Guys,

Major problem.
The car started drinking coolant all of a sudden. I can't find a leak anywhere. There's no white smoke from the exhaust, and the engine feels normal. If I cruise on the highway, its fine. If I put any sort of power down (.2,.3 bar)for a sustained amount of time (for example a 5 min 90mph highway drive)... The low coolant light comes on in about 20 minutes...and It takes 1 gallon to top it off...

I can't see anything dripping, I don't see any white smoke from the exhaust (I'm catless). I do hear the belt in the back of the engine squeeking (but its been very humid and raining on and off everyday for the past week..
I noticed that my alternator is at 12v when driving.. It usually was at 13/14 the last time I paid attention.


What do you guys think it could be ?
I thought it was the headgasket at first, but there isn't the slightest feeling of power loss...
I don't smell any coolant from the front of the radiators... Also, the coolant resivour was replaced last year....

 

There's only a few places it can go, on the ground, out the exhaust or in the engine. I'd inspect my coolant, oil and watch my exhaust color. Not even sure if I'd get to the exhaust color, but you ruled out exhaust, that's good.

A gallon is a lot of coolant, I'd drain the oil for peace of mind and take a peek.

Keep us posted!

 

may be one of the coolant hose that starts to leak, coolant may evaporate when it gets on the engine.

If you drive it a bit and then put it in a closed garage, will it smell like coolant?

 

a gallon in 20 minutes would lead me to believe you would notice the the white smoke coming from under deck lid.

 

Pressure test the cooling system. Easy to do and you will find the problem.

 

Since 2008 my car was consuming coolant and finally this winter I've decided to look for it...First got the oil analyzed by Blackstone, no coolant present. Did a pressure test and I had a drop of 1 pound per hour and no visible coolant leak….After I got the engine running at idle until the normal temperature was reached and stop it and start dismantling the filter housing and after the intake assembly. I've found one of the pipe coming from the water pump housing was leaking because the glue was not holding it anymore. The pipe could not go out due to the tight space and short rubber pipe attach to it. There was no leak on the ground but the coolant was just staying on top of the engine and eventually evaporate due heat (the leak was small). Picture is with the alternator removed and the generator bracket removed.... Finally got the engine out and all the 8 pipes welded....

 

i have a similar situation in that i seem to be inexplicably losing coolant level also. i just had the system flushed and coolant replaced a few months back, and yesterday had to add about a qt of distilled water to maintain level and stop the coolant low lights. it has been very hot here lately, and perhaps it just evap's? one constant is that it only happens after hard runs and brisk acceleration and that seems to suck all the coolant into the system(?) and there goes the warning light when low. who knows, no "visible" leaks and the tank and cap have all been replaced in the past. one more thing to keep an eye on!

 

Good call jpflip

I forgot to mention that you could also add dye to the cooling system and use an inferred light to find small leaks. To jpflips point you should pressure test while it it hot or even running. Pressure testing while running is also a good way to test for head gaskets. You can really see the white smoke out the tailpipe while hot and under pressure.

 

Thanks Todd for the info, I didn't know about the possibility of pressure testing while running.