Losing coolant.. where do you guys think its going?

[fragzem]

Let's start with this:

I live 5 miles away from my job. (and its a straight run, 65 mph highway 99% of the way)
There and back, maybe 2 or 3 times a week.. I end up losing about 1/2 gallon of coolant.

So.. no drips in the driveway, no water in the oil, no white smoke to speak of.. where is it going?

Is the engine just burning it? Perhaps a valley pan gasket issue?

182k on the odo

[JimLev]

That's a lot of coolant in 30 miles. It's gotta be going somewhere. Drop the lower engine cover and take a look underneath. If it was going out the exhaust you should see some nice steam trails. You should also notice ruff running when you first start it up, if it was getting into the combustion chamber.

[Cereal]

Valley pans can be sneaky but mine would make almost a popping noise under the intake manifold when the car was hot. It would leak and boil off

If you arent dripping, oil is clean, It must be leaking and burning up unless it is coming out of the exhaust and you just cant tell? It is really cold out and probably hard to tell cold weather smoke from coolant smoke?

[kapetajr]

Crack in the radiator somewhere? Maybe look under the hood while the car is running.

[edjack]

Pressure-test the cooling system while hot. There's a leak. The V8 test pressure is i.5 bar, or 22 psi.

[Mels5406]

+1 on the lots of water loss. Possibly losing water through the water pump weep hole? A failing water pump could be the cause.

[topaz540i]

Can you smell it burning at all

[fragzem]

Can you smell it burning at all

nope, don't smell it..


+1 on the lots of water loss. Possibly losing water through the water pump weep hole? A failing water pump could be the cause.

checked waterpump when we did alternator in November.. seemd okay, not making noise, pulley was solid..


Pressure-test the cooling system while hot. There's a leak. The V8 test pressure is i.5 bar, or 22 psi.

good to know, this is what's gonna have to happen..


Valley pans can be sneaky but mine would make almost a popping noise under the intake manifold when the car was hot. It would leak and boil off

If you arent dripping, oil is clean, It must be leaking and burning up unless it is coming out of the exhaust and you just cant tell? It is really cold out and probably hard to tell cold weather smoke from coolant smoke?

it is cold out, but i'm not getting smoke from the cold either..


That's a lot of coolant in 30 miles. It's gotta be going somewhere. Drop the lower engine cover and take a look underneath. If it was going out the exhaust you should see some nice steam trails. You should also notice ruff running when you first start it up, if it was getting into the combustion chamber.

ha my lower engine cover is so torn up i could probably just look thru it.. seems to run alright on start-up.. I HOPE its simple like the radiator.. last leak I had was the heater control valve, which.. I found for a decent price used on eBay from a 60,000 mi vehicle. if I can continue to be lucky.. that'd be nice. Monday I suppose I can get this into the shop I work for.. because I work day and on-call at night, its difficult to find time to do these things myself..

thx guys. appreciate all the insight, will let u kno what happens..

[mathaiser]

Pressure test that thing. Or just replace the whole cooling system. Ha. Kind of not even kidding. When you open your hood There is no coolant showing. I assume you have looked at you radiator and engine from below without the under guard on.... So if its not there, then it might be from your heater core hoses behind the engine,(take off both cabin filter housings to get better access). Then if you don't see any coolant there, it's probably going out your tailpipe. Check you oil for milky residue if the oil and coolant are mixing. Watch your tailpipe.... It takes a lot to lose 1/2 gallon in that short of a trip, you use just a gallon of gas, I'm sure it would be noticeable.

Not sure what the symptoms of valley pan gasket are. Maybe freeze plugs on the left and right lower sides of the engine are only leaking under pressure and not when cool, but that would probably be ruled out because if no coolant on the ground

[RocketSurgeon]

One thing that might show the leak for free is drop the bottom cover, then drive around for a few minutes to reach operating temperature (and pressure). Then park on the driveway and idle for a few minutes. It may only be leaking under pressure.

[Gumbi4u]

Did you check your ass? Coolant tends to end up there sometimes.

[adam1979]

I don't think the valley pan gasket would lose that much coolant. They tend to seep more than leak. I've been driving around with mine leaking for over two years, and I only have to add a cup of coolant maybe every 1000 miles. Take the engine cover off and look behind the intake manifold on the right side of the engine. You can see a small coolant puddle there if the valley pan gasket is leaking. I started a thread with a picture of it a while back - I can dig it up if you want clarification.

Expansion tank is also suspect. I went through 2 of them in less than two years, and neither left coolant on the pavement. One of them blew out the bleed screw and the coolant escaped at the top under pressure.

[RVAE34]

I would get a leakdown test done. I always prefer leakdown over a compression check.