Odd Coolant Issue

[Nicholas D]

Hello All. I've been steady working through my new-to-me '89 ranger and have had an odd issue that I can't seem to find a solution for. I go through quite a bit of coolant (about 3/4 - 1 gallon a month) but I can't figure out where it's going? It is leaking transmission fluid for sure, but it doesn't leak any coolant underneath that I can see anywhere. The tailpipe is nice and dry and it doesn't smoke or anything either. The radiator looks new and I've replaced the transmission coolant lines as they were leaking very slightly. All the other fluids remain fine, with the exception of occasionally adding ATF but certainly no fluid levels are increasing. It idles and runs great so for the time being I've just been watching the level and adding when needed. I'm finally getting through the other punch list items and so just wanted to pick the brilliant minds here for any possible suggestions? Thanks!

 

[Uncle Gump]

What engine?

Google glove test... see what happens.

 

[rusty ol ranger]

If its a 2.9....check your oil see if it looks like a milkshake

 

[dfratus]

Hello to all y'all. I was just now looking for answers to the coolant loss problem in my 03 3L ranger. Coolant reservoir was empty and the system took almost 3 gallons of water. I was quite surprised I didn't have a melt down. I could smell antifreeze when I parked it but no apparent leaks. Googled glove test and got nothing useful. It's always something . . . ?

 

[19Walt93]

I'd suggest both of you guys let your trucks sit overnight, then just crack the oil drain plug enough so that it starts to drip. If the coolant is leaking into the oil it will leak out of the drain plug first. Jack up your trucks the night before if you can't get at the drain plug with them on the ground. I'd also look closely at the freeze plugs, evaporator drain, and water pump to see if coolant is seeping. Look at the spark plugs, too, if one looks a lot cleaner than the others you may have a head gasket leak. 2.9's and 4.0 ohv's had some heads that would crack under the valve covers and allow coolant to seep into the oil. Water cools great if you don't need freeze protection but 50/50 antifreeze will raise the boiling point and provide a little anti rust protection.

 

[Uncle Gump]

Glove test...

A test that uses a rubber glove over the removed radiator cap of fill port to seal the cooling system. Cranking the fully warmed up engine and watching the glove. If the glove pulses or even fills with air... it would indicate a blown head gasket or cracked head.

If you added 3 gallons of water... this thing should have a visible leak or blowing steam out the tailpipe.

You can also pull the spark plugs and visually inspect. Water/coolant would typically "steam clean" the plug in the offending cylinder(s).

 

[dfratus]

I'm gonna try all these things. I checked the dip stick yesterday and oil looked clean but coolant is going somewhere it isn't supposed to. Thanks for the info.

 

[Nicholas D]

Thanks for all the tips, I'll start running through these suggestions. My oil level hasn't gone up, and the oil on the dipstick looks normal but I'll follow the above advice. Thanks!

 

[19Walt93]

We devised a quick head gasket test for the Mazda/ Courier trucks in the mid 70'sthat was quicker than pressure testing and checking spark plugs. Keep in mind that the hood opened from the rear. We'd remove the radiator cap and top up the coolant, get in and roll up the window, then we'd start the engine. A blown head gasket would send a coolant geyser into the air, onto the roof and windshield. We added "roll up the window" to our procedure after the first one. This won't help you but I thought it would be entertaining.

 

[RonD]

Rent a Cooling system pressure tester
Its a radiator cap with a gauge and a hand pump
Auto parts stores or tool rental places will rent them, $10-$15

Cold engine
Install the rad cap
Pump up the system to 20psi(normal pressure is 15psi)

Wait and watch
If pressure is dropping you do have a leak in the system, with a cold engine you WILL see it leaking to the ground
And with a cold engine you can reach around parts to find the leak point without getting burned, lol

With a warm engine leaks can evaporate before hitting the ground
And there is only pressure in the cooling system once its warmed up, so a small leak won't leak until engine is warmed up


There are also UV Dyes you can add to the coolant, and run the engine for a few days, then use a UV light to try and track down the leak

 

[Nicholas D]

Ha! I'd like to watch that but not clean up! I'm sure I'll somehow make an enormous mess, seems to be the only thing I can do with consistency.

I'll check with my local parts store and see if I can get a cooling system pressure tester for the weekend - thanks for the tip.

 

[dfratus]

Glove test...

A test that uses a rubber glove over the removed radiator cap of fill port to seal the cooling system. Cranking the fully warmed up engine and watching the glove. If the glove pulses or even fills with air... it would indicate a blown head gasket or cracked head.

If you added 3 gallons of water... this thing should have a visible leak or blowing steam out the tailpipe.

You can also pull the spark plugs and visually inspect. Water/coolant would typically "steam clean" the plug in the offending cylinder(s).

Ya make me wonder if any particular finger on the glove stiffens up first . . .

 

[RonD]

UV Dyes are not visible in normal light so no mess "to see"

UV(ultra-violet) light is needed to see it, people usually use a UV flashlight to find leak points
A "Black light" is a UV light

You can use UV Dye in cooling system, AC system, oil system, transmission, differentials, ect...............
But different colors are recommended, lol
Most Air Conditioner R134a refill cans come with a UV Dye mixed in now-a-days



Yes, the middle finger extends upward in a "you are number one" response
It is called the "Glove test" because most shops have boxes of latex gloves around so they have in house test equipment readily available
But you can use a balloon, or a plastic baggy, or even a condom to replace the glove

 

[gaz]

@Nicholas D ,
Please keep in mind that if you are troubleshooting a 2.9l cooling system, it's coolant system is only about 2 gallons total; if you are losing ¾ of a gallon in a month YOU HAVE A SERIOUS PROBLEM... don't drive this until resolved!!

If you do not have coolant leaking into you cab or on the ground...well, that is usually easy to guess but if you have a small leak anywhere it will eventually lead to an overheating situation.

If you are LUCKY, you have not damaged your engine yet and if so a complete new cooling system is not very expensive, however, I would replace the Radiator cap 1st:
$15 • radiator cap
$15 • thermostat
$8 • blue RTV
$100 • radiator
$ 80 • water pump
$ 60 • upper/lower coolant hoses with 2x clamps
$30 • heater coolant hoses (I fashion my own using hardware/automotive store hose with 2x clamps on each end)
$16 • double clamps all around (8)
$20 • 1 gallon 100% coolant

In summary, about $300-$350 for a complete new cooling system to insure that your investment has the time to pay you back.

NOTE: if you do need to or decide to fit preventative maintenance, change your water pump, that is a GREAT time to also lose the crank case driven fan/clutch for a 15" electric puller fan ..)

 

[rusty ol ranger]

If hes losing that much coolant and not looking like a steam engine going down the road or seeing obvious leaks i have a feeling the prognosis is not good