Cooling system woes

[Ranger Mark]

96 3.0 automatic rwd

Pressure building in cooling system. Unable to squeeze upper hose. Does not overheat. Does not push coolant into overflow tank. It does draw it back in when cooling. Does loose water when capped. No evidence of where it is going. (No white smoke, exterior leaks, etc.) Uncapped, (with funnel in place) coolant keeps expanding. Only time I have air bubbles is about 10 - 20 seconds after revving engine and squeezing upper hose.

New caps (tried a couple different ones). Water pump is good. Tstat verified ok. Block test shows no exhaust gasses present. Glove test was negative. Lower hose cool to touch but firm with cap off.

It's a simple system and I know I'm over thinking it. Could a blockage of the coolant passage's be the cause? I keep going back to head gasket, but maybe cracked head or block? As far as the caps go, if there is air in the system, 15 psi of air vs. 15 psi of coolant is not the same. Air is compressible but water is not. (This is where I'm over thinking it somehow)

 

[Ranger Mark]

Maybe I found where the coolant is going. It's 80 degrees here. Seems like excessive water to me.

 

[Craig0320]

How long has that been running in that picture. Past 10 minutes all condensation in the muffler should be burnt out. If it is still coming out like that longer than that you need to pull plugs and start looking fat color for signs of water. If you can look at your pistons. The cylinders getting water in them should be a lot cleaner because water cleans the crap out of them. Seen it many times on head gasket failure.

 

[PetroleumJunkie412]

Not all that knowledgeable on 3.0, but pressure from combustion should be easy to spot. Check the normal places - any gasket that has coolant pass through it.

Other than that, if you're picking up ambient air on a pressure or flow increase in the coolant system, I. E. Revving, check the coolants path in overlooked places like your heater core and water pump.

At one point my 1988 blew a heater core. Thought I had a coolant issue with the heads or gaskets. Just a pinhole in the core.

 

[RonD]

Yes, I think you are "over thinking it"
If you are not over heating, yet, then system is "OK"
Cooling system should run with 14psi pressure inside, rad cap rating

If you are losing coolant but no sign of a leak then it is leaking near a warm spot so is evaporating before it can drip
Best way to find that type of leak is to rent a cooling system pressure tester
Its a radiator cap with a hand pump and pressure gauge
You pump up COLD and full cooling system to say 20psi, and watch for pressure to drop, it means there IS a leak, then watch for the dripping coolant, since it can't evaporate it will drip to the ground

After thermostat opens, takes about 4 to 8 minutes depending on outside temp, have some one REV the engine, squeeze the upper hose to see if it gets "harder" at higher RPMs
Then squeeze lower hose and see if it gets "softer" at higher RPMs
When thermostat is open, the water pump pushes out hot coolant thru the upper hose, and Sucks coolant back in thru the lower hose
If radiator flow has some blockage then lower hose will get softer as water pump flow gets higher, i.e. higher RPMs

If temp seems to go up a bit when driving slow or stopped , then fan clutch can be the issue


Tail pipe will always drip water(H2O), when you burn gasoline(a hydrocarbon,H), in the presence of air(oxygen, O) you get a by-product of H2O(water)
This is why exhaust systems RUST from the inside out
Just chemistry, and if its humid out then even more water from the air engine is using
All gasoline has some water in it as well, so more water, "bad gas" means too much water in it

 

[Ranger Mark]

Thanks for the replies. After pulling the #1 and #4 plugs I found the #1 with rust from cooling system. Head gaskets is the winner. May be hard to tell in the picture but both plugs are dry. One is just coated with rust.

 

[RonD]

Head gasket?

A cylinder has cranking compression of 150psi, firing pressure of 1,000+psi, rad cap is rated at 14psi, so you will KNOW if head gasket blows or head cracks, pretty darn fast.

Not rust

 

[Dirtman]

Plugs in a cylinder with coolant entering it would be immaculate white from being steam cleaned, not rusty.

 

[Ranger Mark]

I'll let you all know what I find out when I rip it apart.

 

[cbxer55]

Yeah, my sister once had a S-10. Had a head gasket leak. The fluid in the overflow tank would boil like crazy. I wonder how that could be unless the overflow tank is more like my Lightnings. The Ranger just has the little hose to and from the tank. The Lightning also has the small hose, but it also has a large hose on the bottom that "T's" into the lower radiator hose. We call that lower hose the Octopus hose. Hard to get to. I could see a cylinder head leak boiling the water in the overflow tank with this arrangement, not so much with just that little hose.

 

[RonD]

Water/coolant in the tank is hot but not boiling

The head gasket leak(or cracked head) allows "exhaust" to be pushed into the cooling system when that cylinder fires, and then it sucks in coolant in on the intake stroke, steam cleaning spark plug tip.

The air/exhaust that was pushed into cooling system ends up at the top of the radiator after thermostat opens and that air is what is being sent over to the overflow tank, and why the tank bubbles.

Because this air coming into the head displaces the coolant in the head the engine will start to overheat, the pressure from the firing cylinder(1,000psi) increases pressure in the cooling system above the 14psi rad cap rating, forcing coolant in the radiator out to the overflow tank, and when the air/exhaust makes it to the top of the radiator then it is forced out and you see the bubbles in the tank.


A chemical "block test" is testing for "exhaust" chemicals in the coolant, which would mean blown head gasket or cracked head
Glove test is simpler and better because you can ID which cylinder is leaking if you want


Bubbles in the overflow tank is not always head gasket issue, if your coolant is low then air will be at top of the radiator, if engine gets hot enough pressure will exceed 14psi and the air at the top of radiator is sent over to tank, and bubbles up
When you shut off any engine, coolant circulation stops because water pump is no longer turning, this causes the coolant in the heads to get hotter very fast, which can increase the pressure above 14psi cap rating, and if there is air at the top of radiator........then bubbling in the tank

 

[PetroleumJunkie412]

Water/coolant in the tank is hot but not boiling

The head gasket leak(or cracked head) allows "exhaust" to be pushed into the cooling system when that cylinder fires, and then it sucks in coolant in on the intake stroke, steam cleaning spark plug tip.

The air/exhaust that was pushed into cooling system ends up at the top of the radiator after thermostat opens and that air is what is being sent over to the overflow tank, and why the tank bubbles.

Because this air coming into the head displaces the coolant in the head the engine will start to overheat, the pressure from the firing cylinder(1,000psi) increases pressure in the cooling system above the 14psi rad cap rating, forcing coolant in the radiator out to the overflow tank, and when the air/exhaust makes it to the top of the radiator then it is forced out and you see the bubbles in the tank.


A chemical "block test" is testing for "exhaust" chemicals in the coolant, which would mean blown head gasket or cracked head
Glove test is simpler and better because you can ID which cylinder is leaking if you want

Why haven't you gotten a Google voice account and started a pay-by-the-minute dial-a-tech line yet? ?

 

[Ranger Mark]

Maybe I'm crazy, but this is the same crap on my #1 plug. Stop leak?

 

[Dirtman]

I reliquish my comments to Ron. Cause I aint got a clue what that crap is.

 

[Ranger Mark]

The area on the block under the leak. It was on the backside of the gasket.
Bottom pic shows the hole in the gasket.

He