Two days ago a friend was driving my 99ZM6. I was in another car and I told my buddy in my car to get on it. He went first second then first on accident at about 75 MPH. After that car had SES light flashing and I scanned it it said Cyc #3 misfire. The car has 55,000 miles and original plugs and wires. So I replaced them with NGK's and thundervolt wires. I thought it would fix it but I hear ticking from exhuast and car runs like **** from 1500-2800 RPM. After 2800 car runs fine. I think he bent a pushrod. What do you guys think???

Thanx, Luke

 

He either bent a pushrod, collapsed a lifter, or broke a valvespring. Consistent misfires on a cylinder is usually indicative of a broken valvespring. If you bent a pushrod, the ticking would remain.

75mph in first gear is over 7500rpm. You could have done a lot of damage.

 

probably a bent pushrod, at least that's the best you can hope for... time to pull the valve covers and find out.

Oh and make sure you get an aftermarket shifter... they go a long way to preventing mishaps like that. Also don't let that friend drive the car again!

 

Is it a constant ticking, or just every so often?

 

I did the same thing at the track. 1-2-3-2... My car has a constant tick now that hasn't gone away. Stupid me. Went to the track again, but the car ran the best times I'd seen.

So apparently I have a bent pushrod and not a collapsed lifter.

So constant ticking is more than likely a bent pushrod, but you may have something else because my bent rod doesn't seem to have caused the performance loss or rough driving that you're seeing.

Crack that baby open.

 

sounds like a bent pushrod, like Tranzor said its the best u can hope for. might as well get a cam now since ur gonna be messing with the valvetrain.

good luck

 

Before I realized the problem I raced a corbra that is about dead even with my car. After the problem occured it was still even. When at WOT car run pretty good.

 

UPDATE:

Pulled the valve cover, springs, rocker arms, and pushrods are fine. What else do you guys think?? But on the bright side I found out the car has 7.4 MTI hardened pushrods. That was a suprise.

 

Well, I'd do a compression test first. If everything checks out, pull the heads and continue inspection.