Last week, I did a valve job on my truck and everything went well. Although I kept noticing the expansion tank was low on coolant. I would add about half a litre or so every day. No signs of coolant in the oil or visa-versa.

I've been checking for leaks like crazy, but have been unable to identify any and it's driving me crazy. Finally, when I was coming out of a high school reunion yesterday, I noticed coolant was dripping from my skid plate, underneath the engine. I wasn't able to go under it and check right there and then, so I drove home and put the truck on ramps to go underneath, remove the skid plate and check - no sign of any leaks.

The weird thing is though, I can hear liquid flowing behind the dashboard. I reckon if the heater core was gone, coolant would leak from behind the engine.

The water pump has 70,000 km (43,750 miles on it), and I reckon if it was the water pump, it would leak every time I kill the ignition. All the hoses and everything else are tight and there's no sign of any leaks behind the engine. I've also checked the obvious hoses, etc and I still go nowhere.

Any other ideas as to where I could check? Mechanic recommends stop leak, but having spent $800 on the truck, I'm not keen on using a $2 stop leak to fix the problem. I want to solve the problem right from its core. Thanks!

 

you hear coolant swishing because the system is low and has air in it.


and i cant really help without knowing the year and engine.

 

Sorry, it's a 2000 Pajero/Montero with a 12-valve 6G72.

 

could be the o-ring that goes on the pipe from the water pump is leaking. or misaligned. when you took the heads off did you take the pipe off. that pipe runs in the middle of the block under the intake. o-ring must be replaced, can leak and not be seen.