it was overheating on friday night but going to normal temp when i would give it has...so i burped the system sunday its been fine since then until today on the way home it started over heating again...
i got home let it cool down for about 2 hours then went to check the radiator it was at normal level but my reservoir tank was empty

 

bump for some help

 

Do you smell coolant at any time while driving with the windows down?

You need to find out where you are losing coolant. Crawl under the car with a flashlight and look for <color of your antifreeze> stuff. Check behind the engine and underneath the timing cover where the waterpump is. Check the block drainplug. The green stuff shows up real good. Look at your hoses when the engine is hot to see if there is a pinhole leak somewhere that only sprays coolant when pressure builds or pressure test the cooling system (don't over pressurize it).

I would suspect an external coolant leak from the engine/hoses/waterpump.

If coolant is leaking into the engine/crankcase from one of the gaskets or a crack you'd likely see white/brown gunk under your oil cap

If coolant is going into the combustion chambers (through a bad headgasket or crack for instance) you will likely see white smoke and smell coolant from the exhaust.

If exhaust is leaking into the cooling system (through a bad headgasket or crack for instance) you would notice coolant is forced into the reservoir until it overflows (the reservoir will be full to the top right when you park the hot car). The coolant may be sucked back into the radiator as the car cools. Open the radiator cap when its cool and let the car warm up til the fan come on. Then look into the radiator neck (carefully to avoid leaping hot coolant) to see if there is flow (no blockage/water pump working?) and if you see bubbles coming out of the coolant (exhaust in the cooling system). To be sure you can get a block tester from NAPA ($50) to test for exhaust gasses in the radiator. If you have exhaust in the cooling system then you likely either have a blown headgasket or a crack.

If everything checks out then perhaps you have a blocked radiator (they are cheap mine was $70 from radiatorbarn.com and at my door the next day). You can get one of those infrared thermometers and check for cold spots (blockages in your radiator).

Other causes of overheating could be dragging mechanical components/friction, improper ignition timing, fuel mixture, vacuum leaks, lack of lubrication, blocked exhaust, blcoked airflow to the radiator, bad radiator fans not coming on, air cavitation in the water pump, eroded water pump impeller... Check your spark plugs, they are a good indicator of whats going on in your engine. While you have the plugs out do a compression test.

 

I have that same issue. but now my check engine light is on any other directions i can go?
93 honda civic lx i smell coolant thru AC sometimes no white smoke out of tailpipe.

 

Valid points but serious problems. It may be something simple like replacing a thermostat and gasket. Sometimes they stop working and are easily overlooked

 

Does it overheat while driving?

I would go the simple route and try the thermostat first.

Also, make sure the radiator fan is coming on.

Also pressure test the radiator, see if it will force leaks you do not see.

These are simple first steps.

 

ok..so i change the cap....and the problem got better...now it over heats...but i turn it off leave it off for 2 mins...and its back to normal.....
going to try the thermostat tomorow....

do you guys think i need to make my cooling system better...with a slim fan or a bigger radiator so it can keep up with my motor?

 

changed the cap and t-stat...ok now..

 

ok for how long.....you asked about bigger fan etc. what is your car and do you have a stock engine?

 

when i was in the fwy today the temp gauge would go up...and down....
could be air?....

99 si coupe with a b20 vtec turbo..

 

Have you bleed it?

I am wondering you don't think you have a bad gauge? or maybe is it the sensor under the dizzy for the gauge is bad?

 

make ur own thread

 

i bleed it but it does the same thing..unless im not bleeding it rite....


how do i check if the sensor is bad?

 

Ron, might know how to check it.

I am wondering if you need a higher capacity rad?

 

Does it overheat rarely and randomly?

 

it ended up being the head gasket..

 

If you let the air from the radiator, and add the coolant back in, does the car stop overheating for some time? And it does it again after you drive it harder (above 3500 RPM), sometimes even 300 miles after, or longer. If that's the case, test it for the head gasket (around 50$), because if it's leaking, the combustion gasses in the cooling sistem can sit on the sensor, or thermostat, and mess it up.

 

OOOPS, haven't seen the reply before

 

I hate to post on this thread but I'm a new member and can't start my own thread yet. I've got a similar problem. My '99 Accord 2.3 w/296,000 miles began overheating only on days over 60 degrees this past month. Since the car has been carefully maintained by me it's whole life and I'm pretty conservative, I thought I would just go ahead and replace the radiator, relay, fan switch, thermostat, hoses and the cooling fan. I bled the air from the system but it keeps doing the same thing. The only work I haven't done myself is the timing belt/water pump replacement and the last one was just done 20,000 miles ago. There's no radiator fluid on the dipstick or the ground and no steam coming out of the tailpipe. Other than the overheating, the car runs perfectly. The last time that it happened was last Friday and I did notice this time that the radiator fluid was low again (assuming that it's boiling off) as usual but when I topped off the radiator this time it didn't gurgle as if it was purging air, it instead started to come slowly out of the radiator like a small eruption. This was of course while it was running with the cap off. I'm left with only three possibilities in my mind: bad water pump, plugged block or bad head gasket but I don't think the last one is possible. Any thoughts would be greatly appreciated.

 

Was it a honda water pump that was installed?

When it overheats, while driving and idleing or both?

 

I believe it was an aftermarket water pump. It generally overheats while sitting in traffic for awhile but goes back down after the car is moving. There is coolant loss though and I'm not seeing the circulation that I think I should be seeing. Again, there are no leaks and there's no evidence of a blown head gasket.

 

With the waterpump that is one part I always go with OEM, since if it fails hard to replace. The thing is if it is the water pump I am thinking it will over heat when driving too, since the coolant is not being distributed correctly.

As for the overheating since mostly at idle, and you replaced a few things, and your fan does come on??? and it still overheats??

As for the leak, pressure test the system, might be a leak that you do not see, this will force it out.

I am thinking you might be low on coolant and then it will overheat, my car does that.

 

mine wasnt showing smoke from the tail pipe but it would smell like anti-freeze at start up...