Eric, Have you changed your waterpump before? check the thermostate on the return coolant to the engine. Normally the door will be closed, but when it's hot it will open. hose from engine to radiator (top) see if there's any leaking or vapour.

You can do much cheaper for gasket changing. If you're going to change the gasket, mind as well change the cam seal (this one normally will leak after years). Save labour cost on bukak rocker and head. I can recommend one shop as I did my gasket and cam seal change out there. Now double gasket . No leaking issue.

hopefully ur car will be cure~! Wish u luck~! 

why u keep saying blacktopp?

you three are bonding. hahaha.

I also noticed my sis's blm hitting above mid. but that's after a long drive and the engine is hot and not running.

gasket sealant ar... hmm.. can try, but i think it's a big hole,  sealant ain't going to help much. You said a single drive can drain the whole reservoir. its pretty much serious.

Do compression test to see if the gasket is leaking. its not cheap, but at least it's cheaper than blindly change something which is not faulty and yet still haven't solve the problem.

old saga? or iswara? or kancil?

U told me 7 =.= Even im already late but still too early