Mud-club
Vehicle & Technical => Range Rover => Topic started by: lizzylolly on May 08, 2009, 14:04:56
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Just bought a 2002 P38 4.6 V8 with Pro Mulitipoint LPG Conversion that overheated on the way home one night.
Everything seemed to be OK, all ran fine except it very suddenly threw all the coolant. Owner has said since that it used a little coolant every so often. A LR RR engineer got me on my way explaining that all should be fine and ever since it has been OK, perfect in long traffic and hard fast journeys. But it seems to drink coolant at a pint a day, temp is fine, no leaks and no excessive pressure in the header.
Am I staring down the barrel of Despair's V8 gun?
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Possibly.
Does it start up fine or run a bit rough? does it steam when it's first started? Does it use the same amount of water no matter how far you drive?
Depending who you believe the 4.0 and 4.6 suffered differently from water loss problems. The 4.6s were meant to have the better blocks, selected by testing the material thickenss but then others say that the electronic controlled gearbox causes more heating issues in the liner by keeping the bigger engine in a higher gear to maintain economy.
Anyhoo, you could try a can of gunge in the coolant, don't just tip it in though it needs to be well mixed, perhaps add it to the rad instead. Try K-Seal or cargo seal.
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May sound strage but what lpg system do you have as my old v8 disco started to lose coolent could find no leek anywere. After much time and effort found that the evaporator unit had split inside and was leeking water into the gas system. new evaporter and problem sorted.
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careful when you use K-seal, or you can say bye-bye to the engine altogether when it may not have had a problem in the first place. have you checked everywhere for leaks? hoses with pin [ed - prod with a sharp implement] holes in etc. you will only see them when the cooling system is up to pressure and the engine is revving. my old rangie would lose water on a decent run, but short distance as it never got up to proper pressure would be fine!
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hoses with pin [ed - prod with a sharp implement] holes in etc. you will only see them when the cooling system is up to pressure and the engine is revving.
Pinholed hose can be even more devious than that.
Twice in my life, on different cars, a mystery leak has been down to a tiny split in a hose. Start from cold, no leak; warming up, no leak - the cold hose was stiff enough to keep itself sealed. Full temperature and pressure, no leak - pressure and combination of shaped curvey hose keeping the split sealed. Switch off and wait ten minutes .... dumps a half pint and then reseals with no trace except the puddle. But only sometimes. Lil sod to catch that!!
Suddenly ejecting coolant could be a pointer to the LPG as already suggested - in some failures, gas pressure can be applied to the cooling system. Clue - very hard hoses and header tank venting.
Bubbling in the header is indistinguishable from 'normal' gasket failure etc, the hot water seems to absorb the smell component of the gas.
Slight reluctance to crank on morning start-up can indicate leaking into a cylinder. Pull the corner plugs (1, 2, 7, 8) and look for rust or steam-cleanliness. Headgasket hopefully. Leaks into the other cyls are probably liner issues.
Does it smell of antifreeze under the bonnet? Seeping radiator. In the cabin? Heater O-rings. Misting windscreen? Heater matrix. You got to seek all the clues you can.
Be aware you might have a combination - for example an LPG failure pushes out water until its low enough to overheat, then severe overheating is followed a couple of weeks later by head gasket failure, just as night follows day. Often a V8 with water problems will need more than one fix because of knock-on effects.
cheers, Ross K