Losing Coolant, Stumped

[chrisall]

The old NP is losing coolant, but I'm at a loss to understand why/ where. I can do a 200km run and it doesn't use a drop but a10km each way commute and the expansion tank has dropped a cm or so. There are no signs of drips underneath, carpet is dry, doesn't overheat, no signs of water in oil or visa-versa, no significant steam from exhaust.

Waterpump, o-rings, heater hoses, coolant hoses all changed when I did the cambelt maybe 30k ago. Radiator was new around that time too. I've flushed the system and put in 2 bottles of K-Seal, still no joy. I've just bought a cooling system pressure tester off ebay and will see what that shows!

[NFT5]

Sounds like a head gasket, to me. At this stage, minor, so you won't notice anything coming out of the exhaust, but can turn real bad, real quick.

[ROBBIE J]

For what it's worth I had similar coolant losses & it took me a few weeks to find it, front top engine small coolant inlet hose, clamp was weak - small weep , probably vapourised from engine heat as it dripped, I'm not sure if yours is similar as the the 6g74 v6. Mine hasn't lost any coolant since I replace the hose clamp. In a way I'm glad it happened, because I spotted one bolt just dangling off the power steering pump pulley, ready to wreak havoc. Wasn't tightened to spec & so it vibrated loose. Phew, good save. Good luck with it, don't panic yet 🙄👍

[erad]

You probably are already doing this, but just in case... It is important to check the coolant level in the radiator WHEN THE ENGINE IS COLD. Simply looking at the overflow bottle is not enough. If you have a blown head gasket, leaking gases will build up in the coolant system and push excess coolant out into the overflow bottle. Under bad conditions, coolant will eventually escape from the overflow bottle, and not enough coolant will be drawn back into the engine. Everything will look OK when you look at the level in the overflow bottle, yet the radiator top tank could be empty. My old Range Rover had a head gasket blown, and one day I found the overflow bottle full, despite the levels being 'normal' the day before. You have to check both the radiator and the overflow bottle.

[Kingmarz]

You’re going to regret putting 2 bottles of K Seal in your engine.

[RyanPJ]

For what it's worth I had similar coolant losses & it took me a few weeks to find it, front top engine small coolant inlet hose, clamp was weak - small weep , probably vapourised from engine heat as it dripped, I'm not sure if yours is similar as the the 6g74 v6. Mine hasn't lost any coolant since I replace the hose clamp. In a way I'm glad it happened, because I spotted one bolt just dangling off the power steering pump pulley, ready to wreak havoc. Wasn't tightened to spec & so it vibrated loose. Phew, good save. Good luck with it, don't panic yet 🙄👍

Okay, we'll take a look at those spots we work on my friend's new Pajero. The previous owner can't find it. We have to finish the installation of the suspension and xd wheels on the pick-up truck first before we can clear the garage.

[ROBBIE J]

Let me know how it goes.... hopefully it's a minuscule weep 😊👍