Land Rover Repair: land rover- discovery cylinder mis fire, land rover discovery, 2004 land rover discovery

Question
I have 2004 land rover discovery. check engine lite started coming on. Advance auto diagnostic test said cylinder 6 mis fire. What should  I do?

Answer
Hi Gary,

could be spark or compression related.  You could try replacing spark plug, the least expensive means of testing.  It's rare but sometimes this can happen.  When you remove the spark plug, you'll see if the plug is fouled up in some way. There are charts on the internet that show you how a plug should look like under normal conditions.  If the plug is wet or covered in black soot, you could have a ring problem within the cylinder.  

Then there is the possibility that you have a headgasket leak and the compression is not right.  A compression test at a local garage can verify this and IF it's the headgasket you are looking at $2000 or more (depending on where you have it serviced).

There are other possible causes but the above is more common.

Best of luck,
JohnMc