engine taking water

[s-rly]

Hi my micra seems to be taking water, not a massive amount but about 10mm every week or so from the filler tank, i cant see any leaks and the oil cap/ dip stick show no signs of mayonnaise and there is no smoke from the exhaust, does anyone have any suggestions what else i could look for? Could a faulty radiator cap cause this by not having enough pressure?
thanks.

 

[Guy]

Mine does the same. Problem is, when the engine's cold, there's no pressure to make it show where it's leaking. When the engine's hot and pressurised, the leak evaporates before you can see it. There's a UV reactive dye you can add to the water I might try. Short of replacing all the hoses, I reckon it's the only way .

 

[pollyp]

check underneath behind engine where the coolant return pipe enters the waterpump. if the o-ring has ever been disturbed it will leak

 

[Guy]

Cheers bud, will have a look tomorrow .

 

[baguete]

Yes, i had to replace that o-ring on all my 2nd hand engines, and water pump too...

 

[will930]

Mine leaks onto gear box and from the short pipe under the dizzy lol