coolant leak in mornings

Hey, I havent been able to pinpoint it yet as it only happens in the mornings and its dark when i get up, it is dripping from the rear of the engine/bulkhead direction. I idled it yesterday for 40 mins and then went for a foot to the board 15minute spin , the pressure had built up in the coolant pipes and no leak at all, then this morning the drip was back and it took 2litres to top up. any ideas? gonna have a good look this weekend but thought i'd ask on here first. Cheers.

Petrol or diesel?

mickdundee said:

Hey, I havent been able to pinpoint it yet as it only happens in the mornings and its dark when i get up, it is dripping from the rear of the engine/bulkhead direction. I idled it yesterday for 40 mins and then went for a foot to the board 15minute spin , the pressure had built up in the coolant pipes and no leak at all, then this morning the drip was back and it took 2litres to top up. any ideas? gonna have a good look this weekend but thought i'd ask on here first. Cheers.

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Sounds like its coming from the expansion tank overflow hose. Over pressurising. Need a sniff test to see if its head gaskets. Also check waterpump and viscous fan coupling. If you've changed the coolant recently could also be an airblock.

petrol. it only leaks when the engine is cold and the system has minimal or negative pressure, it will happily drive for hours with no loss then the next day, the dreaded drip. water pump and fan ok. i'm thinking that it the pressure is holding a hose join water tight but then when cooling down and there is negative pressure in the system a hose looses its seal, but which one?

mickdundee said:

petrol. it only leaks when the engine is cold and the system has minimal or negative pressure, it will happily drive for hours with no loss then the next day, the dreaded drip. water pump and fan ok. i'm thinking that it the pressure is holding a hose join water tight but then when cooling down and there is negative pressure in the system a hose looses its seal, but which one?

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I don't know the V8 but I think there is a little hose round the back of the block. Also core plugs are a possibility.

There's no coolant hose at the back of the V8. Closest would be the heater pipes where they go into bulkhead on drivers side. Is the drivers footwell dry?? Where exactly are you noticing the dripping water?

kevwill said:

There's no coolant hose at the back of the V8. Closest would be the heater pipes where they go into bulkhead on drivers side. Is the drivers footwell dry?? Where exactly are you noticing the dripping water?

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yea drivers side bulkhead direction, footwells are dry as far as i can tell and its dripping on the drive. heater pipes sound promising.

mickdundee said:

yea drivers side bulkhead direction, footwells are dry as far as i can tell and its dripping on the drive. heater pipes sound promising.

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Does it have LPG fitted? If so the heater hoses may have been tapped into and piped to the LPG.

mickdundee said:

yea drivers side bulkhead direction, footwells are dry as far as i can tell and its dripping on the drive. heater pipes sound promising.

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If the 'o' rings from heater hoses to matrix need replacing you'll have a wet/damp patch in the drivers footwell, so doesn't sound like that. Check the rubber hoses where they join the metal heater pipes on drivers side bulkhead direction. Also after running the car up to temp - just double check the black plastic overflow/pressure pipe from the expansion tank - because this will be in the same area; 2 litres is quite a bit to top up (out the 11 ltrs total) which is why I ask. Let us know how you get on.

it has lpg so thats anther thing to check, i didnt even know the gas took a water feed and i had read about the heater o rings but the leak is for certain outside as i can see it in the afternoon in the form of a puddle. i downloaded the rave so i'll check all the coolant hoses at the weekend but keep ideas coming, all good so far.

You might find it easyer to check for leaks, once you have turned it off and the heat and pressure whilst cooling will let the water out rather than cold to hot with no pressure