Coolant is just disappearing. Not a wisp of smoke from the tailpipe, no puddle underneath, it just disappears a quart in 50 miles. Overflow tank doesn't fillup. Can watch it with the rad cap off and nothing happens. I just put in new radiator and hoses because it was using a cupful every week.

B

 

Hmm, its not finding its way into your oil, is it? Other than that, I'm drawing a blank here...

 

same thing happened to one of my old fist gen's...

turned out the rad cap wasn't sealing properly, and i was losing coolant from evaporation....got a new rad cap and it stopped

 

I had the same problem in my '83 GSL. It eventually stopped losing coolant on its own after buying extra coolant, I pop the cap off after driving it for a few days only to find that it stayed full for the first time since it started. Now if only I can find out where the rest of my fluids are going to.

 

when was the last time you pulled the intake manifold off? if your o-rings around the coolant passages are not sealing well enough, it will seep in to the motor and burn off. but it's not enough to create smoke..... this is what happened to me. easy fix

 

 

Now I suspect the radiator cap. Part of the reason is that the overflow bottle is almost empty (I topped it up when I discovered that) which suggests water/vapor is blowing out thru the neck (maybe bad rad cap seal). I had a similar problem on another 7 and it was fixed with a new rad cap. think I better order an OEM cap from Mazdatrix. In the meantime I put the 85 in the fixit bay so I can run it up and down and carefully monitor for leaks, etc.

I don't think it's the internal water seals because usually one gets clouds of white smoke at startup. But I can sorta see how the manifold seals might do it of they only leaked when the engine is actually running so that no water stores up in the engine to give the telltale white smoke at startup. Anybody have this experience?

B

 

I took the opportunity to order a couple rad caps (the SE has a lever-operated cap: that can't be OEM!) so in a few days I'll be ready to test that.

I will inspect the manifold O-rings in a while when I get the Sterling carb for that car.

B