FFS! Mystery coolant disappearance

[jimmacD]

My 4.4 V8 is running spot on these days.... clasping piece of wood to my chest. No lights, gearbox issues etc.. etc.. it all friggin' works and the RR is a joy to drive again. HOWEVER! For the last couple of months it has been losing about a litre of coolant every couple of weeks? No dash lights, no steam or moisture from the exhaust, no running issues or hesitation, foot wells are dry, heater works well, engine oil is nice and clean and constant level, no puddles or leaks and no gas smells or contamination in the coolant expansion tank? I know these engines run hot and we have had some very hot days in Lincolnshire... but to lose that amount of coolant? Any ideas?

 

[kermit_rr]

Do you have the capability to pressurise the system while it's cold? If you have a leak, it could be landing on the exhaust or collecting somewhere in the engine bay and evaporating without any drips.
These are much easier to spot on a cold engine.
I've got a weak spot on mine i intend to address while I've got the water pump off, i would have had no chance seeing it on a hot engine

 

[tomcat59alan]

Do you have the capability to pressurise the system while it's cold? If you have a leak, it could be landing on the exhaust or collecting somewhere in the engine bay and evaporating without any drips.
These are much easier to spot on a cold engine.
I've got a weak spot on mine i intend to address while I've got the water pump off, i would have had no chance seeing it on a hot engine

What engine do you have?

 

[Colthebrummie]

Check the expansion tank around the cap, if tiny cracks appear coolant can escape unnoticed.

Col

 

[jimmacD]

Do you have the capability to pressurise the system while it's cold? If you have a leak, it could be landing on the exhaust or collecting somewhere in the engine bay and evaporating without any drips.
These are much easier to spot on a cold engine.
I've got a weak spot on mine i intend to address while I've got the water pump off, i would have had no chance seeing it on a hot engine

 

[jimmacD]

I could cobble a pressure tester together. I have a little weeping on my rocker cover and a small water leak could be hidden by that. Gasket, plugs and PCV are on the list so I will be getting up close and personal with the old gal! I changed the alternator last year so that may be my first place to check?

 

[jimmacD]

Check the expansion tank around the cap, if tiny cracks appear coolant can escape unnoticed.

Col

Had a quick look at the cap and around the neck... I think it had a new one last year as I found a spare in the boot? Will have another look see.

 

[Dippypud]

Also dose any suspect area with talc, the leak track will remain after the water evaporates, I had a leak from a tiny wear hole in a heater pipe, the water ran under the gearbox tunnel roof to drip on the floor mid vehicle, drove me mad chasing it for months ...

 

[jimmacD]

Also dose any suspect area with talc, the leak track will remain after the water evaporates, I had a leak from a tiny wear hole in a heater pipe, the water ran under the gearbox tunnel roof to drip on the floor mid vehicle, drove me mad chasing it for months ...

That's an idea, it is a pain when small amounts disappear or you can't find the cause... my aftermarket head unit didn't have any sound, checked boot and there were signs of damp in the amp... stripped, cleaned, re-soldered... it works! Oh no.. it doesn't work... it does work... etc.. Had the unit out etc.. at the point of replacing everything. Purely by chance, turned out it was a lose ground at the ignition switch! Much easier when stuff just goes bang!

 

[jimmacD]

What engine do you have?

4.4 v8 petrol.. Bombay Motor Works.

 

[kermit_rr]

What engine do you have?

Me? 4.0 thor

 

[tomcat59alan]

Me? 4.0 thor

The question was for you mate, for some reason I thought you had the diesel. On which there is an often missed and very expensive O ring by the water pump which cracks.

 

[kermit_rr]

The question was for you mate, for some reason I thought you had the diesel.

Silly boy

 

[Tricky of York]

My 4.4 V8 is running spot on these days.... clasping piece of wood to my chest. No lights, gearbox issues etc.. etc.. it all friggin' works and the RR is a joy to drive again. HOWEVER! For the last couple of months it has been losing about a litre of coolant every couple of weeks? No dash lights, no steam or moisture from the exhaust, no running issues or hesitation, foot wells are dry, heater works well, engine oil is nice and clean and constant level, no puddles or leaks and no gas smells or contamination in the coolant expansion tank? I know these engines run hot and we have had some very hot days in Lincolnshire... but to lose that amount of coolant? Any ideas?

Hi, you said two litres a month, how many miles are you doing to loose that amount of coolant? If there’s no clouds of smoke you would have puddles somewhere surely.
If you do the pressure test take off the under trays because a leak onto them could travel and be harder to trace, I spent a weekend under my sons Jag to find the tiniest leak from the thermostat housing that we identified buy replacing the coolant with fresh pink, it made the task easier in the end. Good luck and keep us posted.
Tricky.

 

[jimmacD]

Hi, you said two litres a month, how many miles are you doing to loose that amount of coolant? If there’s no clouds of smoke you would have puddles somewhere surely.
If you do the pressure test take off the under trays because a leak onto them could travel and be harder to trace, I spent a weekend under my sons Jag to find the tiniest leak from the thermostat housing that we identified buy replacing the coolant with fresh pink, it made the task easier in the end. Good luck and keep us posted.
Tricky.

I haven't been doing many miles since COVID and it is a third car, I ride my bikes when I get the chance or use a diesel for any distance.... 50-60 miles a week if that? I have only put 4k on it in the year or so of owning. There is no damp or smell of damp in the car?

 

[kermit_rr]

I haven't been doing many miles since COVID and it is a third car, I ride my bikes when I get the chance or use a diesel for any distance.... 50-60 miles a week if that? I have only put 4k on it in the year or so of owning. There is no damp or smell of damp in the car?

Fluid can get under carpet and feel dry on top

 

[jimmacD]

I haven't been doing many miles since COVID and it is a third car, I ride my bikes when I get the chance or use a diesel for any distance.... 50-60 miles a week if that? I have only put 4k on it in the year or so of owning. There is no damp or smell of damp in the car?

This is the tenth Land Rover I have owned so I automatically look for puddles etc.. when ever I have stopped somewhere or if the car has sat for a while... tiny drop of oil from the rocker gasket which drips from the front sway bar.... gives the underside some rust proofing! I check the fluids every week and the oil level stays constant. Family are away for the week so I have some time to investigate, got some track rods and brake pads to fit anyway for piece of mind.

 

[jimmacD]

Fluid can get under carpet and feel dry on top

Can do but you can always smell the smallest amount of damp and the windows would mist with the hot weather we have had.

 

[jimmacD]

Fluid can get under carpet and feel dry on top

I'll get it on the ramps next week, give it all a wipe down and check pipework.

 

[Tricky of York]

Well planned, good luck.
Tricky.