Missing coolant from overflow tank

[apolandi]

Hi,had a search on here but couldn't find a problem exactly like mine.

The car is a 95 Zenki S14 with a Kouki sr20det swap.

Last month i noticed my overflow tank started loosing coolant, saw a nice puddle in the water pump area and had it replaced plus a nice batch of sealant.

Afterwards had no puddles under the car and coolant was stable.

two weeks ago i popped the hood to see that my overflow tank was almost empty, rad was full.topped it off and during the past cuple of weeks i see that the car drinks coolant at about a full overflow tank to each 400 miles driven - doesn't matter if boosted or driven normaly.

car never overheats! not before the new water pump and not after! water temp is steady and monitored by a greddy gauge.No water in the oil (dipstick or oil cap)pulls strong as if no problem what so ever.no puddles underneath, checked the overflow tank and it doesn't appear cracked.

what steps should i do next to identify the problem (doesn't sound like a blown HG)? and is it safe to drive it as it is (keeping an eye on coolant level and temp)?

thanks!!!!

[Infinitiguy19]

Do a coolant pressure test and see if it holds pressure to the specified amount in the service manual. If it doesn't hold pressure find the leak as it will be a little easier.

http://Nicoclub.com/FSM

When you replaced the coolant did you purge all the air out?

If not I think thats why its drinking coolant.

[apolandi]

Yes all the air was out before topping it off again...

I looked at the FSM, now if the cooling system wasn't holding pressure wouldn't there be signs of leaks or would it come out as steams instead?And also if the HG is blown,wouldn't the pressure test force coolant into the cylinders causing hydrostatic lock? or is it safe to perform?

thanks for the help!!

[apolandi]

anyone?