Diesel p38 overheats when towing

my diesel auto p38 drives ok bt when towing my twin axle caravan it over heats. it dose not bubble or steam that much but it seems just overflow out the expantion tank . now i know my radiator leaks a little where the cores meet the plastic tank bit at the bottom could this be my overheating problem or is it more likley to be the head gone iam going to put a new therostat in but i wanted to know whether it could be my radiator before going and spending over a hundred pound on a new one anyone know what my problem could be please help

put a new rad on not second hand, if it leaks throw it in the bin, cutting corners now will cost you ££££££££££££££££s later

If the rad leaks it's loseing pressure which means it will boil at a lower temperature. Change the RAd and while you are at it check the water pump, the plastic impeller ones break up.

Start the engine and get it up to operating temperature. Open the bonnet and try to stop the engine cooling fan with a rolled up newspaper. If you can stop the fan the viscous coupling is fooked, replace the complete fan assembly with an oem unit.

And fit a new radiator, thermostat and water pump while your at it, no point in doing half a job, it'll only cost you more in the long run...

If you know your rad is leaking,change it asap,and everything else as listed,could save you loads of money in the long run.I would check your caravan brakes in case they are binding while your at it

From a man who's been there I'll totally agree with the two above. Changing the whole lot is still cheaper than a knackered head and if you don't do the lot you'll worry every time you hitch your tin snail on the back.

Can i state the obvious?
If its boiling up through the expantion tank the caps not holding pressure!
New cap island 4x4 about £10
But the leaking rad will still let pressure out. so youll still get an overheat cos like said above water will boil if its not pressurised

Going with what the others have said change radiator , water pump and thermostat and sleep well at night either at home or in caravan ..

ok thanks everyone for the pointers and advice i am going to do as suggested and change the radiator,waterpump,thermostat and i will also replace the cap on the expantion tank to be on the safe side

micky22 said:

ok thanks everyone for the pointers and advice i am going to do as suggested and change the radiator,waterpump,thermostat and i will also replace the cap on the expantion tank to be on the safe side

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hooray,here is someone who asked for advice and is taking it,well done.it's about bloody time as well.

micky22 said:

ok thanks everyone for the pointers and advice i am going to do as suggested and change the radiator,waterpump,thermostat and i will also replace the cap on the expantion tank to be on the safe side

Click to expand...

Check the thermostat works in a pan of boiling water before you fit it, there have been a lot of duff ones recently

Go for a genuine Land Rover/BMW thermostat not after market. Check the baffle in the new radiator. I bought all new stuff when I had the same problem including a cheap thermostat, went back to the original (OEM) one which was better but not perfect so put a genuine one in - much better.

micky22 said:

ok thanks everyone for the pointers and advice i am going to do as suggested and change the radiator,waterpump,thermostat and i will also replace the cap on the expantion tank to be on the safe side

Click to expand...

Don't forget the cooling fan assembly as well...

micky22 said:

ok thanks everyone for the pointers and advice i am going to do as suggested and change the radiator,waterpump,thermostat and i will also replace the cap on the expantion tank to be on the safe side

Click to expand...

did you check your caravan brakes ?