[rejectedstone]

I had a small crack in my theromstat housing. It wasn't really creating any major issues, but but I could smell a faint odor of coolant. When I closely inspected everything, I saw a very small crack in the plastic thermostat assembly. I replaced the entire assembly, and now my 2006 LR3 is overheating. The gauge climbs to the top. My scanner says the ECT is between 241-249. I read in another post that is too high.
Everything was fine until I changed that. I also replaced my Alternator, which shouldn't affect that at all.

I used a laser thermostat to read the block temp and it was around 209. I thought the new thermostat might have been bad, so I put the old one that I knew was working in there. It is still overheating. Could this be an issue with the system needing bled?

 

[RoverAsh]

Sounds like you have an air pocket in the system. Are both the upper and lower hoses hot?

 

[bbyer]

air pockets almost for certain

Bleeding the air out of the block is near impossible - it takes hours so that is most likely the problem.

Also it is not a problem you want to ignore - the block is not cast iron - it is no GM 350 for certain.

There are various posts about on bleeding but none of the procedures are quick.

You should have an air bleeder plastic tee in one of the little hoses under the black plastic engine cover on the steering wheel side of the engine - that seems to be the best way - just plan on peeing coolant a little bit at a time all over the engine for hours.

 

[mx468]

Bleeding procedure

You need to bleed it. Bleeding was real easy when I changed out my thermostat. I guess on the v8 4.4, you just run your truck to normal operating temp with all vents and heat cranked. I ran the truck for about 15 minutes got out while still running and than went and unscrewed the bleed screw slowly on the reservoir bottle, and waited until coolant came out, tightened and my truck warmed right up. I have a ultraguage which shows actual engine temps, I Highly recommend getting one of these!!!