Coolant seals bad?
 

Hi, my car has began to throw coolant on the overflow tank everytime I used it, it will fill the tank and eventually throw the excess coolant and not suck it back when cold. Also white smoke is coming out of the car but I didn't smell any sweet scene in the smoke, and also the engine pressurized right away after starting it cold but the engine starts right away in cold or hot, no issues starting. Haven't got chance to do a pressure test since I can't find the tools where I live. Also no sign of a external leak, haven't seen a drop of coolant on the floor. Never overheated while I have own the car, it came from Japan and it have 65K km.

Did my engine have a bad coolant seal?

----> https://www.rx7club.com/3rd-generati...ystem-1068344/

Post #8 has a list of symptoms for a blown coolant seal. The more of those you have, the more likely it's a coolant seal failure.

Yeah, have seen that thread, but most of the symptoms let me to think I have a bad coolant seal but there are some missing like that my car starts fine but I'm not sure if its because is still a small leak that just begin? and the pressure or hydrocarbon test are kind of hard to do here or will take some time until i can get the tools.

One thing that sometimes confuses the issue is that coolant seals, like any o-ring seal, can leak one direction and not the other. In other words, combustion pressure could be forcing coolant into the overflow tank, but no (or very little) coolant is being forced into the combustion chambers. If that is the case it will start and run well, but continue to lose coolant.

DaveW makes a good point. And we can't give a guaranteed diagnose over the internet either. But again, the more of those symptoms you have, the more likely you have a coolant seal failure.

Make sure the hose going to the overflow tank doesn't have any holes or leaks, that can cause coolant to push out to the tank but not get sucked back in. Also make sure your radiator cap is good and the flat cap/spring caps are in the right places.

Dale

Believe the link mentions testing, you can rent a pressure tester for the caps and the system, same device, from a car parts stores such as Auto Zone. I actually purchased my own as it saved a lot of headteacher when finding caps that leak. Adding a little oil to the rubber seal works for me to help cap to seal. Good luck and hope it is something simple.

Another thing to be aware of is the radiator caps with the release lever on the top. In my experience, using the release lever (which is necessary to open that type of cap) can shift the seal off center enough that it will not seal when you put it back on. To get it to seal, I had to screw around with the rubber seal to re-center it. After that, I modified mine (the one on my Pettit AST) to twist off w/o having to raise the lever. Since then it has worked fine.