QuestionQUESTION: You have been immensely helpful in past with issues, so I am hoping you can assist with a very frustrating problem my mechanic and I are having with my 2001 Disco II.
My Service Engine Light has been intermittently going on and off. The codes read, that it has misfires on cylinder #'s 3, 5, and 7. We changed the plugs and wires, (we noticed #7 wire was arc'ing) and for 2 mos that seemed to have solved the problem. Then the Service light flashed back on, showing again that cylinder #'s 3, 5, and 7 were misfiring. Both coils were then changed. Within 5 miles of driving the vehicle the Service light flashed on again.
I am fairly certain it is the same issue. The vehicle will be running fine then hesitate slightly, run a bit rough, light comes on, then it is fine....this is what it did prior to changing the plugs and wires. I trust the shop. They work on Land Rovers and Mercedes...it is a European Car Maint Shop. My father, a retired mechanic seems to think it is a vacuum leak that is causing the vehicle to lean out. Finally, when this happened used to be only on hills, now it is on level pavement as well. The vehicle is well cared for, has a lot of miles 181,000, but as I said, almost everything has been replaced, as you can imagine, haha.
Thank you for any help you may be able to give us.
ANSWER: I am sorry to say this sounds like an engine going bad. The blocks develop cracks, and coolant gets into the cylinders. This accounts for the rough running and misfires. The problem often starts under heavy load (hills) and progresses to flat ground. Does the truck use coolant? That would pretty much cinch it. DO a Google search on Land Rover liner failure and I've got some articles that explain with photos.
Sorry to have likely bad news
John
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QUESTION: Hi John,
Thank you for your quick response. I hope you are incorrect, but not holding my breath....The garage also performed a compression test on all 8 cylinders and a cylinder leak test and all read strong with no red flags. The vehicle does not use coolant either. The hesitation and rough running maybe lasts for 15-20 seconds and then all is back to normal...
Anyway, if you are correct and these tests were not, and I keep driving the vehicle, what may happen? Will it overheat and that is it? Will it just stop running? In other words, when it fails, how will it?
Thank you again sir.
AnswerIf the engine is going bad the coolant loss will worsen, and you will get misfire codes on the middle cylinders (3,5,4,6) as opposed to the ends (1,2,7,8) You may see more steam in the morning and it will start overheating. Eventually it will fail through overheat
