Hey guys,
Just finished rebuilding and upgrading my engine (mild to wild street-port, t70 turbo, 50mm wastegate, BOV, FMIC etc). But now, no matter how much coolant I put in, the radiator never fills up!! No visible leaks can be seen from the engine...car is starting and idling. Can anyone offer advice??

 

The coolant cant be going nowhere -

either its leaking (im sure you would notice if it was any substantial leak)

Its burning coolant (if it was burning that much, im sure you would smell it)

or you havent managed to fill the whole system yet.
Try the below procedure to make sure ur coolant system is indeed full. It takes about 9 litres of coolant.

Take off the coolant filler cap, take off the throttle body coolant line, and the top to the overflow tank.
Add more coolant in filler neck, add more coolant into overflow tank. Make sure you pulse the lower radiator hose as you add coolant at the filler neck to make sure you get as much air out as possible. Keep adding coolant till coolant comes out the throttle body coolant line.
Re-attatch throttle body coolant line- then try add even more coolant by pulsing lower radiator hose.

Start Car - let it warm up so the thermostat opens.

Turn car off and let it cool down.
Check coolant level and add more if needed.

If that dosent work you have a real problem (coolant dosent just dissapear) - your leaking coolant or even worse burning coolant in your new engine.

 

Are you sure you have burped it all the way. If you deleted the AST it does take some time to fill it all the way. Let the car warm up, then cool down, top it off and repeat until the coolant level no longer drops.

 

Nailed it right on the head!

If you're really scared you can only do two things to confirm. One is buy a coolant pressure block to mount on the front iron to pressurize the block and check for external leaks. If there are no external leaks it means your coolant seals are damaged or moved out of the ridge.

Second is to simply use a pump to pressurize the whole coolant system and check for leaks. If there are no external leaks take out your spark plugs and keep pumping most likely it will come out of a spark plug hole. If that happens I don't think I need to tell you the next step....

 

how exactly are you checking the radiator? FD radiators don't have a way to check if they are full...

If you mean that you aren't seeing fluid at the water pump fill point, then keep burping and filling as the other guys stated. Filling this car with coolant/water takes forever...

 

Try my steps here:

https://www.rx7club.com/showpost.php...21&postcount=4

 

Thanks a lot guys!! As soon as I get back home I'll attempt the necessary procedures/checks that you suggested. I'm currently out of the country.