ok guys and girls have a slight problem. Yes I have searched threads however they have basically said in relation to coolant in the valley that it is the transfer pipe seals. I have pulled it to peaces twice now. First time replaced them with after market seals from Repco.......filled the valley with coolant straight away. Second time used the mitsubishi seal and smeared heat proof silicone all the way around the water pump side and the thermo housing side. Made sure both ends where clear of rubbish and old silicone , when the pipe was placed in it was a nice tight fit , let dry out for a couple of days. There was no coolant in the valley for the first couple of drives but then all of a sudden a little appeared. That was on Saturday then Sunday the amount stayed pretty much the same. However got home tonight and noticed coolant under the car. Lifted bonnet only to find the coolant has leaked out all throught he valley and down the top section of gear box and on to the ground. So at this stage ruling out the seals mainly cause one would think for it to happen twice in the same spot after using the correct seals and a sh*t load of silicone that just not it. Does any one konw if the water pump has weap holes or similiar at the back on the backing plate and has anyone had one leak from there? If the water pump was rooted I would have seen coolant when I removed the timing covers but it was dry as a bone in there. Any help would be great, thanks in advance.

I would check all coolant hoses in that area for tightness and splitting, and look for wet hoses - might be trickling into the area down a hose further away. Possibly the thermostat housing is putting out a jet of coolant when under pressure? Also check the intake manifold bolts for tightness - I might be wrong, but I think coolant runs through some passages in the intake manifold. Are there any welsh plugs near that area? If you are REALLY desperate, try one of the chemical leak sealers in the coolant. Failing all that, I can only suggest that you strip things down and look for cracks in metal parts, and gasket surfaces that aren't flat when they should be.

Another idea is to get the engine up to temperature and the cooling system pressurised, then use a torch to inspect the area. Remove the air box and ducting to get a better view. Good luck - took me two weeks to locate a similar leak - turned out to be the top radiator hose clamp not tight enough - didn't find it until I removed the air box and had a good look - 2 weeks to find, 10 seconds to fix, ho hum! lol

hey mate thanks for the reply. After it leaked the first time I replaced the transfer pipe, lower manifold, plenium, thermo housing and any water related hoses. Coolant is pooling at the water pump end first then filling up the valley and leaking out down the gearbox. Checked the heads when it was apart for any signs of leaking from gasket and no miss in engine to think it is blown head gaskets either.will pull manifold off tomorrow arvo and pressure test the unit to see if I can see where it is coming from that way.Because I have replaced all the bits in that area except the waer pump and it doing the same thing I am thinking it must be water pump.Have thought of using some form of stop leak but it will only stop it for now I want to fix once and for all.

Judging from your avatar, you have a decent looking 3rd gen, so chemiweld or another cooling system stop leak would be a bad idea. It fixes the problem but can also block up your coolant passages and put the motor into a long drawn out and painful death.

Happen to have that problem with my KR. Was the water pump housing corroded where the seal fits. Had to change the Water Pump.

Mate,
For starters if you are going to use Chemiweld might as well just take the car to the wreckers now and save you the towing costs when it dies all together.

There are only 4 places that the coolant can come from in that area
1/Water pump housing - rare but have seen it
2/Water transfer pipe - the metal one that runs from the pump housing to the cross over coolant pipe
3/crack in block - never seen this
4/head gasket - agian with third gen they are a metal gasket and would be very rare

Silicone is a terrible idea on these "O" rings, they should only have rubber greese on them and that is it. If there is a leak you need to find the reason and not guess as it is a lot work to go to only to rip it all apart again.

Forget this starting engine up and running till pressurised, if the leak is that bad it prob wont pressurise anyway. Remove your top manifold, lower manifold and the pipe is there in front of you, borrow, buy or loan a rad pressure tester and pressurise that way, find the leak and you will then be able to fix it. If you do not have access to a pressure tester get a mechanic to do the above to locate the leak and fix it.

You need to find the leak as replacing random parts is not going to fix this unless you see a part that is faulty

+1 what he said above.

Time for a new water pump methinks

Rung machanic today and ordered new water pump and backing plate. It's the only thing left that wasn't replace anyway. There is a seal between water pump and backing plate so fingers crossed should be it. Will take plenium and lower manifold off and pressure test system before replacing pump. that way will be able to see where coolant is coming from.Thanks so far for the imput will let you know what happens.

what hapend to me, is that the seal before the bearing on the water pump went hard and the coolant leaks past teh seal and out the 2 holes on the pulley side of the pump, it then runs back into the valley. Take your timing belt cover off and i bet this is what is happening. run the car and give it a rev when it is hot, you will see atleast one hole, and it willl have water on it.
The reason those wholes are there is so that the water leaks out before getting to the bearing. if you block the holes the holes, the water will dry the bearing and it will make a horrible noise, and possibly cease.
also how many k's has the car done? if it is close to 90 or 170 - 190, i would do the timing belt change at the same time (including crankçam seals.)

ok water pump it is. machinic picked up new pump and backing plate today $120.00 and is fitting it on Tuesday along with timing belt etc.The backing plate has a drain hole in the back and yes it has a seal between it and the water pump and that is what is leaking.Can do the job without taking any top parts of the motor off app. He did one today on a verada.Thanks for all the help guys. Will try and get some pics posted of the car it self soon.

just got back from trip and picked up car from machanic. Backing plate for water pump was leaking. It was coming out of the pump and into the valley. Thanks for your help with this one . Have a great xmas.