Hi all... thanks for the add...
Have a 2004 V8 disco 2 w/145k miles that I just bought used. Vehicle starts up and runs but is evident that it had a misfire or something going on. Pulled the codes and had multiple misfire codes on cylinder 2,4,6,7. Replaced spark plug wires and plugs with minor improvement. Up until this point the truck still starts, idles and drives but lacks power, although no over heating or coolant smell in the exhaust. Oil isn't milky. Did a compression test, plugs out, wot, pump/ spark disabled. Ended up having the 2 middle cylinders on driver side with 0 and 8psi compression. Poured oil down each cylinder and did another test with no change in pressure. Used bore scope to visually inspect all cylinders. Both bad cylinders have heavy carbon and oil deposits with no visible damage to piston heads or cylinder walls that I could see. All other cylinders had 180-190 psi. Most looked normal with some carbon build up or fairly clean.
At this point I'm leaning towards a valve or ring issue unless there's something else that could cause oil to enter the combustion chamber. When I get back home I will be pulling the heads to take a closer look. I'll also be testing the coolant for co2 to check for a cracked block.
Does anyone else have some further insight, experience or suggestions in this issue? Sorry if there's any info that I missed.
Have a 2004 V8 disco 2 w/145k miles that I just bought used. Vehicle starts up and runs but is evident that it had a misfire or something going on. Pulled the codes and had multiple misfire codes on cylinder 2,4,6,7. Replaced spark plug wires and plugs with minor improvement. Up until this point the truck still starts, idles and drives but lacks power, although no over heating or coolant smell in the exhaust. Oil isn't milky. Did a compression test, plugs out, wot, pump/ spark disabled. Ended up having the 2 middle cylinders on driver side with 0 and 8psi compression. Poured oil down each cylinder and did another test with no change in pressure. Used bore scope to visually inspect all cylinders. Both bad cylinders have heavy carbon and oil deposits with no visible damage to piston heads or cylinder walls that I could see. All other cylinders had 180-190 psi. Most looked normal with some carbon build up or fairly clean.
At this point I'm leaning towards a valve or ring issue unless there's something else that could cause oil to enter the combustion chamber. When I get back home I will be pulling the heads to take a closer look. I'll also be testing the coolant for co2 to check for a cracked block.
Does anyone else have some further insight, experience or suggestions in this issue? Sorry if there's any info that I missed.