OK, not really an offroad question, the ranger is my 2wd daily driver - 56K miles. But a strange problem has started occurring, wondering how common it is. Noticed a couple days ago that the overflow bottle was completely dry. Filled it and the radiator back up, about 3/4 gallon. checked it again today and I'm down about 1 inch in the overflow.

Seems to be running fine, no collant in oil, no big clouds of steam out the pipe. Did a web search and found a couple posts about the same type of problem with no solutions.

Any ideas? I'm going to pull a couple plugs tonight to see if there are any deposits on them, but other than that I'm stumped.

Thanks

You may have a head gasket on the way out. The heater core may also be leaking inside. check the carpet for dampness. Also check all the hoses with the engine cold and hot. Sometimes they only leak when cold or vise versa.

These things can be a real pain to track down sometimes.

You also might want to rent a coolant system pressure tester and check for leaks that way.

You may not have any problem at all. I know both my vehicles occassionally need to be topped off. Depending on the temperature outside, the coolant will expand or contract accordingly.

i agree with the heatercore thing.. maybe a seal or something.. check the carpet and underneath the dash... most likely on the passenger side. have this same problem with a 1986 300zx.. only leaks when i use the heater or ac or anything

I had the same thing, turned out to be a slow leak in the radiator.

Replace the Rad. cap and then get some leak stopper for your coolant. It will seal any minor imperfections in the seal/block that is letting your water evaporate