My Honda civic has been great. Just recently when driving the car it overheated(gauge went to 3/4) and I pulled over and overflow was at min but rad was almost empty. This has done this now 3 times over the last week. From what I can see there are no leakages from rad. I have read the forums on overheating and checked for coolant in transmission...theres none. Checked oil level is same no increase. All the leakage is coming from the overflow. checked overflow pdf from http://www.tegger.com/hondafaq/tsb/civic/x00-025e.pdf
wasn't that.

thanks for your help

 

Coolant in transmission? If you're not leaking it, you're burning it. First thought with these old cars is a failed headgasket.

 

I am leaking out the overflow. no leaks in rad and not burning it either. The car runs great lots of pep still and no other problems.

 

Ok. Fill the radiator + overflow tank and floor your car above 4k RPM with gear 1 or 2. Check if you see coolant all over the engine compartment or around the overflow or both. If so, your head-gasket is toasted. Your engine will slowly lose performance. Hard starts, misfires, shaky/rough idle, loss of power. They are not in order but they will happen. Also, you'll have a lot of overheat after driving on freeway.

 

Are your fans activating? How does you radiator cap look?

 

out of any of these 3 times you re-filled the radiator have you burped the cooling system?

also I don't see how under ANY circumstances. Coolant will enter the transmissions. unless it's leaking so damn bad you can't put coolant in fast enough.

LOOK UP COOLING SYSTEM BURP PROCEDURE
the procedure is common there's nothing to complicate the burping on this car.

 

uhm don't do this ^
I can't believe people would suggest such idiotic things. This is probably why these are beginners cars(inexperienced kids own them who take advice from their "mechanic" friends then relate it to you).

 

My fans are working. I never burped the coolant system yet but will go and do it. The radiator cap looks good but I am going to get one anyway.

 

well since you emptied, refilled the system 3x now. im sure it's so backed up with air the only place for it all to escape since there's nothing wrong with the cooling system is via overflow tank

burp the system it will be fine.

leave the cap alone until the seal dies.

 

here try this
http://www.hondacivicforum.com/forum...leeding-41650/

 

I'm sorry if my advice offended you in any ways to the extend of being called an inexperienced kid with idiotic idea. OP obviously stated that coolant started loosing out of nowhere. As grumblemarc stated

This is the fastest way to test the basis of the leak/blown gasket, instead of pressure testing with the pressurizer at the shop. But that's alright. OP can take your expert advice.

 

Auto transmissions have the trans coolers built into the radiator, if those areas in between are beached they can mix.

 

Running a test to determine if exhaust gasses are getting into the coolant is relatively quick and painless. So are compression and leakdown test when performed correctly. I don't think I would advise any course of action that induces worse performance to the engine as a diagnostic tool.

 

so I burped 99 honda civic lx 1.6 sedan, radiator cap is fine, thermostat is about 5 months old, now for the first time my antifreeze came out under my car and was smoking from the far right side. Any advice? I have 259,000 miles on this car.

 

Next time start a new thread instead of bumping up one that is 9 years old.

Check all your hoses for cracks, splits, or bad clamps. Check your radiator for leaks or cracked end tanks. The easiest way to do this is burp the coolant system again, place the cap on, and let the car run up to temperature (a few fan cycles) while in the driveway. If it's a leak, it should become obvious.

If the spilling coolant is coming from the overflow tank, you could have a blown head gasket, a bad radiator cap, or air pockets still in your coolant system.

How are you burping? You should be using something like the Lisle funnel. Make sure your climate control is all the way to the heat setting while burping. Squeeze hoses to push air bubbles out.

 

Run the car shortly until it starts to warm up and look at the base of the timing belt cover. If it's dripping, it's your water pump most likely causing the problem.