I decide to check my car this morning before driving it today and noticed that the coolant was kind of low in my radiator filler. It was about 2" below the fillerneck/radiator top, but could see some coolant at the bottom. I checked my AST cap and the coolant was filled to the top and the overflow was at the correct line on the dipstick. I then checked my oil dipstick and that was fine. But when I checked the oil cap, I noticed milky residue on the cap and part of the filler neck. From my previous experience with piston motor, that a sign of leakage from the water lines to the oil lines. Anyone know anything about this?

 

It's usually a milky white/gray slop when the oil mixes with the coolant. Not good, but until you see it get worse or water in the oil, I'd keep driving it. The damage is done.

 

The only thing I can count on is that I just purchased the car about 2 weeks ago and the previous owner had the motor rebuilt by Mazda and the warranty on the work is 1 year or 12000 miles, he only had about 2k miles on it since.
I'm just hoping that Mazda would warranty this without a battle

 

A little condension in the filler neck is normal in a rotary, The filler neck is the high point of the oil sump so moisture tends to collect there..........

 

Would condension create that milky substance in the oil cap?

What would be a sign of gaskets/seals going bad? I heard that your motor runs like crap on a damaged apex seal, but what other signs of determine a problem?

 

yep. that is normal. freaked me out the first time i saw it too. if the frickin search worked you could probably search for a bunch of other threads like that.

 

Hey Albert, you sell your car yet? I do kick myself in the *** not getting yours, but my check was about to expire and our schedule weren't matching

 

The milky stuff is normal. There is poor crankcase ventillation in the rotary (there actually isn't a crankcase, but we need a correct term - perhaps oil cavity ventillation). Watch out for this milky stuff, it's acidic! You can easilly get rid of it. About once every week or two, after warming the car up thoroughly (going for a drive), pop the hood and remove the oil filler cap. Leave it off overnight - if you park in a garage leave the hood open, if you park outdoors, leave the cap on the dash. This is to remind yourself to put it back on before you start the engine. You will find all the stuff will evaporate.

The RX-8 gets it on the dipstick. It creates lots of consternation in those owners as well.

 

Like he said it's normal and increases due to poor ventilation.

Using a catch can will help.