Range Rover Classic 300Tdi water temp issues

Range Rover Classic 300Tdi water temp issues

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EIFHS

Original Poster:

4 posts

46 months

Sunday 24th January 2021
quotequote all
Hi Everyone.

I have recently had installed a remanufactured 300Tdi engine and gas flowed cylinder head, new turbo, radiator, all the hoses, thermostat, water pump, viscous fan, belts (you get the picture) very pleased with the smoothness and power. Turner Engineering supplied all the engine bits, very impressed with their service.

So the problem i have is that as the car warms up some slightly warm air comes out of the heater, then as the car reaches normal operating temperature the heater goes cold again, if I brake hard or corner or go up/down a hill it starts to provide heat and will normally continue to do so.

One oddity last week i was driving along at 05:00am on a level road 50 mph and suddenly the temp gauge rapidly increased towards the red zone, I backed of the throttle and it came down a little so i pulled up, checked under the bonnet and released the header tank cap and it was under pressure but not massively so, i restarted the engine and the temp gauge rapidly went back to normal, prior to this heater was cool afterwards it was warm.

I have read most of the threads about these issues and my garage is familiar with working on Disco, LR and the like, we had planned to replace the 3 way pipe that sits under the header tank, but FF sent the wrong one, from what i understand that pipe allows air to bleed from the top of the rad and the top of the thermostat housing (could it cause this issue?) since we manually filled the heater matrix up before reconnecting it to the system it is better, but I still don't think the heater is giving it all, at least not all the time, my big worry was the overheat event, I can't say it wasn't a false reading but all the sensors are also new?

Again we were going to replace the thermostat again at the weekend, but that was also the wrong one!!

Its only done a 110 miles since new engine, so early days and apart from that very brief temp excursion the gauge is rock steady at about a needle width below half way.

Any thought and tips most welcome.

Thank You


camel_landy

5,081 posts

190 months

Sunday 24th January 2021
quotequote all
Don't trust what the gauge tells you!

The response you're getting on the temperature gauge, is exact same response you get with a faulty earth. You may well save yourself a LOT of time and effort by getting an IR thermometer onto the thermostat housing and double-checking. (I had something identical with my 300TDi... 2x head gaskets, 2x thermostats, 2x batteries and a new radiator later, I traced the fault to a poor earth, fixed with a short length of cable.)

As for the heater... That sounds like an air-lock in the system.

HTH

M



100SRV

2,175 posts

249 months

Sunday 24th January 2021
quotequote all
camel_landy said:
Don't trust what the gauge tells you!

The response you're getting on the temperature gauge, is exact same response you get with a faulty earth. You may well save yourself a LOT of time and effort by getting an IR thermometer onto the thermostat housing and double-checking. (I had something identical with my 300TDi... 2x head gaskets, 2x thermostats, 2x batteries and a new radiator later, I traced the fault to a poor earth, fixed with a short length of cable.)

As for the heater... That sounds like an air-lock in the system.

HTH

M
My thoughts too.

EIFHS

Original Poster:

4 posts

46 months

Monday 25th January 2021
quotequote all
When you say faulty earth are you talking engine/chassis to battery or chassis to engine? in which case where is it please.

Ta

Bill

54,162 posts

262 months

Monday 25th January 2021
quotequote all
100SRV said:
camel_landy said:
Don't trust what the gauge tells you!

The response you're getting on the temperature gauge, is exact same response you get with a faulty earth. You may well save yourself a LOT of time and effort by getting an IR thermometer onto the thermostat housing and double-checking. (I had something identical with my 300TDi... 2x head gaskets, 2x thermostats, 2x batteries and a new radiator later, I traced the fault to a poor earth, fixed with a short length of cable.)

As for the heater... That sounds like an air-lock in the system.

HTH

M
My thoughts too.
Glad it's not just me. biggrin

camel_landy

5,081 posts

190 months

Tuesday 26th January 2021
quotequote all
EIFHS said:
When you say faulty earth are you talking engine/chassis to battery or chassis to engine? in which case where is it please.
It could be anywhere.

It could be battery to chassis... Chassis to body... Connection to instrument cluster...

I'm not 100% sure of the RaRo setup but on the Defender, the battery -ve is connected to gearbox casing. It then relies on having an electrical connection through the gearbox casing, bell housing & engine block. This is great when out of the factory but as soon as you split any of those joints (eg: new clutch) and get grease etc across the joints, then you're knackered!!

The long and the short of it is that you're going to have to arm yourself with a multi-meter & wiring diagram and go hunting.

M