Where is my coolant going?

[deejay1272]

I've noticed that my coolant reservoir level drops dramatically after a few hundred miles of driving. Since I've never seen any evidence of a leak and I haven't noticed any coolant in my oil, I'm assuming that it's being burned somewhere in the combustion process.

Does anyone have any ideas about what could be going on here?

[Neu]

Check your exhaust. If it's a little "foggy" or white, tends to last longer than it should, especially on a cold day. It could even smell a tad like coolant.

You could have a blown head gasket, the usual reason for losing coolant.

[takza]

Check here...

viewtopic.php?f=7&t=6039

[deejay1272]

Thanks for the tips. I will perform some/all of these checks, but I have this sneaking suspicion that the head gasket is at fault because my exhaust is a bit "foggy."

However, I did achieve between 185 - 195 PSI in a compression check that I performed ~4,500 miles ago.

[Logbear]

I had a similar problem. I would drive to work and back (80 miles), and after a few days I would notice my coolant was low. I'd fill it up, the car ran fine. Then I would notice the temp getting a bit high, so I would add coolant and be good for a few more days. I never actually saw a leak or evidence of a leak. When I really investigated the problem I found a small drip coming from the water pump while the engine was running. It wasn't much of a leak. I figured that it took about 8 hours of high RPM driving down the freeway to leak enough to notice. Less than 1 gallon in 8 hours. Less than 1 pint an hour.

Anyway, I found that the problem was the water pump. When the water pump bearing is going out, there is a weep hole that water drips out of when it's spinning.
I replace the water pump and that solved the problem. I would suggest putting a new thermostat in too since the coolant will be drained.

I thought I had a bad head gasket once too. I used Barrs leak and the car runs fine now. 352,000 miles and going strong.