Losing Coolant, slooooowly

[JMG]

On my 1996 Accord I am losing coolant very slooowly. No white exhaust or lost of performance. Oil is clean brown even after 3K miles. But I noticed, that in my coolant resivor I lost 1/2 quart of coolant since last oil change(11/13, 3K miles ago). Coolant was at the Max line up until it got warm here in Michigan, about 2 weeks ago, and then it went about 1" down from Max and has stayed there ever since....I had the radiator changed by Honda in June.


Any ideas?

 

[uconn1150]

Your heater core and hoses are now full since you are probably using the heater!

 

[JMG]

Really? That could be it?

 

[uconn1150]

Well, if you don't lose anymore, then yeah that's it. I've run into that here in Texas. I used the heater during a cold snap and then freaked because I was a bit down in coolant...maybe a pint...been fine since!

 

[JMG]

Probably it. Since it wasnt cold here till December, late. recently, we have been happy if its 20 degrees! But 56 degrees middle of next week, supposedly.

Thanks for your help!

 

[W.T.McGlynn]

Try some "Barr's Leak".
The "Big Three" use it on all their new cars.It's good insurance.
I have used it for many years and it works fine for me.

 

[JMG]

I parked the car over fresh snow and there was nothing but bleach white snow when I moved the car. I dont think its leaking...
I checked it again tonight, and it was about 1/2" from max... It was at Max up unitl 2 weeks ago (got really cold). I do a lot of traveling for work and check my fluids weekly.

 

[Amkeer]

The heater core thing is on the money! The only thing I would suggest here is mark the HOT water level on the resevior and check it weekly when HOT. I would also change radiator cap if you haven't done so.

Oh, make sure you use distilled water.

 

[JMG]

I will check it out. I did see some green stuff on a hose, but i thought it was from simple green when i sprayed the engine. It was a very very very little amount...

thanks!

 

[Fuelrod]

Everyone's coolant goes down Slooooly...It's called evaporation! That expansion tank is NOT airtight!

 

[doitmyself]

JMG - from your neighbor on Jolly Road - here is yet one more thing to consider.

My daughter's GM 3.4 engine started losing coolant very slowly (engine famous for manifold gasket leaks). I naturally assumed it was gasket replacement time.

Fortunately, I discovered that the WATER PUMP was going bad. GM's have a small weap hole that allows coolant leaking past the seals to "weap" out of the pump housing. A $20 dollar fix vs. several hundred for gaskets.

Look EVERYWHERE that coolant could possibly leak. We shade tree mechanics/experts sometimes over look the obvious based on forum education.

Good luck.

 

[JMG]

Thanks Neighbor on Jolly Rd. We dont live too far away from each other...

Its weird tho, cause it was full since June, but in the last two weeks its gone down about 1/2" from the Max line. I am assuming evaporation or the heater core. When the Accord needs a new timing belt, another 15K miles, they change the water pump at the same time.

It has not gone down from where it is at in at least 2 weeks. It stays the same hot or cold.

 

[Drew99GT]

Just end the speculation and have the system pressure tested. Probably will turn out to be something small like Gary Allen said; hose clamp, especially if the car now has worm clamps in place of the factory clamps. They either aren't tight all the way, or they're overtightened and dig into the rubber hose and weep slowly.

 

[ZR2RANDO]

I have bought new hoses that had plastic hangars poked through the hose close to the end- I had to cut off an inch or so (so that poke-hole would not leak..)...they could have just used tape....

 

[JMG]

I did mark it where it is at now with a marker. It hasnt changed in 2 weeks. I check it at teh gas station when I fill, so I am checking when hot. I check when cold too, and it is at the same level. I had a new rad. cap, I am assuming with the new rad. I got in June. I also checked the top of my oil cap and it doesnt have any film on it.

Thanks for all the advice!!

 

[Gary Allan]

Just to throw in my $0.02 in ..

I've had simple hose clamp issues that resulted in mysterious coolant loses. The issue is that there's a certain tightness that won't allow coolant to leak when cold (no pressure) ..nor when hot (hoses expand/swell) ..but during the transition when the coolant in the block is expanding ..yet the rad/hoses are still cold ..it pushes coolant out. This doesn't show on the ground since the pressure drops with the temp. It would show itself, perhaps, if idled from dead cold to full warm up.

A tightening of the clamps, especially after the service, usually takes care of it.

 

[JMG]

Thanks everyone for all advice!

I went to go put gas and air in the tires and I ran te car with only the vent on. I washed the car in the quater wash and left it running with the vent on. Went home popped the hood, and the coolant was at max again. I am thinking it was the heater core...

 

[Gary Allan]

Foggy windows? Wet floor? Sweet smell?

 

[JMG]

nope....
Why?

 

[darryld13]

Those are the typical symptoms of a heater core leaking coolant into the interior. Coolant absorbed by the carpeting will fog up the windows on the inside and the sweet smell is a characteristic of coolant. Your coolant level could go down each time you use the heater if the core were leaking.