Not nessy-celery. If it is the incorrect sender fitted, the temp will rise into the red when under load. The themostat then opens causing the temp to drop again. Seeing as 300tdi's are overcooled, if the sender is mis-reading the temp range then it could be it's showing too low when engine load is removed when the vehicle is on the downhill stretches in the current cold spell we're having.

Fair enough Rats - gladly bow to your knowledge. Had only previously come across the wrong sender reading hot and staying hot rather than fluctuating widely.
 
Fair enough Rats - gladly bow to your knowledge. Had only previously come across the wrong sender reading hot and staying hot rather than fluctuating widely.

I could be wrong yet. I was just putting forward another possibility.:)
 
sorry ratty;
can you let me know what last post means?
will my car die?
car done 50mile round trip at weekend never missed a beat, but gauge up and down all the way.
i will try and change gauge and sender, though not got a clue how to get old gauge out?
 
Undo the the screws round instrument panel that will then pull forward enough that you can undo the connections and undo the nut that holds the clamp that holds the gauge in place, then it just comes out.
 
Update:
When I took my landy to have the fuel guage fixed, he took it upon him self to fit a 200-300 guage??
Very nice of him yes, BUT

It seems to work very well but reads slightly hotter than it should in my opinion?
Sits at 3/4 on a journey and just into the red when off-road

My cooling system is in tip top condition so no problem there!

When I fitted the black band sensor it said it was cold constantly.
With old 19J guage said it was red hot all the time so would of been perfect in my opinion.
 
sorry ratty;
can you let me know what last post means?
will my car die?
car done 50mile round trip at weekend never missed a beat, but gauge up and down all the way.
i will try and change gauge and sender, though not got a clue how to get old gauge out?

It means that rather than ruling out what Station House has to say in favour of what I say, Look at ALL the options.

On the grounds that the vehicle is running ok it sounds more and more like it will be an electrical fault rather than an overheating fault.
 
If you really want to know what temp the engine is running sat, buy or borrow an IR Temp gun - can pick up for about £15 which will be accurate enough to give you peace of mind
 
I don't actually think the senders and gauges match up between the older and newer types. I tried every combination and the only combination of the LandRover gauges that was going to work for me was to drill and tap a hole for the original 2.5 sender to be fitted to my 300tdi.

I ended up with an aftermarket after getting anoyed that my gauge didn't read properly.
 
my disco is over heating on a short run, i have just replaced the head gasket and its runing hot and the heater is blowing cold, i checked the water pump and the impella was broke so i replaced the pump with a new one but its still over heating there seems to be no fluid flow thought the engine, i have blown down the pipes and the water starts to flow and the heater works for that moment, the water in the filler tank is cold, i cant understand it. Any one there with any clue to why this is!!!!
 
Could be a big airlock somewhere.

I would take the back heater hose off the engine block, and fill the system till it pours out of the engine block at the back. Then I would refit the pipe and start to fill from the stat housing till it's full, refit the plug and then start to fill from the header tank.

Start up and let it circulate till you can feel hot water being pushed into the heater matrix and returning, this lets you know you have the block/head full and it's pushing water round the system.

These engines can sometimes be a pest to fill if you have filled them the wrong way round and air has got trapped.
 

Similar threads