My 87 z28 305 had been acting up come to find it had a misfire. I found the cylinder took out the spark plug and it had oily deposits so I changed it and made sure the wires had current and they did the cylinder still misfired seems like its dead im running on 7 cylinders I figured it be the piston rings or valve seals bit my oil consumption is normal and all other cylinders are working fine there is a little puff of smoke when starting the car but that's due ti a coolant leak and if it was the rings or valve seals my oil level would be much lower. Im at a dead end help please? ???

 

Burnt valve

 

How can you troubleshoot for that?

 

Idk when that happened to me I just opened it up and looked

 

Around how much is it on repair costs? ??

 

That would depend on a few things, but mostly if your going to be doing most of the work yourself.

 

yeah if you do it yourself its around 150

 

I had heard if a test to hold a towel on the tailpipes and if it was being vacuumed in it was the burnt valve I attempted it this morning after starting it up but it blew out the exhaust as it should????

 

Give the engine a compression test and a leak down test. Google it if you don't know how.

 

What he said^^^