Where is my coolant leak coming from?

[Vilkas]

I have a '94 Navajo w/ stock 4.0L V6. I have a serious coolant leak that I suspect is coming from the lower intake manifold and hopefully not a corroded or cracked one. The vehicle was dry until I filled up the radiator so there is no extra pressure on the system and you can see where the water is leaking down but I can't see the source. You can see deposits from a stop leak I was assured would fix it. I'm just looking for input and advice before I tear into the top end and so I can get this back on the road/trail. thanks for your help.

 

[92exp4x4]

Could be a number of things. Manifold gasket, head gasket, or a core plug on the end of the head. Take the power steering pump bracket off. You will be able to see what it is. You don't have to open the system to do it.

 

[Wiseone]

I agree you will will need to unbolt a/c if equipped and ps pump bracket to better see.
I had a leak that was hard to find on that side that turned out to be a timing cover gasket leaking coolant.

 

[Vilkas]

So finally had the time to get back to work and sure enough there is clear evidence of the lower intake manifold leaking from the front driver's side water port. Also signs that it may of been leaking or close to failing at the rear. Not really looking forward to trying to get everything put back as there is a ridiculous amount of hoses, wires etc. Very happy to have found the problem and that it is a cheap fix. I'm having my sixteen year old son do all the work so it's taking a bit more time but has been enjoyable. Thanks for the help.

 

[natenkiki2004]

This was the first time I saw the pictures but, yea, that's 100% classic lower intake leak. Glad you're getting it sorted out. It's not a tough job, just a bit tedious in cleaning surfaces and doing prep work. I don't even think there's any specialized tools needed. E7 torx is required to remove the fuel rail from the lower intake but you don't have to do that to remove the lower intake.

 

[Vilkas]

Yep sure enough it was the water jacket leaking from driver front side of the lower intake. Finally had time to get it together now I'm just trying to track down a vacuum leak. It seems to be from behind the manifold. BTW thank you Nate for your videos on the Explorer. Also has anyone found silicone to use for vacuum hoses at local retailers? I would like to try it but dont want to wait a week as we will be around -20F next weekend.