Thread: 3.6 TDV8 bad overheating on hills towing caravan

For $600 I’d stay original. Not worth changing in my mind.

Same opinion everywhere! None in AU so waiting to hear a firm time instead of the 1 week guess for LR to get one from the UK.

Fortunately my brother has 3 vehicles so 1 in sick bay for a week doesn't bring him to a stop, unlike me who only has 1. Yesterday I thought I'd have to walk 8 kms to the PO then back again when I had poked a hole through the old oil filter with a screw-driver to remove it from the cap then found that the replacement was shorter. Fortunately the spare was indeed the correct filter but that I had been confused when a NRV assembly in the filter housing cap had un-clipped and stayed in the old filter making the new filter appear shorter.

Originally Posted by theelms66

On your Original post you said top radiator temp was 113 and bottom was 103 . Sounds a little hot returning into the motor does it not . I dunno.

Only found out recently, 10C is the correct difference top to bottom in a radiator, so it would appear to be working correctly.

Before you change radiator, try running straight water without coolant. This site has some good info about cooling.

Motor Coolant Selection to help Overheating Engine

He was running 50% which I suggested was too high considering the overheating. I only ever use 30% but straight water would have been a worthwhile test.

A new radiator, water pump and top hose have been ordered. I doubt that he wants to now go to the effort of putting the old radiator back in to try straight water as he separated the radiator pack in-situ rather than drain the a/c system. I'll pass on the suggestion and link.

I own a 2008 TDV8 RRS and tow a 25 foot Jayco Sterling topping the scales just under 3 tonne. I've never had an overheating problem with it. It's done nearly 190,000 kms at this stage. 2016 we went from East Gippsland to Qld right up to Cooktown with all the attendant hills and mountains climbed without incident. Last year we went to Darwin and back down the highway turning left at Three Ways and crossing the Barkley Highway to Townsville and up to the Ingham area. We came home via Mount Morgan which is a particularly steep climb. We've just got home from a month up the Sapphire Coast from here. If my car was going to overheat it has had plenty of opportunity to do it towing our van. I tow at about 100km/h up hill and down dale, in fact when the car smells a hill it wants to accelerate up there. It's a beast for hills.
Now, I'm no mechanic so don't shoot me when I make this statement. The fan is behind the radiator and hence helps pull air through the radiator I assume. Is it possible that the fan itself could have been removed from the viscous coupling at some stage and been put back on back to front? I don't even know if that is possible but it's a thought. The radiator may be capable of handling normal conditions without the van and without the fan assistance but when towing the van and adding uphill to the equation, could be too much for the system.
Good luck with it.

Whilst my brother initially though that the engine had always overheated, he then recalled that it had not as he recalled the ease with which it pulled the van up hills at speed, regularly overtaking slower vehicles.

The fan is detached from the engine by unscrewing the hub assembly and the fan is never detached from the hub, so the fan blades cannot be fitted back to front. However I will pass on your comments and suggestion.

New genuine radiator, water pump and top hose were fitted Monday with the job expected to be finished yesterday but I haven't heard if the car is back on the road yet. The current hot weather will provide a good test.

The overheating problem has shown to have been resolved, with the old radiator being blamed. No sign of overheating climbing hills at freeway speeds in 40 deg heat. The RRS and van are already on a short trip before holiday time runs out.

My brother thanks everyone for your suggestions.