So I sometimes find coolant underneath the car, coming from BACK of the motor (this is not a thirdgen btw, but standard SBC 350). There is very little room behind the motor to look/feel for anything.

I suspected intake so pulled it, replaced seals and I now don't think that was it although the engine hasn't been restarted since yet.

- I attached pic of valve covers, it sure seems like I have internal coolant leak somewhere too right?

- but dipstick has CLEAR oil only. No milk residue at all.

- also there is very little milky residue in the heads, could it just be humidity causing that milky junk on valve covers? engine hasn't ran in 2 months.

- Short of cracked block where else could coolant be coming from? rear freeze plugs? Any way to test for this and nail it down before removing the engine?

It's just odd that I'd have internal AND external coolant leak like that, yet the engine ran awesome (probably will again), no smoking , most of the time it doesn't even leak coolant but sometimes when it gets hot like I said the rear of the engine will produce solid puddle.

 

Intake gasket

 

to explain the internal leak? I took a pic of the old intake gaskets and they looked ok. Since they have already been changed I'll hope you're right. Not sure if I can blame the intake gaskets for the external leak though

 

Borrow or rent a cooling system pressure tester:

http://www.harborfreight.com/radiato...kit-69258.html

Make sure the cooling system is full. Hook it up and pump it up. It'll expose the leak pretty quick.

 

Yup...

The water passages at the front and rear of each one (4 places) face the outside world on the outside, and the crankcase (lifter valley) on the bottom.

The rear one on one side or the other, leaks, maybe even both.

"Already been changed" pretty much seals the deal. Didn't get put back together right in some way.