My 1994 Ranger Splash 4.0 is leaking water/coolant someware. Before I leave the house I always fill radiator and over fill /wwwasher reservior container to prescribed levels. I go into town and back-about 20 miles and water is gurgling back to the reservoir and leaking out of the cap on top of the reservoir. The cap does not seem to come out.

Ok my mechanic say that perhaps there is a leak behing the timing chain cover? I never see and water on the drive way? The engine seems to run hot but the inside temp gauge is running normal. Whats going on? Thanks

 

Do you notice white smoke coming out the tail pipe on start up and for a few minutes after start up?

If overflow tank is filling up and bubbles are coming up then you most likely have the start of a blown head gasket, maybe a cracked head

I would do a FREE glove test first, just to take head gasket issue off the table

Glove test outlined here: https://www.ranger-forums.com/4-0l-o...oblems-157777/

Its simple and FREE

If you want to spend money on something just because, then get a new radiator cap, that's about the only thing "else" that could cause your symptom

 

Thank you for replying. There is no white smoke or any smoke coming out of tailpipe at startup and after running for awhile. Radiator cap was replaced last year and inside temp gauge never goes past 1/2 way. What happens is that water blows out of the cap on the water/reservoir. as it gurgles back to the overflow tank. I will do glove test as suggested but perhaps use JB weld to glue that cap down?

 

NO, do NOT glue the cap down, lol, I am sure you were joking

Cooling system is pretty easy to understand
If you heat any fluid, like water or coolant, it will EXPAND in volume, so if you have 1 quart of coolant at 70degF temp, and heat it to 180degF temp it will now be 1.25 Quarts

Boil point of coolant is 230degF at outside pressure(water 212degF), but if you add 14psi pressure to the coolant boiling point is now 260degF

So coolant expands when heated and boiling point is raised by pressure.......................hey great idea, let use the expansion to create PRESSURE
Thats what radiator cap is for

As the coolant is heated up by the engine it starts to expand, so pressure builds up in the engine and radiator, the radiator cap holds in the pressure until it gets to 15psi, then it opens and sends HOT coolant over to the over flow tank, as it should EVERY TIME you drive more than 20 minutes or so
So 14psi cap opens at 15psi to let some coolant out then closes to hold system at 14psi.

Here's the neat thing, the radiator cap has TWO valves, the big one with big spring, and the small one in the center with small spring
So you have shut off the warmed up engine with 14psi pressure in it
Coolant starts to cool off and SHRINKS back to its 70degF volume, so pressure starts to drop, 12psi, 10psi, 8psi.......ect until 0psi, now if ANY coolant was sent over to the over flow tank, the pressure will drop to -1psi, negative pressure
This SUCKS open the smaller center valve, which then SUCKS coolant back in from the over flow tank, this is why the over flow tanks hose is at the BOTTOM of the tank, so it sucks in coolant NOT air.

So if your system is working as it should.......after engine is cooled off radiator should be FULL TO THE TOP no air at all, its self purging of air, those are the bubbles you see in the overflow tank
Any air in the system will end up at the top of the radiator, so when pressure gets to 15psi the AIR GOES OUT FIRST, and bubbles up in the tank and is gone, when engine cools down COOLANT is sucked back in to replace the air


If Glove doesn't bounce then the easiest way to find a cooling system leak is to use a cooling system Pressure tester, you can rent them for under $20 usually.

It's a radiator cap with a gauge and a hand pump
You install the cap and pump up the system to 20 psi then watch for pressure to drop and for the leak if it does drop
With Cold engine the coolant won't evaporate at the leak point and will drip to the ground

 

I was joking. Excellent description that I somewhat uderstand- but so much fluid gets out that the reserve is empty after 20 minutes of driving

 

How would the reservoir get empty?

Coolant can come out the top, if there is a problem with engine cooling system, but reservoir would remain full because there is no lower drain for fluid to drain out

 

Check your oil. Does it look good or like milk chocolate?

 

Here is what I know: the radiator cap is ayear old with some rust, after twenty minutes of driving hot water comes out of cap on top of reservoir, I am pointing to it. There is no white smoke or any smoke at startup or when driving. Thanks

 

Have you done the glove test RonD suggested? It's kind of hard to give someone helpful info without feedback.

 

Thats a pretty dirty cooling system, loads of rust which could be from not changing coolant every 2 years or a head gasket issue

Because of the look of the rad cap I would also guess thermostat, water pump and radiator issues

The 20 min delay would point AWAY from head gasket issue, and to a flow issue, which is thermostat, water pump or radiator

You can drain the radiator, and pull it out, just 2 bolts, should be very light, flip it over, if water/coolant comes out it is blocked up,

You can remove lower hose from water pump and use a bore scope type camera to look at the water pump impellers, the blades can be eaten away by the rust you see on rad cap so its not "pumping" like it should so engine heats up and blows out water/coolant

Thermostat is cheap and not hard to replace

 

Hello alleng8304,
Have your mechanic do an exhaust gas check at your radiator fill cap.
My cap and radiator looked just like that.
In the past year I replaced the heater core, radiator, water pump, hoses, radiator (again) and heater core hoses.
After all that It started blowing off hoses. Replaced the clamps and the lower hose blew again.
My a mechanic did an exhaust gas test where he runs the 'air' from the radiator fill through a liquid that turns color in the presence of exhaust gases and it did.
That is a blown head gasket where the exhaust gasses are backing through the coolant system.
After all the work I have done (clutch, fuel pump, 2 sets of rims (factory and after market with snow tires) and a whole bunch of other stuff I just don't feel like doing any more work on it.
198200 miles but I won't get over the top.
It is a shame because there is no rust at all and it started every day but after 10 years I just don't have it in me to work on it, the head gasket is just too much for me.

Oh well, I hope it helps you