1999 Discovery II
180K

About 20K ago I replaced my coil (OEM), Wires (STI), and Sparks (OEM). I have just driven to Houston TX from Charlotte NC. Once I got here the truck started a misfire on cylinder 2, I checked the plugs and wires and they look good. Later that day the misfire moved to cylinder 2,3, and 5. Since these are all on the passenger side coil pack. I ordered a new set (Both Packs) and replaced. When I fired her back up i had a HARD knock in the top of the motor and got codes for a misfire on cylinders 2,3,4,8. I double checked that all the spark plug wires are corectly installed and in the correct place on the coil.

At this point I am lost. I was supose to be in NC today and have a moving van waiting on me to get the truck running at a extra cost of $75 per day.

Any help would be great.

Thanks,
Dean

 

Stop driving it or even starting it.
What brand of plug, what gap?
If you can't figure it out, PM me your number and I'll call you.

 

They are a champion plug but I did not gap them, they where instaled by a shop about nine months ago. At that time we replaced the heads, gaskets, coil pack, wires and plugs, and water pump.

I PMed my number to you.

Dean

 

So here is the update –I did a compression test and found that cylinder 2 was not holding any pressure. As I inspected it future I noticed what looked to be the valve holding open as I turned over the motor. I pulled the valve cover and found that the exhaust valve for cylinder two was held in a partial open state. I removed the rocker arm and push rods and everything looks to be in order. Even with these removed the valve did not return to the proper location. Additionally I noticed that the oil seal had worked its way to the top of that valve but all of the other appeared to be down at the base.

Questions – Is it likely that the valve seat has become free and that is keeping the valve from properly closing?

If not is it possible to bend a valve with a misfire?

Given that I just put these heads on a few months ago, I am not looking forward to getting all of the seals to get this fixed. Is there any way to fix this without pulling the head?

Also remember I am about 2000 miles from home trying to get this puppy back up and running.

 

Bump. Diagnosing a similar situation on my 1,3,5,7 misfire. What did you do to solve the misfire?

 

This thread is from 2011 and the user who started it hasn't been active since 2012. Bumping an old thread is pretty much useless.