Misterious coolant leak

[ZaintS]

Hi! Once again I come to you hoping you can help me with my problem. Last time I had some shifting problems, but it's ok now.

I have 1997 1.6L (98ci) esteem/baleno wagon. G16B 16V

For some time I have had a coolant leak. Had a lot of ideas, what could cause this and therefore have changed and checked many things.

Changed:
1. Radiator
2. Head gasket
3. Thermostat

Checked:
1. Coolant reservoir tank not broken. Wrapped newspaper around it and in my opinion if there could have been a leak the ink should have been messed up, but it wasn't
2. Water pump completely dry, not a single sign on it for any leaks.
3. Interior heater fine (no coolant inside the car, carpets dry)
4. Piping and connections all ok, checked everything, replaced one connecting clamp that seemed to be the problem, but still no help.
5. Never any puddles under car not even once it stayed on a same spot for half a week.
6. No coolant in oil or vice versa

Never have overheated...
It seems that coolant is disappearing when I'm driving. Haven't noticed any disappearance during the time car is parked. It keeps disappearing randomly, sometimes more, sometimes less, but couple of weeks ago 750ml (45ci) of coolant disappeared in one week. It's quite a lot I think.

So I ask for any ideas and of course help to solve what could cause the leak!

Thanks in advance! ZaintS

[RebelPC`]

Heater cores sit in a box that is plumbed outside the vehicle now, so you wouldnt see any coolant inside the vehicle even if it was leaking......Can you smell coolant or does the windshield fog up when you turn on the defroster initially? My guess would be a tiny leak in the heater core is probably where your coolant is going. Also consider replacing the rad cap....when they lose their seal coolant evaporates.

[ZaintS]

thanks for your answer!!!

I forgot to write this, but I also did the "start-up the engine and turn the blower on" test and no it doesn't smell or fog up the windshield.

I actually thought about radiator cap myself. Today I even went to brakersyard to get another one, but they didn't have one. So tomorrow I'll go to dealer's and get myself a brand new one, hoping this would solve my problem.

So because you also suggest it this really could be the reason my car is "sweating" Thanks mate!

[Isuzuzuki man]

I've had leaks in a hose connection on both my 02 Esteems, same location, the spring clamp or something there is not quite tight enough, which results in a very small leak, but not the quantity you speak of.

[jim_naisium]

After a long drive turn off the engine and remove the air tube from the throttle body and open the throttle butterfly and see if you can smell antifreeze inside the intake manifold.

If you can there is a rubber hose that connects to the back side of the throttle body and goes through a miniature choke (then goes back to the engine) that opens up as the engine gets warmer to let a little more air through the idle circuit, if you can smell antifreeze inside the intake manifold this may have sprung an internal leak and the engine is sucking the antifreeze into the cylinders.

[ZaintS]

ok... so I bought a new radiator cap and in two days I lost about 1L (60ci) of coolant!!! Leaking is becoming somewhat bigger all the time, but I still can't figure out the reason... also checked the spark plugs and they are all in the best shape which means coolant doesn't get into the combustion chamber.

Weird thing is that nothing seems to help... I'm completely running out of ideas and hope...

If anyone has any more ideas, please share!!!

[jim_naisium]

Well, due to our current laws of physics it can't simply be disappearing which means that it is going somewhere.

1 - Engine is sucking it into the cylinders, this may be such a small amount over time that it is actually cleaning your spark plugs for you, I would still smell the inside of the intake manifold just to rule that out as being the problem.

2 - It is externally leaking from the engine, this may also be such a small amount that you can't see it, it just sprays into the air while you are driving it although if this were the case you should have some kind of anti-freeze residue clinging to the firewall, some part of the engine or the underside of the car.

Try putting some leak detector dye into your antifreeze then drive it for a while then use a black light on it (wait until it gets dark or put it in a very dark garage) and see if there are any tiny leaks showing up anywhere.

3 - Someone is messing with you and draining out just enough to drive you crazy but not cause engine damage, you have any friends that like pulling little pranks on each other?

[sd_read]

I just went through this a few months ago and I agree with Isuzuzuki man.

I had very similar symptoms as you, never overheated and was somewhat erratic.

I checked everything you did. Could only figure it was burning but the plugs showed no signs.

Same as you, I would sometimes loose a lot at once.

I noticed some coolant laying on the lower rad hose but too little to be of concern.

Out of desperation (better than pulling the head) I loosened all clamps twisted the hose so it was loose and then re tightened the clamps to "reseat" everything.

Now, many weeks later, my coolant is staying level.

I can only assume that under certain conditions/pressures the coolant would suddenly leak out while on the highway. That would also explain why no signs of burning or puddles in the driveway?

Steve

[Isuzuzuki man]

Doesn't sound like its leaking into the cylinders, but try this, drive the car, then shut it off, when it cools off completely, ~10 hrs or overnight, pull the plugs and crank it over, if there is coolant in there it will splatter out.

[Ahmed Rashid]

Check the head thoroughly,there might be a hair line crack due to over tightening or uneven tightening sequence.Also check the flushing plugs.