I changed plugs to Bosch +4, new wires some other brand from Napa not magnecore, and new coils.

Still have misfire on #8 checked compression on #8 at 75Psi compared to #2 at 80psi and Spark is good. Spark plugs look oily though???

Could it be a sensor that is not reporting as error?

 

IMHO the compression test is very low, maybe less than half what would be expected for multiple strokes of the engine. The old school method was to add a spoonful of motor oil in thru the spark plug hole, repeat the test, if readings came up, it indicates rings, if stayed low, valves and/or head gaskets.

Rings can obviously leak oil, and so can a head gasket.

Might want to repeat test on all cylinders, compare bank to bank, and all those on one bank. Rule of thumb is within 10% variation. A new engine can produce 180 PSI or a little more.

 

x2 you need to redo that test those number are way to low but do all the cylinders. You do not say what year or how many miles are on it, it could also be valve guide seals. Get all your number written down then try a table spoon of oil in each cylinder and see if you have a large increase in psi.

 

Seems like if it was guides/seals/rings and those compression numbers he would also notice high oil consumption and blue cloud following him... and he would not have enough giddyap to outrun the cloud.

 

Sp why put in a new coil, Bosh plugs and cheap wires, don't see the logic there.
I agree, your numbers are way off, should be in the 150 range and consistant.

 

Compression test was on one turn on the engine. I tapped the ignition till it came around to the cylinder I was testing.

I had a code of P0308 misfire #8. Previous owner replaced half of the coil #1 to #4, all 8 cylinders had Champion plugs, and 8mm wires not sure of the brand? It's doesn't seem to be burning oil-oil level is good and clean...recently changed with mobile synthetic. No blue cloud out the exhaust or signs of radiator fluid.


2003 disco with 103,000 miles on it.

 

Then it sounds better, but you may still want to do a multi-spin test. Look over this post with listing by cylinder by turn... https://landroverforums.com/forum/di...89/#post217271

 

So, one turn of the engine is not a compression test, usually 4 to 6 revolutions are required to build full compression.

 

I also have the same problem with misfire and want to check compression. I just did head gasket job, replaced valve seals, have new plugs and wires, but somehow mechanic did not do compression test for the car and now it still gives the misfires. I was trying to find in RAVE what are normal compression rates and what is the best way to make this test, but I could not find any.

I want to do it myself and can you please write if you know how to measure compression with? and what is the normal range for compression rates in cylinders?

 

are the threads on #8 plug hole good? I had to tap 2 of the threads on mine that were missing.