What is an acceptable coolant temp for a Defender 300tdi?

[86mud]

Hi all

Since installing a VDO temp gauge in my 1998 300tdi Defender 130, late last year, I have been really watching the water temp fluctuate.

During the heat SE Qld had in January, my water temp was sitting at 100 Degrees on the highway on the flat and at any hill temp would climb to 103-105. Even got to 110 going up a step long hill (Landsborough to Maleny)

Around town it sits about 90 degrees

So this week I installed a new radiator (old was not leaking but was starting to break down and probably clogged), new viscous fan and a new air con thermo fan (fitted a larger 12" Davies Craig) and new coolant. Water pump, thermostat was replaced 12 months ago.

So went for a burn last night around the streets and still temps are sitting at about 90 degrees on flat at 60kms and climbed to 93 going up hill. I will go for a burn down the highway tonight to see what the temp does.

Is this normal for a 300 tdi? There is nothing in front of radiator apart from insect screen. My truck does weigh 2.8t empty and running 285/75 MTZ tyres

Thanks

[ROMAROVER]

Reports in disco 1 section also tell of little improvement so any other feedback would be appreciated, my disco runs around town high 80,s to low 90,s, slow long hills will go to low 100, but cools to normal when descending, LR gauge never moves. temp measured at rear cylinder head.

[uninformed]

One of the biggest issues, as being reported here quite a few times, is air flow. The engine bay of the LR are not good at flowing air I.e. it dams up inside and air struggles to pass through the radiator.

[DeanoH]

Isn't there someone on here that successfully put a vent in the LHS guard to improve engine bay air flow and temps ?

Also, it may be worth having your old radiator 'top' tank removed and decrease the bypass hole size to allow more coolant flow through the radiator.

Deano

[86mud]

I have a vent cut into the left hand guard. Might look at venting the bonnet on the sides somehow, or on top of the bonnet. Anyone done this?

I do have the spare wheel mount in the middle

Old radiator was cactus. So a new one was purchased. Alloy core.

Thanks

[rover-56]

I have a 300tdi Defender that has that rubber seal at the back of the bonnet missing. I noticed a lot of hot air exits there at the rear of the bonnet.
Might be useful to remove it if it is still fitted.

Not really sure why it has to be there? maybe keeps the hot air away from the fresh air vents?

Terry

[roobar_and_custard]

I have seen defenders with bonnet venting added (round holes) down the sides of the bonnet towards the rear (per attached).
I had a series rover which had louvre vents on the top of the bonnet.
No idea how well any of these work...

My 200Tdi "overheated" for a while, I recored the radiator to no real effect, but then changed the earthing strap on the engine - issue fixed!
Worth a try?

Also, the temps you state aren't really that hot. The engine should hold 90degrees(ish) depending on your thermostat, but when pushed hard temps into the 105degree range shouldn't be a problem, but probably an expert should jump in here.

[86mud]

I think I have vent envy! Just searched on Serge's LH guard side vent and my vent would be a quarter of the size!

So.....grinder time!

Will try this first

Thanks

[ajge]

Hi
My 96 130 new vdo gauge and sender, sits on 80 to 83 for general driving. Max I have seen is 93 on a 40 deg day up a long hill. These temps are confirmed with a sensor bolted to the thermostat housing.
I have removed the air-conditioner thing from in front of the radiator tho.
Regards
Andrew

[uninformed]

I think I have vent envy! Just searched on Serge's LH guard side vent and my vent would be a quarter of the size!

So.....grinder time!

Will try this first

Thanks

If I was doing it again, I would make the bottom go a bit lower. There is room and no reason not to.

Another member here did wool pile testing and the bonnet is pretty much no good for venting hot air out.

For air to move through the radiator, it must be able to enter and exit. A custom snorkle would also allow the right side intake (300 Tdi) to be used as a engine bay vent.