im loosing coolant about 5 ltrs in 3 weeks. its concerning. i dont have milky white in the radiator and no water in the oil so i dont think its the head gasket nor can i see any visable leaks. the water pump has some crusty crystals of coolant on it could this be the cause. also there is some minor rust colour in the radiator.

please help me to find the cause.

Personally I wouldn't really call 5litres in 3weeks a "slow" leak. To me that's a fair bit of a leak.

The water pump might be "weeping" (leaking through the internal seal), the crystals you describe sound like what I had for years, I knew it was weeping and that the water pump needed replacing, but I was losing nowhere near the amount you are (a few hundred mils a month or so), so as long as I kept on top of the losses then it was business as usual until I replaced it at timing belt time.
Yours sounds rather more urgent. Don't know the 4cyl setup, so don't know if it's easier or harder than the 6; with the 6 you basically have to take off all of the timing stuff, so may as well do the lot in one hit.

[EDIT] Just checked the service manual, and if I'm reading it correctly then it's fairly straight-forward, not really anything else involved, just the pump, radiator, and associated hoses. Could be wrong though.

have you put a piece of cardboard under the car or the like to see where it could be leaking from? or at least the general area

is there any bubbles in your radiator?? should fill it up and do what tufftr said with a sheet of white paper or cardboard to check for where it's leaking. when was the last time your system was flushed. maybe it's to old and instead of working it's just boiling and draining out the overfill bottle??

ill try that smooth 2 but i cant do the cardboard or paper i have to park in the open on a gravel driveway so anythink thats white or towels or paper gets soaked.

One thing you could try doing is run the car idle from cold to operating temperature. As the car warms up keep an eye on all the hoses and connections and look for any leaks. Keep an eye on the exhaust too, as it should only remain steaming until the car is about halfway to operating temperature. If it continues steaming beyond this, it is likely you have either a leaky head gasket or a cracked head or cylinder block. Check each of the spark plugs too and if there are any rusty ones, it is definitely an internal leak. Also replace the radiator cap and check the overflow tank hasn't got a perished rubber seal around the cap, as these items can cause coolant loss.

For such a significant leak I imagine there is an internal leak somewhere within the engine, as a damp connection around a hose won't lose that much water.

the overflow bottle is dodgy round the top and the radiator cap seal could be crap. doesnt steam a lot after starting only to half way to op temp and spark plugs are fine too.

I had an issue with mine with a deteriorated cap on the overflow tank, and I found I was having to refill the bottle and top up the actual radiator on a weekly basis. Got a new cap for the overflow bottle, and haven't had a problem since! Only thing I can put it down to is steam was escaping from around the seal...

Radiator caps are fairly cheap and simple to replace, so I would recommend changing that. If you are still finding issues with leaks, I would start suspecting internal issues within the engine - maybe a coolant leak into the oil or a leak that develops when the car heats up, which will obviously not be obvious (as it would be evaporating nearly instantly after leaking).

Not much more I can think of where it could be leaking... although - do check the heater core too, as it may be leaking and coolant just flowing out the drain hose. Unlikely, but still a possibility.

I had a problem like this, only I found out the cause within a week ('cause 75% of my coolant ended up on a mates driveway hehe). Check your Thermostat housing. It may be corroded. Mine had a hole in it about 0.5x0.7cms. That bastard let out enough coolant that I almost overheated in the drive through at the local Reddies. Check the housing, if you've got bad corrosion get a full cooling system check, because you've probably pumped corrosion and sh!t through everything and that never leads to nice things.

came back from mitsu and prognosis not good the welsh plugs are starting to leak and the water pump is packing it in. all up mitsu want 2 grand to fix:cry:

No way, DIY it. Save you mucho pesos hombre.

Water pump should only be about $60 or so, and is an easy DIY job. Welsh plugs I'm not sure about, but I have seen them at shops for fairly cheap. Not sure how you would go about replacing them though... but either way - definitely nowhere near the $2k mark!!! :shock:

Water pump should only be about $60 or so, and is an easy DIY job. Welsh plugs I'm not sure about, but I have seen them at shops for fairly cheap. Not sure how you would go about replacing them though... but either way - definitely nowhere near the $2k mark!!! :shock:

yeah, the plugs are cheap, its the labour that kills you. from memory, when they did my old 4pot, there is three or four just behind the extractors, so you can guess how fun that job would be...

its the rear ones that are starting to weep. can you just take off the inlet manifold and do the rear ones?

You could try, but there isn't much room to maneuver around there. Would not be very easy trying to see what you're doing either, which would make it even harder again. Frankly I would agree with just removing the whole engine - that way you can get to all parts of the engine quite easily and any problems will be quite obvious.

yes there are 6 small welsh plugs 3 above and 3 below the balance shaft casting
and one 70 mm at the starter motor

engine out is the only way to fit the rear engine ones correctly

how to replace welsh plugs

measure the ones you need

drain coolant from block

remove extractors/ exhaust manifold

pin punch them inwards

then extract with pliers or screwdriver or other

look for socket or pipe the right size for welsh plug

apply to side of plug stag or gasket goo

tap in evenly and slowly till flush with block

move to the next one

on the 4 cyl

gearbox has to be removed to do the blocks end one

one in the head is easy


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