L-series overheating

On my 2000 L-series, I noticed yesterday driving at 120km/h on freeway with aircon running,the coolant temp gauge started climbing above the normal halfway mark. If I slowed down a bit it would drop to normal halfway mark on the gauge. Outside temp was about 35 degrees C or higher. Looking at the radiator, I see some coolant leak around the bottom radiator pipe, and also on the top on the same side (pink residue from antifreeze). It was too hot to do a closer inspection. No loss of coolant is noticable in the coolant reservoir. Previously the bottom hose was a bit loose, and I tightened it up which stopped the coolant leak. However it seems to have started again, with some leaking where the radiator tank and core are joined at the top. Any ideas what could cause this? Could thermostat not operating properly have something to do with rise in temperaure above normal? Could loss of some water and pressure cause temperatoure to rise? Mileage is 132 000km. Any ideas will be welcomed.

That kind of outside temperature puts the minus 18 (and lower in some places) we had here last month distinctly to shame!

Anyway, what you describe sounds like your radiator is about to give out especially if its leaking between the core and tank. Bottom hose could be a bit soft too where its clamped up. Do the basic things first (pressure test, thermostat, flush out and maybe a new radiator) refilll and run again. How does the oil look? Brownish, brownish black or any hint of grey or water droplets? Ordinarily you're not too high a mileage or the speed but when you put the outside temp into the equation I would think it's having to work a bit more than usual. When did you last change the anti-freeze? If that goes off it can have a destabilising effect on running temp. As you may know it has two purposes; anti-freeze (as the name suggests, although.... and anti-boil to some extent in that it assists in the cooling too).

PS Its about 4 degrees here today, maybe lower.

Thanks for that. Tomorow they forecast close to 40 degrees C... then cooler weather again on Wednesday. The antifreeze was changed when I had the heater matrix done last year about Sept. Oil looks good (black and no sign of water). I think the radiator is about to go.... and can only get one from the main dealer at a whopping price. Will try some importers up-country... maybe my luck will be in. But first get a pressure test and see what it shows. Hippo parts are fairly scarce here... lots of Series, Defenders and Disco's though.

Temp will rise if the pressure is down - leaking radiator and hose - giving high guage readings. Looks like a new rad definitely on the cards. Do you get Radweld or C-lit over there? A sachet of that could seal a pin hole in a vein but not if its coming away at the tanks or if its too perforated or porous. An overdose of sealant can block waterways so best try and source a new radiator if the pressure test shows up like a sprinkler.

Radiator removed, cleaned and repaired. Gasket between core and tank was leaking. Other than that radiater is in excellent condition. Radiator shop replaced gasket and tested and all okay now. Did a test run today and all seems well. Lets hope it styas that way. Will be doing a nice trip this weekend which should confirm that all is well.

burn it with tyres full of doisel...

A lot cheaper than a new radiator then. Good to know they are fixable like that. (I just wish the ABS sensors would last - 3 in the past year!)