think im might have to remove my headers to get to the rest of the holes to do the test.

 

Hmm that might be a problem...

 

the dead cylinder sounds kinda like a cracked head to me, but that doesnt explain ALL of the plugs looking like that.

jacob

 

Yeah every plug looks like that. Just yesterday I had them out and they looked brand new.

 

do you have any mortal enemies?

there is a posibility that maybe there was a foriegn substance in your gas. im no expert but that seems to pretty much explain the F'ed up plugs and dead cylinder. it could have all happened at once. if thats the case, you may have to get new spark plugs, flush your whole fuel system, and on top of that replace a posibly cracked head or even worse the block itself.

for your sake, i hope im wrong and overreacting. i would suggest taking it to a shop. you could also call someone like chevy's tech line or something along those lines.

jacob

p.s. dont break in and start doing alot of work just because what i said may be true. like i said, im no expert. GOOD LUCK!!

 

Sounds like the drivers' side head is gonna have to come off at minimum. The problem will be obvious once it's off.
Either a bent/stuck valve or a hole in the piston would be my guess.

Pull radiator cap and start (cold) eng. See if coolant blows out. (cracked head)

If you have an air compressor, you could turn the eng to TDC (watching valves to verify compression stroke) for #1 cyl, rig-up a hose to blow air into the #1 spark plug hole.
With the air flowing in, check intake, exhaust, radiator and oil filler opening for a hissing sound. Shouldn't be too difficult to find where it's going.

Are the plugs a shinny black, or a dull black?
Oil=shinny fuel=dull

 

It looks more like Oil but its powdery so maybe its fuel im not sure. Also I cant start the motor now the headers are off. I took them out to do the compression check and Im not gonna put them back on unless the motor is salvagable...the ticking sounds like it coming from the crank to be honest. I thought about pulling the head to see whats up.

If there was a hole in the piston wouldnt there be ALOT of oil going through? Its not smoking when running but the exhaust sounds very very strange...i cant explain it but it sounds bad.

 

ttt

 

I'm sure you would be losing some oil, hard to say how much.
Since the cyl is not firing and you have headers, the cyl could be pumping a little oil out the exhaust, but it wouldn't get hot enough to burn.
If you have a cat, it would burn and make smoke; but if no cat, if probably wouldn't smoke much if at all.

When run (or even cranked) with valve covers off, do the #1 cyl valves look like they're working like the others?

Might find some clues in the #1 exhaust port and header tube since you have them off already.

Wouldn't hurt at this point to drain the oil and see what comes out.

 

Ill look at the headers and exhaust port. I dont have a cat so so maybe thats what it was. It did smoke a little bit but not that much. So what do you think caused #1s death? Bent valve or worse?

The clacking is probably the piston hitting the valve...i guess its time for a 350.

 

Was the engine running okay BEFORE you adjusted the valves? Why did you adjust the valve? Were they making noise?


IF the engine was running fine BEFORE you messed with the valves, and since you're getting ZERO compression on one cylinder, I'd definitely check that cylinders intake and exhaust rocker arms. Make sure they move when the engine is rotated.

The lifter on that cylinder could have failed, causing it to bleed down, and when you adjusted the valves, you could have adjusted it too tight, thus keeping the valves open the whole time. That would be your cause for 0 compression in that cylinder.

If it were me, I'd go to the cylinder that read 0 psi. Take BOTH rockers arms completely off that cylinder. Now recheck the compression on that cylinder. If you now have compression you've narrowed you're problem down.

Check for a broken or bent pushrod etc. Then install the rocker arms. Adjust them with the engine running... loosen them until they are "clacking" loudly. Now tighten them until the noise stops. Then back them off until they JUST START to make the clacking noise again, then tighten then a 1/4 to a 1/2 turn.


HTH
Chris
85 IROC

 

I had a problem exactly like this almost a year ago. I was driving the car normally then all of a sudden, it started clicking loudly and running extremely rough. When I got the car home I started checking all the easy things and didn't find anything. I suspected it was valvetrain related. When I took all the plugs out, I found my problem. The # 6 plug was completely deformed as if a foreign object had gotten into the cylinder. Does your #1 plug look like anything may have hit it? Upon further inspection, after I took the valve covers off, I noticed the spring on the #6 intake valve was compressed a bit more than all the others and the rocker was loose while at TDC. It turned out the the foreign object, had bent the valvestem. After taking the head off, the piston surface was marred and there wasn't anything in the cylinder. I never did find whatever it was that got in there.

Do both valve springs on the #1 cylinder raise back up to their original height? Even the slightest difference will leave the valve open enough to give you no compression. Did you check the rockers on the #1 cylinder at TDC or did you just start adjusting them as the motor was running? Also, like was said earlier, check your oil to see if there are any obvious signs. Is there coolant in the oil (milky looking oil) or oil in the coolant (usually you can see small deposits of oil floating around at the radiator cap)? Either way, you're most likely going to have to pull the head in order to see the full extent of the damage.

 

Ok. I redid my valve seals a few weeks ago and readjusted the valves. I felt I didnt do a great job so I redid them. I loosened them till they clicked then tightened then 1/2 turn after they stopped clicking. Car did run smooth but didnt feel like right all. It hasnt for awhile. Feels like it had a miss at idle and ****. After readjusting the valves the car ran great for about an hour before this happened.

The valves on #1 appear to be working like they always have. The springs are new so i dont think a spring is broken. It sounds like something is inside the cylinder tho..like maybe the valve bent and the piston is hitting it or something.

I was gonna pull the heads today but it looks like its gonna rain so I will have to wait.

the plug does not look like anything hit it but every plugs is completely black.

as of right now im more worried about the noise than the dead cyclinder...the noise sounds like its coming from the crank

Let me add that my oil pressure sucks...after the car has been ran awhile it will go down to 10psi at idle and will rarely go above 30psi at any other RPM.

 

ttt