Massive coolant leak into the exhaust

'96 Explorer 4.0, 4 door, 4wd, automatic. 192k miles.

It's been using coolant for some time, coolant turns heavily rusty despite several flushes, and I can always smell it a little bit. Topped it up two days ago, drove 15-20 miles, let it sit until this morning, and the radiator is empty as far as I can see. Fill it up, start engine, and it's blowing water/coolant out the tailpipe. So much in there that it's dripping off a dozen spots along the exhaust and I can hear it bubbling in the muffler, sounds like an boat engine idling at the lake.

Drove it over a couple hundred miles of mountain pass and desert last week, and now I'm thinking it was probably low/out of coolant even then.

My thinking here: absolute best case scenario is a blown head gasket, more likely is a cracked block or head. It's leaking badly enough to dump over a gallon of coolant into the cylinder/exhaust in minutes, or less.

Input from those who are more familiar with these engines?

Video from below: https://www.youtube.com/watch?v=XXMwZ--OsGc

Ouch.

I'm not too familiar with that year but unless there's a water jacket that runs through the intake that has a failed gasket, I'd say you're spot on with your diagnosis.

Any water in the oil?

BobRob said:

Ouch.

I'm not too familiar with that year but unless there's a water jacket that runs through the intake that has a failed gasket, I'd say you're spot on with your diagnosis.

Any water in the oil?

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Pulled the top end apart today, and found a great deal of bad news.

The left front cylinder has significant corrosion in the intake runner, so it looks like it's been leaking water in there for quite a while.



And judging by the underside of the manifold, the oil/water mixing has been extensive. Whole top of the engine is filled with this sludge, and the coolant passages are almost completely blocked with rust and crud.



So now I'm debating between scrapping the rig, swapping in another engine (there are explorers all over CL here for $500-1000) and building up a nice little 5.0 with a Holley carb and making an Explorer GT.

cycle61 said:

<<snip>>

So now I'm debating between scrapping the rig, swapping in another engine (there are explorers all over CL here for $500-1000) and building up a nice little 5.0 with a Holley carb and making an Explorer GT.

Click to expand...

That sounds like fun...lol