Now that I replaced the leaking water pump, I'm facing another issue. There's a very small coolant quantity slowly escaping from the expansion tank cap. It appears that some quantity is being let out at some point but not continuously.
I replaced the cap with a spare one I had but it doesn't make any difference.
Due to the previously leaking water pump, I have developed the habit of filling up the tank a little bit more than what is indicated as "full". Specifically to the point that it just covers the indicator's horizontal bracket / guide. Which gave me more time between refills and a level reference. Both caps, the one original to the car and the newer one are of the 140 marking.

Am I actually causing this by overfilling? Are both caps bad? Or are they incorrect and should be using a 200 one?

Thanks

Ask Robin at Duckworths to check but I thought the 140 cap was only for the first couple of years, IIRC yours should have the 200... I maybe wrong but worth a check...  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
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I'll definitely ask around to make sure I have the right cap fitted.

Thanks.

I agree with Pete.

LR changed to the higher pressure cap and a different cooling system design on the M62 V8 around 2004. You'd have to supply your VIN number to a LR dealer to obtain the correct cap for your car.

Some web sites claim the cap is the same for all 2002-2006 vehicles (when Jag engines came in) - That's simply incorrect.

Not only did the cap's pressure rating change from 140Kpa to 200Kpa (20psi to 29psi) , but the cooling system design also changed (different thermostat housing, some pipework changes as well around the water pump).

BMW / LR brought about the changes to run higher pressure and coolant temps in order to decrease emmissions.

Some of the guys on the Bimmer forums change their cars to run the 140 Kpa system as it's generally thought to be more reliable and less likely to blow hoses (especially the heater hoses which can be a bit suss).

Jon 1992 RR Classic 3.9 efi Vogue
===================
Both my fatties now gone...
Previous: 2011 L322 4.4 TDV8 Vogue SE /// 2002 L322 4.4 V8 HSE /// 2009 Discovery 3 2.7 TDV6 XS /// 2004 Defender 90 TD5 /// 1993 110 V8 Snatch Landrover /// 2005 Discovery 3 2.7 TDV6 SE (Aus) /// 1990 110 Isuzu 3.9 County (Aus) /// 1976 Series III Trayback (Aus)

Thanks for the advice, much appreciated

Just spoke with the local dealership and they said the 140kpa is the correct cap

Vin # SALLMAMA44A1XXXXX

By the way, just noticed a very slight leak from the below quick coupling

Click image to enlarge

what thermostat have you got in it
mine is a 2005 and had a 105deg thermostat i think it was, i changed it to a 85deg i think it is
a lot of people have done this, it helps with over heating and takes the strain off the system with the 140 cap RR 2005 4.4 petrol
Any spelling mistakes are the fault of spellchecker
Previous MG J2, CITROEN light 15 x 2 gone unfortunately
Present MERC 180e, RANGE ROVER L322, JAGUAR XJS, MERC 280SE, MG F, JAGUAR S-Type 6v 2003, jaguar s-type 8v 2004, Ford Cougar

When I replaced the pump, I also replaced the thermostat. I used the 105 Deg., identical to the one removed.

Do your Range Rover a big favour and fit one of these to yours, especially as you are in a hot place...

Item here...

https://www.ebay.co.uk/itm/80-C-Thermostat...SwlzVa19e6

A good thread here..

https://www.fullfatrr.com/forum/topic39362.html

 Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Hey Pete,

Thanks for the tip. I had been thinking about this mod for quite some time.
From page 3 of the thread I understand there's an 88 Deg. direct fit Behr thermostat, am I getting that right? If yes, I could just swap it out on Monday.
I should have done my homework as it's less than two months since I changed the thermostat along with the water pump.

The original fit ones were hard to get hold of and very expensive when I fitted the kit...

It's very well made, fits perfectly and uses very cheap thermostats which you can change should you need to...

You have to be careful with the lower temps as you may go too far and the fuelling won't go into closed loop.... not good..!!

 Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Considering I paid 100+ euros for the standard one I just replaced, I'd say that cost isn't an issue. Even at that price, It isn't something you change very often. What really matters is having an improved system running within spec / manufacturer tolerances.

i fitted a BMW one, cant remember what model it is off RR 2005 4.4 petrol
Any spelling mistakes are the fault of spellchecker
Previous MG J2, CITROEN light 15 x 2 gone unfortunately
Present MERC 180e, RANGE ROVER L322, JAGUAR XJS, MERC 280SE, MG F, JAGUAR S-Type 6v 2003, jaguar s-type 8v 2004, Ford Cougar

D3Jon wrote:

LR changed to the higher pressure cap and a different cooling system design on the M62 V8 around 2004. You'd have to supply your VIN number to a LR dealer to obtain the correct cap for your car.
<snip>
Not only did the cap's pressure rating change from 140Kpa to 200Kpa (20psi to 29psi) ,

Haylands wrote:

You have to be careful with the lower temps as you may go too far and the fuelling won't go into closed loop.... not good..!!

p38arover wrote:

It appears the 200kPa cap was fitted up to VIN 1A001049 and the 140kPa cap thereafter.

PCD000070 (CAP) [ (V)1A001050 - ]
PCD100200L (CAP) [ - (V)1A001049 ]