new radiator March 2016
new water pump Feb 2016
new hoses April 2016
new thermostat 2 weeks ago, then put old one back in. Old one was working fine.

No waterfall. Bleeding cooling system following LR manual. Heater on, expansion raised, bleeder screw open until just coolant flows, uphill parked.

Pressure tested no leakage at 20psi for 3-4 hours. No drip leaks underneath.

Just overheats after about 15 mins running. Driving me insane.

 

I mentioned a new radiator because you will never get little debris out of it. I'd be more worried about debris getting stuck in the heater core lines/heater core, but they could still get stuck in the radiator or engine cooling ports as well.

Was the replacement thermostat an aftermarket proline/motorad unit?? If so those aren't to reliable and I've seen plenty labled and sold as 180F units when actually they're 190F's.

If you were to get all the air out, but somehow you have a leak or are getting air in the system the heater core is going to gurgle like crazy on cold startup under acceleration.

 

The little plastic bits may have toasted your water pump. Did it always overheat through the whole list of repairs, or did that start somewhere along the way? I'm guessing it started somewhere in the process because you wrote "old thermostat worked fine."

 

I don't think a metal impeller spinning at 2.5k is gonna get defeated by a brittle piece of plastic. I'd think it would just blow it into smaller pieces and send it on it's way to the heater core, radiator, or to a closed thermostat.

Also I noticed there wasn't a fan clutch on that list. That could be some of the issue if it's not helping to pull in more air at idle. 03/04 = buy a 99-02 fan blade, and replacemebt fan clutch.

 

How did you bleed with the engine stone cold and the heater on at the same time?

I'm guessing you were posting in a hurry and you didn't really bleed it while it was running?

 

Fan clutch test - use your hand to spin the fan with the engine cold. If it spins past one rotation, it's toast.

I agree, little plastic chunks won't stop the water pump from turning. At worst, they'd block water passages, but I doubt that would cause this problem unless they were huge chunks.

 

Fan clutch is tight. Cannot spin past 1-2 oclock from 12 oclock.

Was bled with engine running from stone cold as per LR manual, Shane, Number9, on earlier pages of thread. By the way, opened bleeder screw with engine running, rev'd engine and coolant gushed out stronger. Think water pump is working.

Heater was on.

I pieced together found bits of plastic and matched against missing lip of blown tee- connector. Whatever is lodged in the cooling system is smaller than a pencil point. There may be no plastic at all because unaccounted bits of plastic probably fell out of the hose when the thing blew apart.

Anyway, my next step is to reverse flush then temp gradient check the rad, water pump, hoses section by section, once infrared temp gauge and OBD2 Torque coolant temp monitor get delivered.

If still overheating then start tearing things down, replacing parts some that are just 2-3 months old starting with the thermostat, then rad, then water pump, then heater core. Can't believe this.

 

If the thermostat is not the OEM 180F unit it needs to be replaced regardless!!! Aftermarket ones are crap! Spend the 80.00 and get an actual functional thermostat.

Throwing parts at it is kinda silly. First replace thermostat with OEM 180F grey thermostat, second get an OBDII Scanguage II, Ultragauge, to monitor temps, add 50/50 coolant with the nose up, startup let idle and monitor temps.

I doubt the waterpump is the problem unless your impeller is stripped, or plastic and broken which is causing it not to move any coolant. Make sure no debris is in front of the radiator as well.

 

wow, this may be the most persistent overheating problem I've seen on the boards. keep at it, you'll get resolution.

one other thing came to mind. I once had a heater return hose go bad and it would balloon up when it got hot allowing air in at the connection. replaced hose, tightened worm screws all around, done deal. maybe check all hoses and tighten connections if you haven't already.

 

He said it again:Manual does call for bleed with engine not running. OP doing his way.
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