Mysterious coolant leak

So it’s an L322 4.4 V8 BMW Petrol engine- sentimental so despite age, scrapping is not an option.

Going through coolant every 3-4 weeks with the low coolant warning coming on. Pulled into a garage last week for them to top it up after short 5-10 min drive and coolant boiled out of the reservoir like lava. The temperature gauge never moves above normal.

Done a sniffer test twice for the head gaskets and it’s fine and no signs of coolant in the oil.

Drove it to a relatives 150miles with AA cover in place, the fans on full heat into the cab and windows open. It drove like a dream and no coolant lost.

No warning lights on the dash. But if I do a short 10 min journey without the heating on full she burns through coolant and smells like I’ve driven to France and back.

Mechanics a bit baffled. Any Rangy expert thoughts appreciated.

Poss the common leak at the back of the engine left hand side as you look at it there is a push fit connector. It leaks down the back of the engine and evaporates so hard to find its a cheap part I always carry 1 in the car.

biketeacherdave said:

Poss the common leak at the back of the engine left hand side as you look at it there is a push fit connector. It leaks down the back of the engine and evaporates so hard to find its a cheap part I always carry 1 in the car.

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Thanks but out of interest if it was a leak wouldn’t it leak all the time regardless of when the heating is on. As it drove 100+ miles last weekend heating on full blast to pull heat away from the engine and no coolant loss as a result. Sadly I can’t drive with heating on full whack year round.