?? -LOW COOLANT- ??

[will_95gt]

Ok, a few weeks ago I noticed my Low Coolant was illuminated. A few days later I got the oil changed and had them top off the coolant. Well, its only been two weeks and the low coolant light is back on

My first thought was a leaky head gasket; this is because, if I remember correctly, my car's previous owner had a similar problem. So, here's my question:

How can I tell where my coolant is leaking from? Also, if it is a leaky head gasket, is it easy to fix and why would it happen again within a few years? Cracked head?

Thanks guys,

-Will

 

[Bosko5.0]

Iam in the same situation mynes been on for 3-5 days last time it came on was a couple months ago.

 

[94GTCoupe]

check around your hose's for any corrosion,you can tell they are leaking if you see a white powdery substance.if it's a slow leak at the hose's,it can be easy to over look,and it won't leave a puddle under the car because it will burn off on the engine.

 

[Chythar]

The low coolant sensor is in the overflow reservoir, and it can get corrosion on the sensors. Is the reservoir actually empty? If not, time to clean the sensor.

Low coolant can be caused by a leaky head gasket. But it can be caused by a leaking hose, a cracked radiator or simply a bad radiator cap. Check all the hose clamps, make sure they're all nice and tight. Make sure the petcock is closed nice & tight (drain valve on the bottom passenger side of the radiator). I'd also replace your radiator cap if you haven't in a while.

You also might want to get your coolant system pressure checked. If there's a leak, it won't hold enough pressure and it will leak. Our radiators tend to crack on the passenger's side, it's a flex point in the chassis. If your radiator is kinda old, that's another possibility.

 

[will_95gt]

The low coolant sensor is in the overflow reservoir, and it can get corrosion on the sensors. Is the reservoir actually empty? If not, time to clean the sensor.

Low coolant can be caused by a leaky head gasket. But it can be caused by a leaking hose, a cracked radiator or simply a bad radiator cap. Check all the hose clamps, make sure they're all nice and tight. Make sure the petcock is closed nice & tight (drain valve on the bottom passenger side of the radiator). I'd also replace your radiator cap if you haven't in a while.

You also might want to get your coolant system pressure checked. If there's a leak, it won't hold enough pressure and it will leak. Our radiators tend to crack on the passenger's side, it's a flex point in the chassis. If your radiator is kinda old, that's another possibility.

Ok, the radiator is about two years old, so are the upper and lower hoses. I started the car just now and the low coolant light didn't illuminate; I figured it might not because its pretty nice outside and the coolant light usually comes on only when its cold.

Anyways, I popped the hood and checked the upper and lower radiator hoses (the seem pretty snug). Then I noticed a drop--just one or two eyedropper drops--of green fluid on the top of the radiator just below the hose that goes from the radiator cap (silver cap on the right) to the reservoir (on the left). I pulled on the hose and it slid off the nipple by the silver cap with ease. There also seems to be some orange build up around that area that I'm thinking could be from coolant that has dried and sort of crusted.

So, my question is:

Is it common to have some coolant residing around this area or is this probably my leak? If it is, what do you think is causing that small hose to not make a good seal with the nipple? The hose looks to be in decent shape, should i buy a new one from O'reilly or something?

Thanks guys,

-Will

P.S. Chythar, great post! Thanks a lot.

 

[will_95gt]

Heres a pic' to illustrate my description:

http://s14.photobucket.com/albums/a311/will4fang/?action=view&current=radiatorhose.jpg

 

[nisreo]

Check under your oil cap for any milky residue. If there is some, but your oil comes out clean, thees a good chance when the headgaskets were done, they didnt apply sealer to the lower head bolts threads. From what Ive been told the lower bolts on the heads thread into a water jacket in the block. If you dont seal them before putting them back in, coolant will leak into your heads and burn up. Hence the milky oil cap and baffle and clean oil. I was told by an old time engine builder that Permatex #2 is what to use to seal those threads. It comes in a tube or bottle.

 

[will_95gt]

Interesting idea, nisreo. What do you think about the leak i was describing earlier?

 

[95riosnake]

If not, time to clean the sensor.

Did you try doing what Chythar said? I had the same problem a few years ago and that was the problem. The way it senses the coolant level is there are two electrodes on the sensor that goes in the overflow bottle, the coolant conducts electricity and "connects" the two electrodes. If they are not "connecting" to each other because of a buildup of gunk, the sensor will trigger the low coolant light.

 

[Bosko5.0]

put a hose clamp on that and it should stop the leak.

My leak seams to be the rad the bottom 3 fins were wet.

 

[will_95gt]

Ok, thanks for the responses guys. Rio, I'll have to deffinitely check out the sensors on that reservoir, are they easily accessible? The only thing is that its only reading low in the cold. If the sensor was dirty it seems like it would be reading low constantly.

Bosko, good thinking with the hose clamp... I suppose that would be a good temporary fix but I'm still curious as to why that leak began in the first place. Could the leak have been caused because of extra pressure for some reason in the coolant system?

Thanks a ton guys,

-Will

 

[Chythar]

The leak is likely caused by an old rubber hose. They do wear out eventually. A hose clamp will definitely fix that leak. You'll have to make that fix and see if the problem goes away before you know for sure it was the cause of your low coolant.

In case you don't know, the coolant system is pressurized. When the coolant gets too hot (and the pressure in the system gets too high), the spring in the radiator cap compresses and coolant flows into the reservoir. When the coolant cools down, coolant flows back into the radiator through that leaky hose until the radiator cap spring closes the system off. So you're slowly losing coolant through that leak and letting air in the system.

 

[will_95gt]

Ah I see, very informative Chythar, thanks! I clamped the hose on tighter and it seems to be keeping dry now. I just have to top off the coolant--I'll let you guys know what happens next.