P38 over heating 4.0 L V8

Hi all ive had over heating problems again its been fine over the last 5 weeks.
The first time it over heated i changed the theromstate and had the head tested all ok.
Second time 4 weeks later i changed the water pump
now its the third time, 5 weeks later so now what the viscus fan unit may be? i will test this tomorrow ill warm it up and try and stop the fan with somethink !

Possibilities are now the fan or a clogged up radiator. Is the radiator hot all over with no cool spots after running up to temp?

West Slope Rover said:

Possibilities are now the fan or a clogged up radiator. Is the radiator hot all over with no cool spots after running up to temp?

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Hi there yep the AA man had his temp laser all over the top
may be i should do rad as well at the same time.

If you've got the dosh to do it all, then cool. I'm curious what the fan test turns up.

West Slope Rover said:

If you've got the dosh to do it all, then cool. I'm curious what the fan test turns up.

Click to expand...

from what i have been reading if the engine is up to temp and you can stop the fan moving with the engine running then the viscous unit is faulty
ie not turning fast enuff.
so fingers crossed

Just ordered parts from p38spares.co.uk
£240 delivered

Delta351 said:

Just ordered parts from p38spares.co.uk
£240 delivered

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Hopefully all will be fine after fitting them. Good Luck!

Delta351 said:

from what i have been reading if the engine is up to temp and you can stop the fan moving with the engine running then the viscous unit is faulty
ie not turning fast enuff.
so fingers crossed

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did you manage to fix your overheating prob ? if so what was the reason?

Hi, i changed my viscus fan unit over and once again it over heated 6 weeks later!!!! ie yesterday, I saw the temp gauge going up so i switched the engine off waited for 10 mins for cool down and started it up and i drove off and gess what it went up to normal temp and stayed there
So now im changing the rad over.
Lets see how it go's!

rad changed over and over heated with in 3 milles!
i must have a blockage or the thermostate has gone again as it has over heated 4 time and might of cooked it!
Think ill buy an original thermostate this time!

Did you make sure to bleed all the air out of the system after the rad replacement? Try running it again and turn on the heater to highest temp and see if it blows hot or cold. Cold means you have air trapped in the lines. When I replace my radiator it took three attempts to get all the air out of the system.

hi there, how do you bleed the system?

Delta351 said:

hi there, how do you bleed the system?

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Here's a thread that covers it:http://www.landyzone.co.uk/lz/f10/re-filling-cooling-system-p38-176016-2.html

On my 4.2, I filled it at the high point of the system through heater intake line, then I just drove it cautiously up and down inclines and then rechecked the coolant level in the expansion tank. If you've burped some air, the level will have dropped and you add more coolant

Hi There

I'm unsure if your coolant flow set up is the same as on the disco 2 Thor, but i had a few issues with boiling coolant, and replaced the thermostat, but the problem re-occurred, i found a thread on a US forum that said there was a late change in thermostats for the v8, and that as a modification to fit the grey thermostat not the white, so i went to my dealer and he rebuffed that statement for 30 seconds then apologized and presented me with the updated one, its the same as fitted to the freelander apparently.

Don't know if this helps, but i would try and check your rad for temperature, mine stays red hot at the top and ice cold at the bottom, it seems as if the thermostat is barely open, but a year has passed and no re-occurrence, but i will say you have to be religious in checking your coolant level, as these v8's have a coolant loss issue and once you get air in then bingo boils every time.

Pat