Bought my 00 disco about 6 months ago. The SES came on with P306 and P300 a few times also sometimes it does not start. It cranks but no start. Usually I just turn the key in the off position and then try to restart again and it fires up. So I replaced the plugs and wires thinking they needed to be replaced anyways at 100k miles. The check engine light came back on with the same codes but not I also have a P308 code too. I did buy the cheap autozone wires so maybe thats the cause....

Off to the bigger picture. overheating and horrible LR cooling system. Was on my way back from vegas and busted a upper rad hose. So finally got her back up and running now from time to time she overheats. So I recently replaced the thermostat and also attempted to bleed the air out as you guys suggested on this forum. Every time it gets hot and I let it sit overnight to check to coolant level the res is always empty. I keep adding coolant and water but dont know where its going. I checked the oil no gray and no smoke or water coming out the pipe. Any other ideas or suggestions? Taking it somewhere so they can **** it up more than it already is is not an option.

ohh yeah forgot to mention I still hear the water flowing noise coming from the heater core or whatever you guys want to call it, so I know theres still air in there...

 

You have a blown head gasket.

 

Ditto....and them some....

 

****....would the 306 and P308 be from the the blown head gasket? I guess a compression test is in order to verify what you guys are saying. Then again it seems whenever there is a cooling problem most of these forums automatically say yup blown head gasket....

 

dude the coolant is going out the tailpipe...

 

The coolant res is ONLY empty or low when it overheats which is whenever it feels like it....

I can drive it for 2 hours without the gauge moving then the next day I drive it for 10 min and it overheats. I am in denial about the blown head gasket, no smoke/water out the pipe and the oil is nice golden color and same level since I did the oil change. Ive blown head gaskets before so I know what happens...

 

Is this a challenge of the mighty Spike?

Interested to hear where you guys think his coolant might be going if he's not getting tailpipe steam or oil contamination.

 

The only thing I think is intriguing is why it only happens sporadically? The fact that the problem is intermittent would also explain why you aren't seeing anything in the exhaust when you check.

The P0306 and P0308 codes are for misfires on cylinders 6 and 8. P0300 is "Random/multiple cylinder excess emissions detected"...no doubt from burning coolant...

There's only so many places it can go. If it isn't leaking, or ending up in the oil, then by process of elimination it must be expelled via the tailpipe in one form or another.

 

Id still like to believe that when I replaced the thermostat I didnt get all the air out the cooling system. Since Ive replaced it blurped the air out, I have probably added 2 gallons of water. Also I know the SES codes mean just not sure if they are related to the cooling issue. When the SES light comes on I can feel the misfire, but when I restart the vehicle the misfire is gone....thats why Im leaning towards spark plug wires and/or coils.

 

so by your estimation how many gallons have gone in?......your in denial but okay...