Thread: Water temp near the red

Is it bled correctly?

It sounds like an airlock. Making sure that the system is fully charged with coolant can be tricky as I found out when same thing happened on my 300Tdi Disco.

Thanks for the replies...

The book says 11.5 litres and after poruing this in, the coolant rested half way up the expansion tank as per the book...

When I filled the coolant via the expansion tank, i had removed the two brass plugs - one from the top of the radiator and the other from the top of the thermostat housing and waited until new coolant flowed out of them before I screwed the brass plugs back in...

Unless there is an air lock in the block?

Is there a secret to bleeding?

Cheers
Andrew

Hi Andrew, I had exactly this problem on my 300 Tdi Disco 1. Having flushed the system with my garden hose, replaced thermostat and all the hoses bar the heater hoses (this was in preparation for a trip up north to Exmouth and Karijini recently) I refilled everything with coolant and set off. All was well until we hit the freeway when exactly as you described, temp gauge reached for the sky. Well long story short, my heater matrix was blocked with crud from years gone by so, as the coolant refilled there was an airlock across the top of the block causing the problem. I disconnected the heater hoses, blasted them out with a pressure washer (kindly supplied by the radiator specialist in Carnarvon; thanks guys, you saved my holiday), refilled the system and bingo, all was well. Maybe this is your problem too. Does your heater blow hot air? If not, almost certainly that's the cause, mine now blows air just bearable heat wise on full fan, before it was just warm. Remember to open the heater fully onto hot when you blow it out with the water. Finally I refilled the system very slowly via the thermostat housing using the small radiator overflow pipe to bleed the top of the rad. This led to the coolant tank being overfilled but, when all was full and sealed I just syphoned the excess coolant out of the tank with a squeezy bottle and tube.

My main problem was the addition of a roof tent for the trip acting like a parachute which is why the temp gauge was fine 'til we got out of town and hit the 110km speed limit, the extra drag then caused the motor to overheat. Hope this is of some use.

Dags

Thanks Dags

I have been running around for the past fews with the heater lever on heat, but have not felt any hot air coming into the cabin.

Today I disconnected the heater hoses and flushed the heater core with fresh water. There didn't seem to be any blockages, as water flowed freely in and out of the unit.

I might try tonight and disconnect one heater hose and blow through it making sure the water flows properly.

Cheers
Andrew

Before you go any further do the job properly.Remove the rad and get it rodded,It is long past due and refit and take it back to a rad shop,just fill it with water and drive it straight there and just them to flush it and refill with coolant.Your rad will need to be rodded or by now it could have started to rot and need a re-core,don't do the cooling half-ar%ed,it's right or wrong,no inbetween. Pat

Radiator was removed and cleaned recently, but was installed with original coolant - just topped with demin water, thus reducing the glycol capacity dramatically, which is why I have been busting to find time to change the coolant.

In the 3 months I have had the vehicle the temp gauge has never moved from just above the C. I have taken it for a very quick 1900 Kms round trip recently (Brisbane-Emerald-Brisbane) with no over heating issues.

I will try and bleed the system tonight before I leave work by removing the heater hose at the back of the block and seeing what comes out.

Cheers
Andrew

when bleeding the cooling system have the engine running and the heater on and then let it run up to operating temp( thermostat opened).