GQ using water.

did any thing show up when you presure tested the cooling system.
just finished a head job on a v6 pajero slight crack around one of the inlet valves welded up good as gold now.

There was some slow pressure loss,but nothing I could really put my finger on.
My main concern is that all the plugs were rusty which is why I have asked about a possible inlet problem.

The car runs perfect no comp loss no misfiring no contaminated oil/water,not even over pressurising.

If need be I will strip the lot down but I would prefer not to waste my hrs,or my customers money.

This is odd to say the least. I am not at the stage where I am scratching my head I would just like to save myself and my customer some time.

You could be on the right track with a possible crack in the inlet manifold - if it has a water jacketed manifold. I don't know my way around these vehicles these day. 20 years since I was mechanic.

Try plugging the inlet and outlet hoses on the manifold and pressure test the cooling system again. If the "slight drop" in pressure doesn't happen, then the manifold is cracked inside.

Bilbo

Kik,
If you are sure that the head is ok, which on these is suspect, they do crack, the amount of water you're using suggests something more adoo here, the side plates on the engine corrode they are ally, I'm more or less certain there isn't any water connections in the inlet manifold, if the water was getting into the cylinder at this rate I'm sure there would be evidence of a missfire, I'm assuming this is petrol not diesel and the plugs you talk about are spark rather than glow plugs. The other common failing point is the core plugs on the back of the engine, there is one on the head which can be done by taking the head off unfortunately, or there is the other two one which is inside the bellhousing, this one is evident by coolant dripping out of the gearbox bell housing drain hole, which can get blocked with friction dust.
If you still can't find the leak put a pressure test on the system up to about 9 to 13 psi and look for leaks. The ally fron engine plate can leak between the head and the block again a quick look will tell you the answer. If this is leaking you may have to take the engine out, the seal is a rubber o-ring, the o-ring goes hard and cracks over time. Any emulsified oil, water in the rocker cover? Head gasket or oil cooler rooted.
Well that lot should start you off, hope something helps.

Wow great responces from obviously well educated people thank you so much for your prompt and genuine replys.

Ok let me go through what I have done so far just so you all know what has and has not been done.

Car came to me with water using problem last week.
I diagnosed a leaky water pump bearing seal was gone (this was a non gen pump) I replaced with genuine from Nissan down in Geelong.

I also done a full tune including dizzy cap plugs leads ect ect all genuine (I hate come backs).
I also fixed some oil leaks greased the front end ect.

While I had the leads off and the dizzy cap off I removed the rocker cover and gear and re-torqued the head,head studs were at 40lb I assume from detonation as the car was way advanced when it came here.

This I also thought may have contributed to the water usage.

I did a pressure test at 15 psi and over the period of 30 mins it only lost 4lbs pressure.

So I assumed all was well,I had the truck on the hoist and went right over it and found no water leaks what so ever.

There was slight condensation in the rocker cover,but as this truck is used mostly for short trips this is quite normal.

If there is infact no water connections to the inlet (I haven't looked yet) I will have to pull the head no question.

I am hoping there are as I will disconnect the hoses and give the truck back,and wait and see what happens from there.

Once again guys thanks heaps for the replys.kik

www.autoremedy.com

remove the manifold and leave water hoses connected (if there are any ) . If no water comes out under pressure test . Bet on Head