Slowly disappearing coolant

[tracymckibben]

I need help solving a mystery. 2008 Eddie Bauer V6, slowly losing coolant. How slowly?

- six months ago, I noticed the overflow was bone dry. I filled it to the "Full Hot" mark. Radiator was full, no overheating, just a dry overflow.
- I monitored for a couple of weeks, no apparent problems, stopped paying attention.
- Three weeks ago, I noticed the overflow was again dry. Again, no overheating, no signs of trouble.
- With the engine hot, I topped off the overflow, filling it to the "Full Hot" mark.
- Today, the overflow level is about an inch below the "Full Hot" mark.

There is no coolant in the oil. No oil in the coolant. No puddles on the ground. Nothing coming out the exhaust, no drips or white smoke. There is an antifreeze smell, strongest in the vicinity of the radiator cap, but no visible leak. The ONLY possible sign of leakage that I can find is a white crusty residue around the overflow hose where it attaches to the radiator neck.

Any clues? Again, both times I've found the overflow dry, the radiator seemed to be at the proper level.

 

[kam327]

Slow head gasket leak.

My '06 V8 developed a head gasket seepage early this year. I noticed my resevoir level going down slowly just like you but no puddles on the ground. Finally one day I was changing my oil an noticed a path of burned coolant down the side of the block. Went up to where the head meets the block and it was a little wet. What was happening was the coolant was leaking out slow enough to burn off on the block before dripping on the ground.

I'd get under the engine and look all around the heads and block for signs of a coolant leak.

 

[edwx]

Agree with Kam. It's probably leaking and evaporating. I had the same problem, not a head gasket though, just a small radiator leak. It was a slow enough leak that I just lived with it. Switching to a 16psi cap helped also.

 

[jrford]

For a head gasket leak there is something called a leak down test. They pressurize the system and attach a pressure gauge and see if it drops and how long it takes to drop.

On one of my trucks, it was the coolant overflow bottle that was leaking. Overflow was empty but Rad was always full.

 

[nleipziger]

Tracey, check for coolant where the intake manifold would be. I just replaced the lower thermostat housing causing the coolant to puddle on the engine and evaporate.

 

[alox]

I second nleipziger.

I replaced the thermostat housing because of the same issue

 

[swshawaii]

For a head gasket leak there is something called a leak down test. They pressurize the system and attach a pressure gauge and see if it drops and how long it takes to drop.

On one of my trucks, it was the coolant overflow bottle that was leaking. Overflow was empty but Rad was always full.

Ditto. A coolant system pressure test kit is the fail safe method of finding coolant leaks.
Most auto part chain stores rent them with a 100% refundable deposit. Call around. GL

 

[tracymckibben]

Thanks all. Looks like I'll be spending some time on the garage floor tomorrow. I've already looked around the thermostat housing after finding some others on here talking about a leak there. No signs of any coolant, liquid or dried. I'll get under there tomorrow and check the sides of the engine block.

 

[cmk0808]

I just put a new radiator in for a friends 07 XLT V6. Check the back side of the radiator. You need to pull off the top cover by the grille to see the leak. His was all white over the backside of the radiator. Also the elbow at the bottom of the radiator also leaks. Check that too.


Willing to bet you need a new radiator.

 

[briwayjones]

Could be a slow head gasket leak. I had a similar problem and it was the lower intake gasket. On my parents Ranger it was leaking from somewhere low on the back of the engine, dripping on the exhaust and evaporating. If it's slow enough it won't visibly show up in the oil.

 

[tracymckibben]

Ding, ding, ding, we have a winner!

I just put a new radiator in for a friends 07 XLT V6. Check the back side of the radiator. You need to pull off the top cover by the grille to see the leak. His was all white over the backside of the radiator. Also the elbow at the bottom of the radiator also leaks. Check that too.


Willing to bet you need a new radiator.

Found it. Pulled the fan shroud off, and on the back side of the radiator, driver's side, about 8 inches up from the bottom, found a trail of greenish residue running all the way to the bottom of the radiator.

 

[willied]

I don't think your picture is big enough.

 

[granadojl]

I'm glad you found your coolant leak.

Another thing to keep in mind.... I just replaced my Oil Filter adapter gasket and the seal around the coolant passage was busted allowing coolant to leak out of the housing where the lower radiator hose connects to the housing. Just another thing to look out for for those of you who can't find the coolant leak.

 

[peter @exp]

Can you use stop for head gasket leak .my is doing it too 2004 exp sport trax

 

[granadojl]

That stuff is all a bandaid. I would only suggest using that crap if you're off-road and have absolutely no way out and crack the bottom of the radiator and you absolutely need that stuff to get to a shop.