Leaking coolant from reservoir after driving more than 15 mins

[jman11788]

So I've been leaking coolant on a hot day and driving for a bit. I replaced the tank and filled it back but still leaks. The truck won't overheat or anything but it seems to rev a little louder than normal under 25mph.. I know I need to replace the timing belt and water pump and probably thermostat soon. Any ideas why I'm leaking?

 

[reelamin]

Replace your rad cap.....if it continues...put a pressure gauge on it. Don't panic it's probably not a head gasket....LOL...just had to say that.

 

[jman11788]

Replace your rad cap.....if it continues...put a pressure gauge on it. Don't panic it's probably not a head gasket....LOL...just had to say that.

I'm so worried it could be a head gasket lol!

 

[rallypoint_1]

The coolant is being pushed into the resivior?? Hmm...does it get sucked back into the radiator when cool? If no, then it could be a blown headgasket. Another thing...are there bubbles in the resivior when the truck is warm?

 

[alumarine]

Is it "leaking" out the overflow hose on the reservoir or is the level going down in the reservoir?

 

[thegipper]

OP, you need to give us more details for us to be able to help you.

Where exactly is it "leaking" from? That would be a good start.

 

[jman11788]

OP, you need to give us more details for us to be able to help you.

Where exactly is it "leaking" from? That would be a good start.

Pretty sure I said its leaking from the tank. It'll spew out of the cap. It'll drain out almost all of my coolant and It will be close to empty when it's done leaking.

 

[phattyduck]

Does the temp gauge ever move above the center mark? A scangauge, ultra gauge or similar OBD reader can also tell you actual water temps at the outlet of the motor - it might help the diagnosis.

I'd start with the easy one, like reelamin said - radiator cap, OEM only! If the system can't hold pressure, it will boil near the cylinders and push coolant out the radiator cap, fill the overflow and come out the vent on the overflow.

You can also test for exhaust gasses in the coolant, but that is less likely.

If the other stuff is due (radiator, hoses, thermostat with jiggle valve at 6 o'clock, water pump, etc.) then do that next.

-Charlie

 

[jman11788]

Going to the dealer to get a new rad cap. We"ll see how it goes

 

[thegipper]

You just said you replaced the tank but it still leaks, I didn't see any mention of the cap. No biggie, just wanted to make sure we knew exactly what was going on so we could better help you.

I would do what Phattyduck said, that is a good start.

 

[Mark_BC]

I had the overflow tank boil over once when I overheated going up a hill. All due to a bad radiator cap I believe. Pisses me off that something so small can cause overheating and possibly longer term head hasket problems. Same with those stupid coolant lines underneath going back to the rear heater which rust out on earlier year models (later years are alumjnum). When they finally do leak you lose your coolant and overheat the engine. I think I have a compromised head gasket all because of this.

 

[thegipper]

I had the overflow tank boil over once when I overheated going up a hill. All due to a bad radiator cap I believe. Pisses me off that something so small can cause overheating and possibly longer term head hasket problems. Same with those stupid coolant lines underneath going back to the rear heater which rust out on earlier year models (later years are alumjnum). When they finally do leak you lose your coolant and overheat the engine. I think I have a compromised head gasket all because of this.

^This is exactly why I bought an Ultragauge to monitor engine temperatures. I have an alarm set on it for 215degrees. If I ever hear that alarm go off, I'll immediately pull over and shut it down. The gauge on the dash is completely worthless until it's too late.

Best 80 bucks I've spent in awhile...

 

[jman11788]

Well just got back from the dealer to pick up my cap. Opened the hood as soon as I parked it and the overflow tank is boiling.. this does not look good.

 

[mtbtim]

Well just got back from the dealer to pick up my cap. Opened the hood as soon as I parked it and the overflow tank is boiling.. this does not look good.

Compare the old cap with the new one. The OEM caps are known to fall apart and the small center plastic cap and spring end up somewhere in the top of the radiator. If your old one was missing parts, it wasn't holding pressure like it should.

 

[jman11788]

As a matter of fact I took off the old one to inspect it and saw a piece stuck in the top of the radiator. Here's a couple pics



Sent from my iPhone using Tapatalk

 

[Mark_BC]

If that's the case then you may not have caused overheating damage. If the cap can't maintain pressure then this will lower the boiling point of the coolant and make it boil but the temperature shouldn't be all that different than if it was pressurised and still liquid. Unless all that boiling coolant prevented proper coolant flow through the engine block.

 

[jman11788]

I've been driving it around for about 2 hours in stop a go traffic and the problem seems to be resolved! Pretty sure that If i took this to a mechanic they would have said I had a blown head gasket. That's why I love this forum! Thanks guys. I'll let you guys know if the problem comes back. All is well so far

 

[Unner]

Glad to know it was an easy fix. Radiator cap really should be preventative maintenance. I keep a new spare Toyota one in the truck too. But I'm a little anal about maintenance and running correctly I suppose...