Originally Posted By: mk378
What has checking the radiator every time it is cold found out? If you're losing coolant out of the radiator, is it going into the expansion tank (and not returning), or simply disappearing?
The radiator isn´t full every time I check it, sometimes I have to add 100 cc or less so it comes back to the top. I have noticed that when I add coolant to the radiator to fill to the top after driving the car there is more coolant in the overflow tank so I think the coolant is going to the overflow tank and not returning completely. The problem is that the sometimes the coolant does return to the radiator and it stays full and other times it doesn´t. I might have a faulty radiator cap right?
Originally Posted By: mk378
Another test you can do is have the cap on when cold, squeeze the upper hose and feel for pressure inside. (If there is pressure, loosen the cap to release it then replace cap). Then start the engine and rev it while you feel the hose. If you feel pressure building up right away, there's a leak in the head gasket.
I will do this test it is a good a idea. You can also watch this video putting a funnel on the radiator to check for combustion gases.
Testing Head Gasket Problems
The weird thing is that I put a new head gasket a resurfaced the head 14k miles ago, and in the case it was broken it has been that way for more than 3 months, I haven´t seen signs of coolant in the oil or oil in the coolant, and the coolant isn´t dark as it should be if combustion gases were getting into the cooling system.
Originally Posted By: mk378
The "need restriction" theory is total bollocks. Most industrial systems operate with much faster flow than you'll ever have in a car engine.
So my coolant shouldn´t boil without the tsat?