Blown headgasket??? Coolant flow problem

[BDaddyK]

i have a 94 3.0 w/approx. 128k miles. As of late after the truck warms up and reached operating temp. under load the coolant will collect in the overflow tank and begin to seep out of it. The coolant circulates normally through the system until it reaches temp and under load, then it just collects in the overflow tank and leaks out of the overflow tank hose gasket. I thought it might be the radiator cap, changed it and no difference. I also changed the t-stat too, no difference. I thought water pump but the coolant circulates through the system until it gets to temp and you drive it and it doesnt overheat. I've also flushed the coolant twice now too. The only other thing I can think of is headgasket? Any help would be appreciated.

 

[shane96ranger]

i have a 94 3.0 w/approx. 128k miles. As of late after the truck warms up and reached operating temp. under load the coolant will collect in the overflow tank and begin to seep out of it. The coolant circulates normally through the system until it reaches temp and under load, then it just collects in the overflow tank and leaks out of the overflow tank hose gasket. I thought it might be the radiator cap, changed it and no difference. I also changed the t-stat too, no difference. I thought water pump but the coolant circulates through the system until it gets to temp and you drive it and it doesnt overheat. I've also flushed the coolant twice now too. The only other thing I can think of is headgasket? Any help would be appreciated.

What condition is your radiator cap in?

 

[TimR]

fan?

 

[Big Jim M]

Do ya

i have a 94 3.0 w/approx. 128k miles. As of late after the truck warms up and reached operating temp. under load the coolant will collect in the overflow tank and begin to seep out of it. The coolant circulates normally through the system until it reaches temp and under load, then it just collects in the overflow tank and leaks out of the overflow tank hose gasket. I thought it might be the radiator cap, changed it and no difference. I also changed the t-stat too, no difference. I thought water pump but the coolant circulates through the system until it gets to temp and you drive it and it doesnt overheat. I've also flushed the coolant twice now too. The only other thing I can think of is headgasket? Any help would be appreciated.

Do ya know to turn the heater to hot and run the engine while filling until the operating temp is reached? Sometimes it is really hard to get all the coolant into these engines.
Most (if not all other) modern engines have DOORS that open and close to allow the heat to pass in the heater. The hot coolant flows thru the heater at all times. OUR rides have the old fashioned system that OPENS the flow of coolant into the heater when the heat is turned up. So when fillling the system with new coolant the flow MUST push all the air out of the heater!!
Your problem sounds to me like a bunch of air in the system.
Big JIm

 

[shane96ranger]

What I meant to say above was; Is it the correct rating on the radiator cap?

I got one once that was rated at a lower poundage than stock and it kept spilling over on me as yours is.

(sorry about the above post, I was interrupted while typing and I'm not a good multi-tasker)

 

[Rearanger]

If no air in system as BigJim suggests, then given what you've tried/inspected so far, possible fan clutch and/or just an old radiator that needs to be replaced. You might try using the heater full on to see if that makes a difference to coolant overflow.

 

[locovaca]

How full is your overflow tank when it's cold? Are you sure it's actually "overflowing?" I had to put RTV on my elbow as it was not sealing against the tank and would leak when the coolant sloshed around in the tank.

You might also rent a cooling system pressure tester. If you had a blown head gasket it should show with that.

 

[BDaddyK]

Yes, did turn the heat on full blast when I filled the coolant. I don't think ( you know how that goes though) there is any air in the system, is there a reliable way to purge air from the system if so?

The radiator cap I bought is OEM replacement 16 lb cap (old cap i replaceled looked pretty beat) or at least that what is listed on the cap. I don't have the truck with me here at work at the moment.

The overflow tank looks good. It's not actually "overflowing" from the tank. It's leaking out from around the rubber gasket that the plastic pickup elbow sits in at the top of the tank. The coolant level in the tank never gets high enough to actually breach the top of the tank.

Does Autozone, or the like, rent cooling system pressure testers?

 

[locovaca]

Yes, did turn the heat on full blast when I filled the coolant. I don't think ( you know how that goes though) there is any air in the system, is there a reliable way to purge air from the system if so?

