Thread: Disco 1 300Tdi gets hot when towing up hills.

Hi Sean
How much country driving(BUGS) or off-roading has it done??? If it has done a fair bit with mud/muddy water chances are the matrixs of the air-con,intercooler and radiators are clogged and need a good clean.
Other than that the radiator could be clogged internally with scale,this is a radiator shop visit,remove a tank and rod the cores out.
I would definately look into it BEFORE your holiday,there is nothing like an overheated motor to ruin a good holiday,it is good insurance.
I would also have the radiator pressure tested to ensure there isnt an internal water leak inside the motor.
Good luck
Andrew

do the external radiator core clean thing, then pull the thermostat, the condition of this will be a devining rod for the condition of the radiator... Which is why I always replace mine every time I have the radiator cleaned out or worked on..

Id check the belt slip over the waterpump/fan pully then be thinking that if that was good your having flow issues in the radiator.

If your unlucky this can be a precursor symptom to a head failure....(playing devils advocate here)

Mine has a sticking thermostat (it's stuck open) but my 300Tdi Disco's have always run at 1/3 or less, even in deep sand on a hot day (Stockton beach where a mate in a V8 D1 cooked his ). In the snow it actually gets colder doing hard work.

I'd look at the thermostat and maybe check to see if you're holding pressure. My cap on the overflow tank has just started leaking, so you may be losing water there.

mine used to sit @ or around the 95-97 degrees on the VDO temp gauge and go over the 100 degrees on long hill or towing, the previous owner said everything was good and it always read 10 degree to high, i checked with an infer red gauge thing and he was right.

i ended up having to do something when the gauge starting going up and down by 30-40 degrees when i put the indicators on and go to about 120 degrees when i put the head lights on

i changed the thermostat and fitted a mechanical temp gauge, now she runs 86-88 degrees with out load and goes upto 92-93 with big load going up hills

How may km has the car done? Our TDI was doing the same until the water pump bearing went. It had done 140k. It was an easy job to replace and good insurance. At the same time I had the core cleaned but the radiator shop said it was in good nic

also consider the fan clutch, even at 80+km/h speeds. A bloke in a 'fender had the same symptoms as you, someone convinced him to swap out the fan clutch (even though it seemed to test OK) and that's what it turned out to be, much to my surprise, as I thought ram air would take over above 50-60km/h. Appears that a lot of cars have poor underbonnet venting, relying on the fan to push the air out of the underbonnet area.

Be careful when replacing the t/stat. Wrong part #'s are listed in most aftermarket catalogues. http://www.aulro.com/afvb/showthread.php't=25269&highlight=t%2Fstat

...also check the electrics!

You're making the assumption that the gauge is actually correct. You might want to borrow a laser thermometer & jump out to check the actual temp rather than trusting the gauge.

Mine used to 'overheat' quite badly. 2x head gaskets, 2x batteries, 1x stat, sender, etc... eventually found that the 'overheating' was due to a missing engine earth strap. Fitted a new one & everything was fine. It also cured the warm starting problem I had.

M

ditto what Camel Landy said. Instrument earths are notorious on Landy's, and the temp guage doesn't have a good reputation for accuracy.

Part of the reason I replaced my guage with a mechanical one was that the headlights and wipers affected what the guage read. I was also having the temps climb (not badly) going up hills when raining ! Turn the wipers off and it settled back to 'normal'. Fitted a VDO mechanical guage and no more problem.