I have a problem with my radiator and antifreeze, What could be the problem?

Hi guys I have a Honda civic lx 97, I bought about 7 months ago, since then I have bought a new radiator because the old one had a huge leaking problem, anyways I never new How long a gallon of antifreeze could last me. I now know I use too much (I've bought two gallons once the first time i changed the radiator, again today[spand time of 4 months]) antifreeze I don't see any leakage, what could the problem be?

2003 honda civic overheating at idle?

I have a 2003 honda civic lx with 229k miles on it. Last year i noticed that it started overheating at idle but cools down again when i start moving. So i replaced the radiator, timing belt, water pump, and valve cover gasket(because it was leaking oil). This seemed to solve the problem for the whole year until a month ago i noticed it started doing the same thing again. It seems to go away when i top it off with coolant then about a couple days later it starts doing the same thing til i top it off with coolant again. There are no visible leaks. So far this is what i've done to diagnose the problem with no avail.

1) pressure tested the head gasket, everything seems fine
2) radiator holds pressure when i had a pressure test performed on it
3) engine oil doesn't look milky
4) no white smoke coming out of my exhaust
5) no visible oil leaks. Overflow resevior is full

I had a trusted mechanic suggest it could be a blown head gasket.

Estimate/average of power window repairs?

I have a 1997 Honda Civic EX Coupe 2 Door. Both my driver and passenger windows do not work. I have replaced the motor & regulator, replaced the driver's door switch, and checked the fuses. I know location prices varies. I'm just looking for estimates or averages of prices so I have a sense of how much I should save up for.

Honda is reading po135 but o2 sensor changed(twice), check engine light still on?

My Husband and I bought a car. 2004 civic coupe LX automatic. Check engine light came on, we got it read and it came up po135, a code for camshaft position sensor intermittent signal and the Electronic load detector. We got everything we needed and bought some extra tools. My husband fixed the timing belt that was just changed previously (it was off a tooth), changed everything it said to fix, but the code is still on. He went to a dealership, had it reset, drove home engine light went back on. We tested the O2 sensor it was good but replaced it just in case. My husband checked the wires for the circut, everything was fine from what he could tell, He checked fuses, tested resistence, checked for a open or grounded wire, basically a lot. The P0135 code still comes up. My husband suggests a new PCM install it, big surprise, not the PCM. The car runs just fine and other than the check engine light you would not know there's a issue. Is their anything else we could do before we spend hundreds of $ we do not really have to get this car on the road? Its too late to sell, we have lost so much money might as well go for fixing the darn thing.

Newer Honda Civic idle low/uneven - would fuel system cleaner

All of a sudden I keep noticing that the idle on my Civic is low or uneven and it seems like it might stall out sometimes. I'm wondering what different things it could be and could it possibly help to use on of those additives that supposedly clean the fuel system.

Too much oil in engine, white smoke?

I excessively overfilled my engine with oil (more than 5 quarts) in my 2001 Honda Civic EX. I drained the excess oil out after the car would not allow me to acclerate. After draining the excess oil and refilling it to its correct levels, smoke keeps coming out from the exhaust when the car is idle and when I drive it around the block for several minutes. The smoke is rather light in color (almost white or light grey). What could possibly be wrong with my car and how should I go about this?

Bad headgasket, Why is my coolant not returning to the engine?

I know I have a bad head. Anyway the coolant overflows out the overflow tank and fails to return to the engine. Figured that CO2 was displacing the coolant and the vacuum created when cooling then was minimal. BUT, when i removed the coolant overflow lid and took the little hose in it and exposed it to air THEN removed the rad cap. My lower and upper hose collapsed/sucked in. What does this indicated?

Added (1). BTW it is confirmed with a block check chemical test. 2000 Honda civic Dx. Aluminum engine. Car overheats only intermittenly after long drives and coolant only needs to refilled because it is overflowing. Also my thermo is working as well as fans.