The radiator cap I bought is OEM replacement 16 lb cap (old cap i replaceled looked pretty beat) or at least that what is listed on the cap. I don't have the truck with me here at work at the moment.

The overflow tank looks good. It's not actually "overflowing" from the tank. It's leaking out from around the rubber gasket that the plastic pickup elbow sits in at the top of the tank. The coolant level in the tank never gets high enough to actually breach the top of the tank.

Does Autozone, or the like, rent cooling system pressure testers?

Yes, AZ rents the pressure tester. I would still test but I don't think you have an issue with a head gasket.

Take a look at this thread: http://www.therangerstation.com/forums/showthread.php?t=99703

In addition to that, like I said, I would rtv the entire thing down. After 15+ years the plastic wears out and isn't as tight fitting and the coolant gets out when it sloshes around in the tank. At a minimum it eliminates it as a point of failure.

 

[BDaddyK]

Yes, AZ rents the pressure tester. I would still test but I don't think you have an issue with a head gasket.

Take a look at this thread: http://www.therangerstation.com/forums/showthread.php?t=99703

In addition to that, like I said, I would rtv the entire thing down. After 15+ years the plastic wears out and isn't as tight fitting and the coolant gets out when it sloshes around in the tank. At a minimum it eliminates it as a point of failure.

Thanks for the link. That is how mine is leaking out. It leaks pretty good too, only after the engine has been under load though. It can idle all day long and no leak/problem.

I did take the elbow out, no blockage, nor in the line that runs from the rad. to the overflow tank. Should I RTV the actual rubber gasket itself or pull it out and the sides of it? I'll also try cutting the hose back and re-clamping it like suggested in the linked thread. I'll also do the pressure test too, just to see.

 

[BDaddyK]

Finally got the pressure tester. Did the test stayed at a rock solid 16ish psi. I pumped the gauge until the needle was on the 16 side of the 15-16 psi area. It said to leave it on for 2 min, it was prolly on for a good 30-40 min or so as I checked for leaks, it held firm on the 16 the whole time.

I did notice one small leak right at the bottom (trans cooler line?) fitting. The bottom fitting (closest to the ground) on the driver side of the radiator (second fitting down from the filler neck) the line that runs from the small transmission cooling radiator. There is a small leak coming from the area of that fitting, I have never noticed it before. Would be enough to cause my problem?

 

[ussraven61]

Ok I had this same exact problem and after replacing almost everything under the hood (as far as the coolant system goes) I broke it down and took the head gaskets off to find out the one on the left bank had a nice pin size hole in it. Atleast thats how my mileage varied lol. So now I discovered my truck leaking oil from the heads and I can get them to stop. Any advice on that one?

 

[BDaddyK]

Ok I had this same exact problem and after replacing almost everything under the hood (as far as the coolant system goes) I broke it down and took the head gaskets off to find out the one on the left bank had a nice pin size hole in it. Atleast thats how my mileage varied lol. So now I discovered my truck leaking oil from the heads and I can get them to stop. Any advice on that one?

Your truck hold pressure with the pin sized hole in the HG? That's what's getting me, I'd think that even with a pin sized hole the coolant system would leak, even if it was really slowly. I left the pressure tester on for a good 3-4 hrs while I ran some errands the other day and it never lost pressure. There is still a little bubbling coming out of the hose in the overflow tank though.

 

[TimR]

Your truck hold pressure with the pin sized hole in the HG? That's what's getting me, I'd think that even with a pin sized hole the coolant system would leak, even if it was really slowly. I left the pressure tester on for a good 3-4 hrs while I ran some errands the other day and it never lost pressure. There is still a little bubbling coming out of the hose in the overflow tank though.

Your pressure test, was it cold, or hot? Some leaks won't show till it warms up. The bubbles, though could just be air trapped in system, too.

 

[BDaddyK]

Your pressure test, was it cold, or hot? Some leaks won't show till it warms up. The bubbles, though could just be air trapped in system, too.

That was cold.

I also tested it hot too, to the same result, no pressure loss. I let it get up to temp, and the pressure came up to and stayed at a solid 16 psi. Well the needle stays at a just a little past the 1 on the 16 side of the area on the gauge marked 15-16 psi.

Is there a way to totally purge the system of air?