I have a 2001 discovery SE. About 2 years ago we had the heads shaved and all the gaskets replaced. 2 months ago the top hose blew. I had it replaced. 2 days ago it began to overheat and it blew out all the coolant. I had it filled and checked for leaks. there were no leaks. Then I replaced the T-stat. It was fine for 2 days. While sitting in idle I noticed the heat did not work. Now it's overheating again. Any advice? It has about 90,000 miles. The mechanic said that the water pump is fine.

 

Have you been running DexCool? Could be your reservoir cap. If not the pump or thermo, it would be the next place I go (about $20 too, not bad if it's the problem). Stop driving it until you get it sorted. Good luck.

 

Stop starting the engine before you toast your engine. Send me your number and I'll walk you thru what needs to be done.

 

For future reference, what's the procedure?

 

I suggested he send me his number, not to talk about how to bleed the system, he is past the spot already, but what to do before he drops a sleeve.
As for bleeding the system, do it only when stone cold, with the engine off, remove the bleeder screw and start poring fluid into the bottle, continue poring till you have a steady stream of coolant coming from the bleed hole, replace the screw and cap and go drive it for 5 or 10 minutes with the heaters both on hot and hi fan speed.
Let it sit till cold and refill the bottle up to the cap line and recheck it a few mornings later.
Only check the fluid level or bleed the system when stone cold.

 

Mike, where is the bleeder screw? On top by the hose connections? I might be thinking about something different.