Intermittent overheating on a 200tdi

Hi ive recently bought a 200tdi 90 (genuine def not disco) it keeps overheating. Temp gauge goes to red very very quickly but if I change gradient I.e down hill it seems to go back down. I haven't driven t far due to worrying about overheating. Both top and bottom hoses from the rad are warm/hot so waters circulating and the heaters working on hot so I presume thermostat is ok? The header tank is cold at all times. It has had a new rad fitted. Any ideas? I'm going to flush coolant tomorrow. I've read about dodgy Earth on the temp gauge, how would I know? Any ideas appreciated thanks

As per a concurrent thread try cleaning/adding new earth straps (cheap as chips from any auto shop, just fix them between engine/chassis/gearbox etc ). Might also be a dodgy temperature sender. Might also be genuine overheating (failed water pump, HGF etc).
Is your coolant at the correct level and with the 'right' antifreeze/coolant concentration?

bluedog333 said:

As per a concurrent thread try cleaning/adding new earth straps (cheap as chips from any auto shop, just fix them between engine/chassis/gearbox etc ). Might also be a dodgy temperature sender. Might also be genuine overheating (failed water pump, HGF etc).
Is your coolant at the correct level and with the 'right' antifreeze/coolant concentration?

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Hi ive read into the earth problems and am a little daunted as to where to start is it just a case of making up some fresh cables to link engine to chassis and then body? Any idea how I'd test water pump? How would I know if head gasket had gone?the header cap is fine displaying no cloudy fluid just clean oil. Water and coolant all fresh.

If you've got the correct coolant/water mix and the level doesn't fall and you've got no oil in coolant and no 'Mayo' in your oil then I'd guess earth or dodgy sender. Earth cables are cheaper to buy, get one and bolt it between a bolt on the chassis and a bolt on the engine, it really is that simple, you don't need any electrical know how to fit them!

Thanks fella ive been reading about it since your advice and it does look promisingly likely. Fingers crossed its that simple a fix

Be sure to update your findings!

If it helps, I put an earth strap from engine mounting bracket (on the near side) and fastened it to the engine near the alternator,i was having similar problems, the more I had to put my foot down to get up a slight hill the higher the gauge went,been out for a run today and so far so good,start with the cheapest!

As soon as its gets hot pull over engine off and feel the rad, I reckon you may have a fooked not opening stat, make sure you get a proper 200 one with the bypass cut off on the back of it, do not run with no stat, not a cheap crappy one either.
200tdi defender quite possibly one of the easiest to repair cars ever made, which is just as well because you will be doing plenty of work on it!

Thanks glfor all this help guys. I think I'm going to replace thermostate just to be sure. I haven't had time to look at earth sleeving today but I'm thinking its electrical as when I pooped out earlier in it the gauge went right up but when on the throttle seemed to come back down. Also the battery light comes on intermittently when I first start the engine

Jayjaytb said:

Thanks glfor all this help guys. I think I'm going to replace thermostate just to be sure. I haven't had time to look at earth sleeving today but I'm thinking its electrical as when I pooped out earlier in it the gauge went right up but when on the throttle seemed to come back down. Also the battery light comes on intermittently when I first start the engine

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you are not meant to poop in it.

check the wire going to a bolt on the engine side bulkhead to the right of the brake servo is nice and clean and tight. it's the dash earth

go out, when hot pull over.

jump lead, one to bat neg other engine block, see if the gauge drops.

if not, go place your hand all over the rad, look for cold spots. (even though, it is new)

presume you bled it properly?

also, a tenner buys you an ir temp gun. very useful for checking bits n bobs.

Although its a new rad is it full of mud from off roading? I have a 200 in a Discovery. I used it to trailer a new purchase home and although fine on the outward journey when I came back loaded it was overheating. Turned out all I needed to do was wash out the rad, fins were blocked with mud.
Kev

Hi guys now mud as I only use the truck to potter round my sheep. I've checked and there's no obstructions etc. I used the truck briefly today and it seemed fine but every so often the tempreture would go to maximum for a while then back to normal. It almost seems as though it changes depending on road gradient if that makes sense. I may be totally wrong and it may just be coincidence. I'm hoping it's a intermittent epectical problem. I'm hoping to find time to give it a good look this week sometime. I'm going to change stat and flush coolant just to be safe and am also tempted to change water pump? What are people's thoughts?

Personally I would just check/add earth's first,and go from there.

Jayjaytb said:

a intermittent epectical problem.

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Yep, definitely one of those!

:hysterically_laughi