Hello all

I am at a lose with what to do next on my 01' disco. The problem first arose when I got a misfire code for cylinder 5. Changed everything I could think of that would cause a misfire and the code seemed to go away. After a bit I noticed a tick that had gotten louder so I replaced everything from the camshaft up and hoped my problems were behind me. Less than 1000km later and I was on the side of the road with an overheating engine and combustion gases in the cooling system. Took it all apart again and sent my heads away to get them tested, re-surfaced, and new gaskets. Everything with the heads were fine. Rebuilt it again to find my overheating issue had not gone away. When I took the heads off I did notice it looked like the number 5 was steam cleaned.

Before wiping off residue

After
I am at a loss and don't know where to go next.

Could my overheating issue be caused by a cracked sleeve letting gases into the water jacket? Or is it more possible that I have cracked my block?

My entire cooling system has been changed and I will list everything I have changed and replaced below.

-NGK spark plugs
-HT leads
-Coils
-Coil relocation kit (Extinct)
-Inline thermostat (Extinct-180 thermostat)
-Cooling hoses
-Dual Electric Fans
-All gaskets from the heads up
-Head bolts
-Exhaust bolts
-Cam shaft
-Lifters
-Push rods
-Rocker assemblies
-Timing set
-Tensioner
-Serpentine belt
-Pulleys


Any incite will be greatly appreciated.

 

The main typical flaw is the radiator that clogs with sediments, its tubes are very narrow and prone to catch impurities in the coolant. Not on your list.

 

Based on the combustion gases in the coolant and the steam clean cylinder number five I think you have a cracked sleeve and block. They used to make block off plates to do a pressure test with the heads off, sometimes you can find them on ebay.