Hmmm..annoying. A month ago I noticed my coolant had disappeared. I filled her up and today when I checked the level the upper tank is only half full. My expansion tank is also now empty... :confused:

Here is what I have observed:
1. there is no coolant in oil
2. there is no oil in coolant
3. there is no white steam coming out of my tailpipes
4. there is very thin stream of bubles in my coolant tank when the engine is running. Bubble size is similar to bubbles in a cold beer glass ;)
5. there is slightly sweet smell in the exhaust but I think my friends cars smell the same
6. I could see no evidence of leakage on the engine - top or bottom
7. I could see no evidence of leakage on the radiador or any of its parts
8. frame, suspension etc. parts were dry too
9. my motor is little rough at all engine speeds (but cant detect it when driving >40mph). It has been this way for a long time - even before my top end rebuild a year ago. Havent been able to fix it, now suspect problems with the chargoal canister system??

So, there are all the details I figured could help in figuring this out. Please advice, where could the coolant disappear? Feel free to ask questions.

Maybe I should pull the plugs and check if any of them is too clean compared to others?

Thanks,

Toni


[Modified by ToniH, 11:48 PM 7/1/2003]

 

Well, it [I]REALLY/I] sounds like it's going out the exhaust...

 

Any other possibilities than a head gasket in your opinion?

Last year when my head gasket blew the coolant level dropped to low level (light on) in 30 minutes after a refill and there was lots of steam. Now it takes more than month to drop to half full and no steam. There was also coolant in oil that time, now nothing. This is what puzzles me. Is it possible to have such a tiny leak into combustion chamber that all is vaporized and none gets into oil and at the same time there is no steam?

There is also no power loss :confused:

Thanks.

toni

 

My co-worker has the same exact problem in his Camaro, so this morning we took it down to a friend's garage. He hooked up one of those handpump pressurizers where the radiator cap goes and pumped it up. It only took about 30 seconds to see that water was escaping from where the intake manifold gasket is. Give it a try.

 

Its possible to have a leak into combustion without seeing white smoke.
Pressure testing may narrow it down.
:cheers:

 

Thanks guys, I will try pressurizing. I just remembered that my old C3 had similar problem and when we pressurised the system we found out that the radiator neck that top hose is connected was fractured and leaked only when there was pressure present.

I keep hoping that it leaks outside as I think this all started after dealer did a complete motor flush (not positive but I think I didn't lose any coolant before that.).

Edit: update - I refilled and observed and there is no bubles at all - not even the small ones.

Toni


[Modified by ToniH, 10:34 PM 7/2/2003]

 

By all means, pressure test the cooling system, paying particular attention to the weep hole in the water pump. I would also add leak detector and check the system under pressure with a black light. There are so many areas that could leak and dry off from heat and not be visibly without the system being under pressure. Hope this helps ( check everything that has coolant in it)

 

Most exteranl leaks I've seen leave an audit trail i.e. coolant stain. Hopefully you'll get lucky and this one will be so small that it doesn't, but it sure sounds like a very small head or intake gasket leak.

Regarding the charcoal cannister, on my 85 I was able to see an improvement (i.e. prove the solenoid was not engaging) by pulling the vacuum line off the cannister and plugging it. I haven't figured out why the solenoid isn't being energized by the ECM yet, but at least I was able to prove that it was causing one of my cold start problems. As has been noted many times watch for vacuum leaks - in fact you may get "lucky" and find an intake problem causing both the coolant loss and a vacuum leak.

 

Today I tried to find a coolant stain marks ie. white residue. No luck this far.

I also talked to a local car shop about pressurizing the system and locating the leak. He said it is very difficult find such a small leak and I got the feeling that he is not very interested even to try...

Great...

 

Do you smell burnt coolant when you open the hood after driving? If it is, the radiator has a leak. It happent to my 88 for the longest time with coolant level going down very slowly in the reservoir until one day the radiator water level was down enough to show on the Instrument Panel "low coolant". This happen over a year period ~10,000 miles driven since I first smell coolant when I open the hood.

 

I did not have an obvious coolant leak either, other than the overflow was getting lower. What I found was that the water pump was dripping on the bottom end of my serpentine and the serp was dispersing the dripped coolant while the engine was running, so really the only sign that I new something was wrong was looking at the serpentine, and also the inside of the hood had traces of 'spray' from when the belt was turning.

 

Well, thanks to all. Now I finally found it. The intake gasket leaks out on the drivers side rear corner but only when hot and under pressure ie. right after I stop.

Happy to find it but not very nice job ahead :(