2005 LR3 Cooling Issues

Discussion in 'LR3' started by LR3inSB, Oct 13, 2018.

  1. LR3inSB

    LR3inSB New Member

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    Jun 5, 2011
    Truck runs fine and warms up normally, then once it's warm it gets really hot fast.
    Blew the upper radiator hose off on the highway.

    Tested Oil - no coolant. Tested coolant, no gasses. So maybe the head gaskets are fine.

    Replaced the water pump and the thermostat. No change in behavior.

    Pulled the radiator to have it flushed and the nipple for the coolant tank hose fell off!
    Replaced radiator.

    Replaced both radiator hoses and when replacing the one connected to the cabin heater, it's nipple just disintegrated!

    So, trying to figure out how to force flush the system BACKWARDS before I connect the new radiator in case it's got bits of crap in it from disintegrating plastic parts.

    So, I was looking at the thermostat housing (replaced 5 years ago because it cracked) and trying to figure out how it actually works.

    Anyone have a diagram? I've searched and have not found what I'm looking for - specially the housing and how it works.

    Any suggestions on flushing the system?

    Any suggestions on what the problem might be?

    Thank you!
  2. DiscoNels

    DiscoNels New Member

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    Mar 16, 2011
    My experience: I've blown off the top radiator hose twice myself, both at very inopportune times while off-roading. After the first time it blew off I put two hose clamps on but it still blew off the second time. V8 4.4L (I'm assuming you have the same)

    The only way it can be over heating is because there is an air pocket in the engine block. I had to remove the top hose and pour coolant down the hose directly to the engine block. Filled it till it was full up, and reconnected.

    Under the plastic engine cover (remove the cover) you'll find a plastic T-valve with a brass cap. You need to unscrew the cap a bit and let air escape from the top of the engine while it warms up. Lay down a towel or rags to soak up the spewing coolant. Let it go until air stops bubbling out and a steady stream of coolant is coming out.

    That should get the big air pocket out and then the coolant reservoir tank should be able to get rid of the rest in the system. Be sure to turn your heater on full heat to ensure you include that part of the system when removing air bubbles from the top bleeder. You may have to attempt this a couple of times.

    If you haven't replaced your plastic T-valve with a solid metal one yet, you should do this now as you may find when fiddling with the plastic one, it will disintegrate. Better to do in the driveway than on the roadway. Here's the one I bought from Cross-Axled Customs and it works like a champ and I'll never have to worry about the thing blowing again. Works on RR Sports too!
    PWD2 likes this.
  3. remember5

    remember5 Full Access Member

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    Nov 26, 2014
    Attached is a description of the 4.0 system - my 4.4 .pdf is not correct for some reason. Hope this helps. Also I can tell you I had the same issue and had to re-bleed the system a couple of times to keep it from overheating but eventually it stayed at normal operating temperature.

    Attached Files:

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