D2 TD5 High coolant temperature

Hi all, I have a problem with my coolant temp after replacing thermostat it reaches almost 100*C driving around town 40-70km/h, I went with Dayco one PLE100990 so it should start opening around 82* and fully open at 96*

Car is Discovery 2 98’ TD5 10p Automatic with hybrid turbo running 1.3bar and Eu3 intercooler de-egr and stock exhaust

Coolant was blend using RAVE instructions, I’ve used G13 coolant concentrate with distilled water.

I’ve replaced mine because it was acting up, when I was driving ,out of the sudden,my AutoGauge water temp was dropping to 70*C and slowly going up to 90*C.

Prior to replacing thermostat I’ve cleaned radiator, bottom part was caked with mud now it’s clean. Apart of that I can hear fan working when engine is above 95* mark.

Car is mapped I have EGT gauge around town driving like granny it stays within 300*C.

I have no idea about all the mods, but if you were having issues before and thats all you have changed then maybe its something else.

I would only ask did you test the thermostat before putting it in???

J

Oh and welcome .

marjon said:

I have no idea about all the mods, but if you were having issues before and thats all you have changed then maybe its something else.

I would only ask did you test the thermostat before putting it in???

J

Oh and welcome .

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Thanks so much for replying, I’ve assumed it’s thermostat cause when car was up to 90*C and I was stuck in traffic it was dropping to 70 and going back to 90*C

You mean, putting it in hot water to see if it opens, no I didn’t do that

To me it either sounds like the old 1 was ok ish and the new 1 is duff possibly.

Test the new 1. Well test them both really.

But yes bring temp up slowly so you can monitor when it starts to open and when its fully open.

J

The chemical properties of the coolant mix that you're using are quite different from those recommended for the TD5, which could be the reason why you're seeing this odd behaviour. G13 coolant is based on Glycerin whereas the recommended OAT should contain Ethylene Glycol. Also distilled water is neither required nor recommended for engines constructed from cast iron and aluminium as it promotes leaching of metal ions. Besides the chemical properties such as boiling point, etc. are different from those of tap water.

NPG said:

The chemical properties of the coolant mix that you're using are quite different from those recommended for the TD5, which could be the reason why you're seeing this odd behaviour. G13 coolant is based on Glycerin whereas the recommended OAT should contain Ethylene Glycol. Also distilled water is neither required nor recommended for engines constructed from cast iron and aluminium as it promotes leaching of metal ions. Besides the chemical properties such as boiling point, etc. are different from those of tap water.

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Okay I will change it, guy in store said G13 is OAT so I went with it. Thanks a lot I will change it today

So I’ve found in local store, Dynagel 2000 it’s OAT I will replace it and let you guys know

Sieklo said:

Okay I will change it, guy in store said G13 is OAT so I went with it. Thanks a lot I will change it today

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He's right on that one. In fact, G13 is more "organic" than ordinary OAT since glycerine is a bi-product of bio-diesel and not toxic as ethylene glycol. So although both types of coolant are classified as OAT, they use different antifreeze agents which is what glycerine and ethylene glycol are.

The PEM100990 is cream coloured and opens at 190°F/88°C with a hard spring for a Td5 engine.
The PEL500110 is grey coloured and opens at 180°F/82°C with a soft spring for a Freelander K-series engine.
Both thermostats are interchangeable for V8, Td5, K-series and PUMA engines.
I have the PEL500110 on my Thor V8.

Hi, make sure that the tank's cap is fully tightened and it's valve is not stuck but if it's old don't fiddle with it just replace it with a new branded one. Even if you hear the fan working try to stop it with a rolled up newspaper when the radiator is hot... if it stops you need a new one cos the viscous unit is worn and it has not enough power to cool the engine

Sieklo said:

Okay I will change it, guy in store said G13 is OAT so I went with it. Thanks a lot I will change it today

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G13 is HOAT is a mix OAT and IAT so is recommended for alloy engines albeit with the newer vehicles.
We assume that the viscous coupled fan is spinning as it should.

Hey guys, I’ve flushed out G13 out of the car, and put proper OAT coolant, sadly it didn’t help but when car was up to 95*C on gauge I’ve removed top fan cover and put my hand on radiator and it was only hot close to top inlet in other parts it was stone cold, so my thoughts are that thermostat is not opening at all. I can drive car while the cabin heat is turn to max with fan on max it stays within 90*C to 95*C ( I drove like that back form work)

I will buy the PEL500110, sadly lost the recite for this broken one, that’s lesson learned.

sierrafery said:

Hi, make sure that the tank's cap is fully tightened and its valve is not stuck but if it's old don't fiddle with it just replace it with a new branded one. Even if you hear the fan working try to stop it with a rolled up newspaper when the radiator is hot... if it stops you need a new one cos the viscous unit is worn and it has not enough power to cool the engine

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To be honest I don’t know how old the cap is, but previous owner stated he replaced it shortly before I bought it.
I will do the newspaper test later today and let you know how it ended.

Problem solved, garage that was supposed to do it F.. up but they will fix it for free, thermostat was plumbed incorrectly.

The bypass was plumed to the pump outlet. I’ve found pictures that might help someone that is doing this job for the first time