Hunter

Hey guys got a bit of a prob. with my 6 cyl EL and I hope someone might be able to shed some light on it... anyway its done about 149,500 km and has been drinking coolant for a while now. It had been eating coolant at a slow and steady rate (about 200 ml a week or so) up until I replaced the radiator surge tank cap. But now its gotten much worse and I am basically having to bring the surge tank back up to halfway after every drive. Both caps are completely identical in both specification and brand. The old cap was quite loose and the new one is a fair bit tigher to screw down. The coolant disappearing isn't the only problem - its also idling somewhat rough though the tacho says its idling around where it should be for both D and N respectively. Coolant eating aside, I forgot to mention that whenver I remove the surge tank cap now, there's quite a lot of air pressure in the tank - it's like opening a soft drink bottle. And there's a bit of gunk in the surge tank too, looks like dirt floating in it. Also, no emulsified oil/water in either coolant or sump.

Early this year I had the water pump, thermostat housing, thermostat, upper and lower hoses, and coolant replaced by my mechanic. This wasn't too much of a prob. because I could actually see where the coolant was squirting out into the engine bay. The current problem worries me because I can't see/smell the coolant whereas when it used to leak before the pump was changed you could smell the coolant burning in the engine bay. Couple that with the rough idle and I'm beginning to feel my wallet glowing. I purposely put about a grand away in case the head gasket shat itself and I am hoping there is some other explanation for these problems. Anyone able to help?

Cheers,

Hunter

reece1

i think your thoughts are right, these mtrs pop the top off the headbolts and loose tension on the cylinder head.(the head of the bolt cracks off at the top of the boltshank VERY COMMON) putting a new cap may have retained more pressure in the cooling system forcing water into the cylinder.put the cap on the halfway mark and see if your symptoms change.these heads also corrode the water jacket around cylinder 6 as well.when the head is done new headbolts MUST be fitted. a way to check yourself is look for bubbles in the cooling system. when the vehicle is hot pull the plugs out and keep in order and compare to each other, sometimes the water can steamclean one or more.look down plughole for water in bore while radiator is hot with cap on under pressure, and finally milky creamy substance under cap but your symptoms sound like water to combustion chamber leak and will not show this symptom. hope this helps.

keep research

Chech the side of your engine block for water stain. If head gasket is ruptured you will see a white stain coming from somewhere along the head gasket underneath the exhaust manifold. Usually this side. But could be the other side. Or look for water and inhibitor stain somewhere else.

maybe suggest to pressurise your raditor. Get a pressure tested and try to force the water out of the hole (wherever it is). I have used an old radiator cap and pulled the guts out of it and fitted a car tyre tubeless valve and pumped up with a tyre pump. Make sure you attach a pressure gauge and stop at about 15 psi. This should be safe enough and force water out to find where it is escaping from. Sounds like external if no indication of water mixing with oil or vice versa. let us know how you go.