Ok bone stock four door civic lx. OK so what happens is ill fill up the radiator and after a few days of driving ill pop the hood to check my coolant level and it will be really low, so ill look at my overflow which was empty when i filled the radiator and that has all the coolant in it from the radiator. So i replaced the cap that didnt fix anything. No signs of burning or leaking, or i know as a fact it is not burning or leaking. Just pushing coolant into overflow making my radiator lose coolant. No symptoms or a bad HG either. What could be my problem? Thanks!

 

Sounds like yet another headgasket issue to me.

 

Sounds normal. Start the motor and when's it's at normal temp, take the cap off of the over flow tank and look for bubbles coming from the hose. Blown head gasket

 

No bubbles. Could I just elimate the overflow since that's where my coolant is going?

 

No, Honda designed that coolant system to include the reservoir for a reason. You should start looking for a replacement motor

 

Have you checked the oil?

If you have to fill up the radiator, then you are losing coolant. So you can't say you "know for a fact".

When the radiator gets low on coolant, does the car overheat or go above the normal operating temperature? Temp for ek's is right about at the half mark on the gauge.

 

check the oil.

 

Yes it's starts to run hot that's when I immediately shut the car off and empty the overflow into radiator. The oil is fine no leaks and no mixing

 

Only runs hot when idling when coolant gets low

 

When hot enough due to driving conditions the seal between the block and head fails.
Based on the information:
No Leaks
No coolant in exhaust
Refill after a couple days

I would bet money on your head gasket being faulty. The car will continue to run with a blown head gasket. Over time it will get worse. This is common in old Hondas.

Edit:
My 99 EX when I got it had the exact same symptoms. I beat on my dying D16Y8 for a year+ before doing anything about it. You may have time to decide how you wish to proceed, or it may blow tomorrow. Start planning

 

I only have to refill because its going into my overflow

 

An expansion my explanation above:
When the engine is hot enough due to driving conditions/load the seal (head gasket) between the block, and cylinder head is failing. Physically the head and block have warped due to the heat, or the head gasket has corroded. Either way the head gasket can no longer form a seal around the cylinders. This allows exhaust gas to enter the coolant system. The pressure from the exhaust gas pushes coolant into the overflow.

Do this:
Check or smell your overflow tank for exhaust gas when the motor is hot, and your overflow is bubbling.

 

fill both and see what happens

 

sounds like when i first had my car, no mixing of coolant or oil but crazy overflowing but then i replace my headgasket the motor is fine and no more extra pressure and coolant lost

vehicle was a 1996 honda civic lx 4dr

 

No bubbles in overflow tank. If I fill both it will leak out of overflow

 

the only way coolant will overflow through the reservoir is a blown headgasket.

 

My car was having those exact symptoms since I got it over a year ago, it even had a leak which I corrected last weekend when I had to replace water pump, timing belt, and in the process I replaced the thermostat. I will see if the coolant continues to over flow to reservoir. Because like the OP, my car is not smoking or mixing oil/coolant in the next couple of days so I can get check by a mechanic.

edit- My car is a 96 Lx with a D16Z6 swap that was done by previous owner. but I dont think it makes a difference since the EK and EG cooling system are almost identical in the side of the engine.

 

This is not the definitive sign of a headgasket being blown. Just because you don't have these doesn't mean that it isn't.

 

what other signs or symptoms should I look for ?

 

Test for exhaust gases in the coolant. Leakdown tests.

 

I had the same exact problem, it was a leaking head gasket.

Here's an easy, cheap way to confirm.

- Drain all radiator fluid and remove thermostat and detach overflow tube from tank and put everything back together nice and tight
- Fit a balloon in place of the radiator cap(i didnt have a balloon so I used a condom, i had plenty of those laying around) and plug the overflow hose (use a bolt)
- Remove all spark plug wires except 1 (starting at the first cylinder)
- Crank your engine over and watch to see if balloon/condom moves.

Do that for all cylinders one at a time. If you see the balloon move (even the slightest bit) your head gasket is leaking from that cylinder.

 

Thanks, I will see if I can do that test this weekend.

 

Yeah I have bubbles now in overflow tank when I rev it a little. Doing a hg this weekend!

 

That's bad luck, but I told you.

 

Yeah I know. hopefully it goes smooth and fixes my problem