Coolant Leak 1999 5.7

[Modoyadney]

Hello guys,

For some time I've noticed a very slight loss of coolant. Today I decided to take a closer look and I noticed a drop of coolant on the starter motor.
I took a closer look with a mirror and I suspect a little leak between the cylinder head and the block right above the starter motor.

Could there be any another source of coolant in this area?
Or is it probably the head gasket?

I was worried that there might be a bigger problem with the head gasket. But as far as I can tell there was no visible oil in the coolant nor any sludge on the oil cap and the oil on the dipstick looks fine.

 

[Hoesgottaeat2]

Known areas are head gasket and intake manifold gasket. If it's not too significant and you don't want to do a tear down just yet, I personally have used stop leak. Stay away from the pelletized type as that has a tendency of clogging the overflow tank orifice. I've had very good luck with this product in (2) of my 5.7 Vortecs for small head gasket leaks and also in another GM 6-cylinder sedan we have that had an intake manifold gasket leak. Virtually all are drip free to this day as a result. Just follow the directions.

 

[strutaeng]

I vote for intake manifold gasket as well.

I think you can rent a pressure test kit from the local parts store to confirm.

 

[OR VietVet]

On the passenger side of the engine and on top of the engine, there is a PITA heater hose connection at the passenger side front top area. Known for leaking coolant and then can puddle enough to run back along top area and drain off at the back, when driving and the coolant moves. Or the intake. You can rent a cooling system pressure tester and do a proper basics test and see what happens. Do it with a cold engine.

 

[Hoesgottaeat2]

On the passenger side of the engine and on top of the engine, there is a PITA heater hose connection at the passenger side front top area. Known for leaking coolant and then can puddle enough to run back along top area and drain off at the back, when driving and the coolant moves. Or the intake. You can rent a cooling system pressure tester and do a proper basics test and see what happens. Do it with a cold engine.

Right on @OR VietVet. That plastic tee fitting in that area is a known culprit for cracking.

 

[east302]

Whenever that heater hose fitting leaked on mine, it ran down the valve cover valley and dripped from the starter bolts.

 

[Hoesgottaeat2]

Whenever that heater hose fitting leaked on mine, it ran down the valve cover valley and dripped from the starter bolts.

View attachment 407458

Never had that one fail on me. But I’ll be watching mine now that you mention it.

 

[OR VietVet]

I have dealt with fixing that over the years, approximately a dozen times. Half the time the pot metal snorkle, where the hose snaps in, would not unthread and would break off. Some guys just said, needs a new intake. I had to do a new intake one time but the other times I was able to get a sharp small chisel and a hammer and coming at it from the side, was able to break off chunks and dig them out till I had a whole side out and then the rest would vibrate loose and collapse on itself. We always had one guy in the shop that had a thread chaser/tap to use and clean the threads and then gobs of anti-seize on the threads for reinstall of a new snorkle/fitting. PITFA! Worth every dollar I charged for the labor time to do that.

 

[east302]

Never had that one fail on me. But I’ll be watching mine now that you mention it.

Haven’t had one break in the intake during removal, but I’m sure that’d be worth a few dozen cuss words. Mine usually just end up leaking from inside the fitting where the end of the hose meets and overflowing a bit of coolant.

 

[the 18th letter]

I have dealt with fixing that over the years, approximately a dozen times. Half the time the pot metal snorkle, where the hose snaps in, would not unthread and would break off. Some guys just said, needs a new intake. I had to do a new intake one time but the other times I was able to get a sharp small chisel and a hammer and coming at it from the side, was able to break off chunks and dig them out till I had a whole side out and then the rest would vibrate loose and collapse on itself. We always had one guy in the shop that had a thread chaser/tap to use and clean the threads and then gobs of anti-seize on the threads for reinstall of a new snorkle/fitting. PITFA! Worth every dollar I charged for the labor time to do that.

https://www.amazon.com/Lisle-62200-...ocphy=9060351&hvtargid=pla-568792428374&psc=1 saved me a couple times.