This is driving me bananas I posted about overheating the other day. I put in a new thermostat new radiator and hoses yesterday I drove it about 10 miles plus let it warm up no problem. Today I started it warmed it up didnt get down the street and it started getting hot turned around got home it was blowing antifreeze out. Could a coolant seal leak compression sometimes and not all the time or am I missing something. The guy I got this from is a worse barn yard mechanic than me so I am fighting two battles.See you all are going to know me mo matter what.Thanks

 

Blowing antifreeze out of where?

 

Out the cap and over flow. Whats strange it didnt do it the day before and didnt start to over heat. Its done this twice that I know of.

 

filled too high?

 

No I left it a little low just up so I could see level.But whats weird it does not smoke or steam out exhaust at all like I thought a coolant seal would.

 

If you start it cold with the radiator cap off you can then watch for bubbles.
It could be blowby into the coolant passages.

Also is your coolant mixed correctly? If not, then you could be getting
frozen areas in the system causing hot spots that create pressure. If
your not sure drain the radiator at the bottom hose and the block by
opening the drain plug below the sparkplugs and then put brand new
50/50 antifreeze/distilled water in and see how it works. Also keep an
eye on the color. If its blowby the coolant won't stay its orginal color.

The other thing it could be is the oil is not being cooled enough. I you
have a FMOC the oil cooler lines can get pretty bad with age and it
will affect your cooling. It did on mine. My temp guage was at 1/2
mark and then when I installed new lines it stays down less than
1/3 mark rock steady.

 

New radiator cap? Did you burp the system? +1 for checking your oil cooler.

 

Oil heat transfer accounts for about half the cooling on a rotary engine, I recall reading.

 

if its coming out of the cap, the cap isn't sealing. the system wont pressurize with a leaking cap and your car will overheat.

 

It is getting pressure beyond what the cap can handle if you take the cap of it will push it out. The antifreeze mix is right I deliver antifreeze all day.I will check the lines to the oil cooler.I think I am in for fun with the coolant seals.Thanks