The radiator cap was replaced with the radiator...its band new and the condition hasn't changed since changing the radiator and cap.

 

If you are confident that the radiator cap is not faulty, then overflowing of the reservoir could be caused by engine over-heating or coolant system over-pressurization caused by entry of exhaust gas into the cooling system due to a bad head or head gasket. Given that you haven't noticed any over-heating lately, the latter possibility seems more likely, leading again to the bad head/gasket theory. The circle continues.

 

ahh, now it is becoming clearer. I'm going to drive the car another week before I go back and get the thermostat put in. I guess it is the head/gasket. oddly, the guy at the Honda place said it isn't really a weak spot on these civics. sucks for me.

I suppose the over-pressurization could also be shown by the way the system remains pressurized even after sitting a few days?

Sorry for the circle, I'm just trying to make sure I don't drop 800 on something that isn't necessary or won't even fix the problem. That would REALLY suck.

 

I apologize. My questions and comments are meant to help rather than make the situation worse. It's clearly a tricky problem.

My point is that, because nearly every possible scenario for an over-heating problem has been covered in this thread, one (or more) of the already mentioned components is most likely at fault. The question is which one? At this point, making the assumption that a recently replaced part must be fine limits your ability to solve the problem. You now must assume that any logical cooling system component (new or otherwise) mentioned in this thread could be the cause of your problem.

I also think that, in general, conclusive tests have not been done on your Civic. For example, what rigorous tests led Honda to conclude that the head/gasket was bad. None that I can tell. I would ask for a refund. With all of the money thrown at mechanics thus far, you really should have a good idea about the cause of the over-heating problem. It's unfortunate that you don't.

 

its probaby the head gasket that is worn out...or its probbaly one of your pistons has a crack on it and anti-freeze is going into your engine and most likely if that happens you might need your engine replaced...what i would do is get a compression test done to see where the problem is coming from. you can also just spend $100.00 to find out what is the exact problem by taking it to a honda service center and getting a FULL diagnostic test done. what i would recoomend for you to do, is to get a new radiator, new hoses, new thermostat, thermostat switch, new water pump (could be that it messed up due to constant overheating) and alot of anti-freeze. when your car overheats like that is probably telling you to add some more anti-freeze (next time your temp. shoots to (H) open the hood and pour some anti-freeze and watch the temp go down.. if that doesnt work then ITS DEFFINATELY one of your sensors. probably ur o2 sensor...or sumtin like that.

 

Compression test was A-ok

Car overheated again today after a 30 min traffic-ridden drive. Mechanic says the overflow is either the rad cap (unlikely as it is new and same crap happened with old radiator/cap) or the head gasket.

Looks like I'm spending 700-800.

 

a. Do not let the gauge go up to (H) in any case. Once it starts to move above normal, pull over and stop the engine and let it cool off.

b. NEVER EVER open the radiator to pour in coolant when the engine is hot. Though a new engine is kind of expensive, it is nothing compared to ER bills.

 

With my car, I can just rev the engine and the temp goes down....it's all kinds of messed up!

 

Ok, car is with the shop. I hadn't driven it since tuesday when it overheated. Before I took it to the shop today I popped the hood and opened the rad cap. As usual, there was pressure in the system that came out with a "whoosh" and fluid. The coolant was at MAX level and the reservoir was FULL...even though the car hadn't been driven in 2 full days.

Weird things bro's, weird things

 

So is the plan for this shop to replace the head gasket? Good luck. I hope the mechanic fixes the problem for you.