13b building pressure in cooling system
 

my 93 rx7 13b motor has a 60-1 turbo with a greddy intercooler setup,running 8 psi boost,no overheating,car can reach 180 mph easily and stay there with no fluctuation in normal temp, a koyo radiator mounted upright but tilted forward slightly,( not 100% upright or straight up,angled),and I am loosing antifreeze when the car stops at a light after running about 30 miles non-stop,the motor seems to be pushing out the antifreeze out of the overflow hose that goes to the brand new overflow/reservoir tank newly bought,with all new hoses,we did a pressure test and it lost a little anti freeze,I know my cooling seals are going,but my big question is this,do I have to install an air separator tank in the system,since the cooling system is definitely building some pressure.Neal10

First, welcome to the club. Second, you posted this in the wrong section. You also shouldn't be running around @ 180mph (but on 8 psi? Baby Jesus says: ROFL). The way the radiator is mounted is standard for the FD. If you coolant temps are fine there's nothing to worry about, it's normal for any car that's been ran hard to have coolant going to the overflow reservoir. The air seperator tank just aids in removing air from the cooling system. So as far as having to install one, no, but they are nice to have.

Does the car still have the stock radiator caps or ones rated for stock psi? If not it's going to put more pressure on your already bad coolant seals. Get a 13psi (.9 bar) cap. If you are sure that your coolant seals are bad then that also means the cooling system won't be pulling the coolant back into the system which would exlain the system overflowing. Have you having to add water constantly or have your buzzer go off?

13b building hi pressure
 

Yes I have to add coolant after engine cools on shutdown,about 12oz.Where was I supposed to post my question?

In the 3rd generation section =) https://www.rx7club.com/3rd-generation-specific-1993-2002-16/

check your cap. then your radiator. start with the easy stuff first

i dont thing this has anything with the subject...
but what exactly is the difference with the re 13b in an rx8 and the 13b in an rx7?

you have a crack on one of your water gaskets!! i had the same problem good luck with the rebuild cause thats what you need.

I think you mistook section for a general rx7.com section

it used for the vendeor Rotary Performance Rx-7.com

lilzander is rigth,or one of your cooland seal are bad or one of your front or back plates are bad that happen to me so good luck with the rebuilt,where you live I know a person the know rebuilt engine and is not expensive bro.

I know that this is a little late... I just thought I'd add a quick post.

Before replacing your engine or other major parts, you might want to bring the car to an experienced shop and get a 2nd opinion. Sometimes these things are much more simple than we expect.

We would be happy to take a look, just make sure to call first.

Take care,
Ari

u sure its not a slit on the overflow tank??

drive till the car is hot/warm, and leave the engine running at a spot u can work on.

next, pop the hood, and use the wire that manually revs the car. rev it hard enough, and u should be able to see where the leak/ is coming from if there is any.

i had the same problem, but mine was just a crack on the slit of the overflow tank, and needed a brand new one.

AKA BRAND NEW ONES STILL NEED TO BE TESTED!
could be defaults on them.

TRUST ME ITS A CRACK IN HE WATER GASKET. as the rotors are turning the build pressure, the crack is taking in pressure there for pushing all the water out of the motor filling it with air.