"low coolant"--> where's it going?

[Blackened302]

so here's the deal:

"low coolant" light comes on, so i fill up the tank. i also make sure the radiator is full (both when the car's off, and with the car running and the water circulating).

a few days later, "low coolant" is on again, and my reservoir tank is empy, though the radiator seems to still be full.

-no water in oil (thankfully!)

-no holes in reservoir tank (pulled it out, filled it up, shook it around, let it sit, and no leaks)


only thing i can think of is that the water is getting sucked into the radiator, then leaking out from somewhere else.. ?

where's my water going?

 

[94gsl5.0]

No obvious leaks... nothing on the garage floor?

Maybe time for a leakdown test, been there

 

[igotyofire]

i have same problem except mine is not a few days its more like every so often...maybe once in a month or once in 2 months.....i think it depends on how hard i drive the car.

 

[94-302-vert]

Factory radiator?

My radiator leaks only when it is really cold out. I would imagine that a hot radiator could drip slowly as well around one of the crimps. They don't leak fast enough to see anything under the car unless it drips on your face (literally)...

 

[Blackened302]

ahh, didn't consider my radiator being leaky.

funny thing is when i checked the reservoir for leaks, i checked the radiator, too.

although, i suppose if it were a slow leak, i wouldn't've been able to tell.

 

[Wi Stang]

I know that my factory radiator had a strange way of leaking.
It seemed like it would only leak while the car was warming up. Once it had been up to operating temp for a while, it wouldn't leak anymore.
the only time I would see any coolant on the garage floor is if I only took it for a short drive and then parked it in the garage.

It was leaking out of the radiator on the passenger side. I never could really track down for sure where the leak was.
I would need to add coolant every couple of weeks.

 

[94-302-vert]

This is how mine is, on the drivers side though. Doesn't leak enough that i have to top off the coolant very often so I don't worry. When it gets worse a new radiator is in order.

I know that my factory radiator had a strange way of leaking.
It seemed like it would only leak while the car was warming up. Once it had been up to operating temp for a while, it wouldn't leak anymore.
the only time I would see any coolant on the garage floor is if I only took it for a short drive and then parked it in the garage.

It was leaking out of the radiator on the passenger side. I never could really track down for sure where the leak was.
I would need to add coolant every couple of weeks.

 

[MLC Stang]

It was leaking out of the radiator on the passenger side. I never could really track down for sure where the leak was.
I would need to add coolant every couple of weeks.

EXACTLY !!! Same thing on my car... finally found it!

Our cars are notorious for developing a very slow leak on the passenger side of stock radiators, between the radiator core and the radiator end cap down low on that side.

It’s hard to see, and hard to diagnose, since it it’s a very slow leak and the leak mostly drips down onto the cross-member directly under the radiator, burns off, and never makes it to the garage floor.

Until I fixed that, my car had the same mysterious symptoms of a low coolant light every month or so, and some mild overheating when coming off of a long freeway run and getting back into slow city street traffic.

I can happen on the drivers side as well, but most common on the passenger side.

 

[Blackened302]

wow, i wasn't aware of the developing slow leak. i'll see if i can somehow patch that up 'til i manage to get a new radiator (hoping for a group buy on the Moshimoto).

thanks, gents.

 

[True 5.0]

I had a problem with leaking coolant into my #5 cylinder intake port for a few years. I had the same issue and could not diagnose it. I rebuilt my engine (long story there) and found the signs of the leak. I switched my intake and after my rebuild have not had any problems.

 

[Blackened302]

I had a problem with leaking coolant into my #5 cylinder intake port for a few years. I had the same issue and could not diagnose it. I rebuilt my engine (long story there) and found the signs of the leak. I switched my intake and after my rebuild have not had any problems.

what are the signs?

a little water in oil? markings on the head gasket?

 

[Kr33p]

I have the same problem with my ride it always needs water every other day, its goin under the knife soon.

 

[reddy351]

It's good to know that I'm not alone in the "tiny leak from the passenger side" in the radiator. Mine was about 3 weeks, between the dash light coming on. I paid $90 for a factory replacement radiator and the problem is gone. Yay! That was two years ago.

If you can't get to swapping the rad right away, this type of leak is what Barr's Leak is for. Most OEMs put it in the rad, just for safe measure. Saves them a bunch of money in warranty work. Just use a "as directed", though.

 

[True 5.0]

what are the signs?

a little water in oil? markings on the head gasket?

There wasn't any water in the oil. The way I could tell was by the white colored residue on the back of the intake valve. I also could see a faint wrinkle-like mark in the gasket.

I had a Cobra intake mated to TFS TW heads and I always had concerns regarding the big port size difference between the two and potential leaking. My new TFS intake is a perfect match to the heads.