B16a overheating!
Senior Member
Joined: Jun 2002
Posts: 201
Likes: 0
From: Carrollton, GA
otherway around.... could the excess pressure be CAUSING the leaking coolant in the car? How long and costly is it to change the head gasket? Im willing to do it myself...Also, why is the excess pressure NOT bleeding off from the system?? IE: i can not drive the car for 2 days and still has alot of built up pressure...?
Senior Member
Joined: Jun 2002
Posts: 201
Likes: 0
From: Carrollton, GA
One more thing... if there is a leak in the headgasket, you say the combustion pressure is forcing too much pressure in the system causing the coolant to overflow, correct? Well if this was the case, wouldnt the vacuum pressure on the intake stroke be sucking coolant into the combustion chamber causing white smoke and such?? Thanks man, appreciate the help!
のんびり～(´ε｀)
Joined: Sep 2000
Posts: 2,314
Likes: 1
From: San Jo, Cali
If your HVAC mix is set to cold, then there isn't going to be any coolant flowing thru the heater core. If it's note set to full-cold, and there's coolant flowing to your heater core, then the excess prssure theoretically might cause the leak you're seeing in the cabin.
Changing a headgasket is relatively simple, albeit time-comsuming. The total cost, if you do it yourself, would be the cost of the new gasket, the cost of new headbolts(unless you're running studs), and perhaps the cost of some copper spray. If you work quickly, you could have it done in a few hours, but if you've never done it before, it'll probably take longer.
When you shut the engine off, the hot coolant remains pressurized for a while, until it cools down. Once it cools, it contracts. Depending on whether or not the contracting of the coolant pulls coolant from the reservoir back into the radiator, what you're seeing after letting the car sit may be vacuum in the the system, and not pressure.
It is very possible for you not to see any smoke at all, and still have a blown headgasket. On the intake stroke, the intake valves are open, so the vacuum may not necessarily pull coolant into the combustion chamber as you theorized, since the open valves are a path of less resistance.
If I were you, I would do both a compression test and a leakdown test to see if they can shed any light on the situation.
Changing a headgasket is relatively simple, albeit time-comsuming. The total cost, if you do it yourself, would be the cost of the new gasket, the cost of new headbolts(unless you're running studs), and perhaps the cost of some copper spray. If you work quickly, you could have it done in a few hours, but if you've never done it before, it'll probably take longer.
When you shut the engine off, the hot coolant remains pressurized for a while, until it cools down. Once it cools, it contracts. Depending on whether or not the contracting of the coolant pulls coolant from the reservoir back into the radiator, what you're seeing after letting the car sit may be vacuum in the the system, and not pressure.
It is very possible for you not to see any smoke at all, and still have a blown headgasket. On the intake stroke, the intake valves are open, so the vacuum may not necessarily pull coolant into the combustion chamber as you theorized, since the open valves are a path of less resistance.
If I were you, I would do both a compression test and a leakdown test to see if they can shed any light on the situation.
