[khoj]

Hello again Gansan,

What the little interlude below means is that in every day life checking the plastic reservoir is enough, what is also true is that sometimes life serves you a low hand and things do not work out the way they are supposed to.

So if conditions arise that you are stuck and need to open the hood check the radiator irrespective of what the temp. gauge says. Only thing is do not touch a hot radiator cap and open it once it has cooled down. Even then do not lean over the radiator but open the cap from an arm's length, a shower of steam in the face is not at all desirable.

[Gansan]

Originally Posted by anupmathur

LOL, I sympathize with your concern!
The temperature gauge is useful only as long as there is fluid in the radiator!
With fluid lost and the sensor hanging in air, there is no way the poor thing can tell you the temperature of the fluid (which is not there)!

That is why in other critical machinery setups there are TWO gauges that work in 'tandem' - one is a flow sensor to confirm that fluid flow is actually taking place and the other is the temperature sensor that tells you the temperature of the fluid! One or the other is not good enough - you need both to know the full story.

Originally Posted by khoj

Hello again Gansan,

What the little interlude below means is that in every day life checking the plastic reservoir is enough, what is also true is that sometimes life serves you a low hand and things do not work out the way they are supposed to.

So if conditions arise that you are stuck and need to open the hood check the radiator irrespective of what the temp. gauge says. Only thing is do not touch a hot radiator cap and open it once it has cooled down. Even then do not lean over the radiator but open the cap from an arm's length, a shower of steam in the face is not at all desirable.

OK, I follow you guys so far, but what I can't understand is if the radiator is empty, surely all the coolant in the plastic reservoir should be gone too?

[Thad E Ginathom]

Originally Posted by anupmathur

... The temperature gauge is useful only as long as there is fluid in the radiator! ...

By which point, the horrible grind as the engine seizes up would be the thing to tell you that something is wrong!

[Raccoon]

Originally Posted by khoj

well tap water will have some scaling effect with prolonged usage but then that is the reason we have the glycol with all of the additives including one with antiscaling properties. Further the impurities would have to be present in humongous quantity to really do some damage and such water sample would give it away visually by appearing cloudy, reddish, greenish, yellowish etc etc and no one would be using that correct. I have a 1996 Zen with 200+K on the meter. this car has been brought up on a pure diet of tap water available with various MASS in Delhi and others spread as far as Goa in the South to Pathankot in the North, Mumbai & Pune in the West to Lucknow in the East. In the last 13 years everything in this car has moved around, except the engine, gear box, the cooling system including the temperature gauge needle. Well the TG needle does move but it comes to a rest at almost the same point on the gauge slightly below the mid mark. trust the Zen, the mutes do not lie.

As for the defrost water well it is indeed water, the odour is because in the drain pan sits the muck that gets accumulated along with other things that can find their way into the pan. Besides even I am not given to quench my thirst with it but for use in the car well if I can filter it get rid of the muck etc sure.

As for the distilled water manufacturer you have covered that very well and regarding the costs incurred as long as his customer that is your battery wallah knows about the extra magic he has recovered his costs and more.

Well, even a steam iron can end up with scaling on the insides. It may be possible that in real life, the scaling does not happen in the car cooling system due to the antifreeze, etc., but personally, I'd only feel safe to use distilled water, just to err on the side of caution, if nothing else. Logic being, tap water is far more questionable than a good brand of distilled water. And doing only incurs a small extra cost.

About the defrost water, I doubt that it is ONLY water, because I have personally seen to it that the tray is really clean before beginning to defrost. And it still has a disagreeable odor.

Originally Posted by Gansan

OK, I follow you guys so far, but what I can't understand is if the radiator is empty, surely all the coolant in the plastic reservoir should be gone too?

Nopes, may not happen that way. If the system looses its air-tightness, the fluid in the reservoir will not shift place.

[sudharma]

Originally Posted by anupmathur

That is why in other critical machinery setups there are TWO gauges that work in 'tandem' - one is a flow sensor to confirm that fluid flow is actually taking place and the other is the temperature sensor that tells you the temperature of the fluid! One or the other is not good enough - you need both to know the full story.

You are 100% right. I have worked on these system in the last 35 years. There are more than one Temperature Indicators and a flowsensors on the cooling system. The flow sensors are simple paddles in the coolant path which operates a microswitch to gives an alarm when there is no coolant flow in the respective coolant paths.

I always wonder why not monitor the engine block temperature than monitoring the coolant? After all the job of the coolant is to keep the engine temperature under control!.

Can some one clarify?

As for the loss of coolant and the temperature reading:-
As the coolant level starts going down in the radiator, there is not enough coolant in the radiator to effectively cool the engine and the temperature starts rising. The temperature will keep rising till there is no more coolant circulating, and then the temperature will start going down fast.
This observation is from my own experience when I had a minor accident and one of the radiator cell was cut and started loosing coolant. I had to reach the nearest Radiator Repair shop which was about 5Km away. When the temperature start climbing, stopped the vehicle kept the engine idling and kept pouring water into the radiator till the engine temperature became normal. Had to repeat this process a few times till I reached the repair shop.

[Gansan]

Then what is the solution, short of opening the radiator every now and then? Apart from the under bonnet checks once a week which is done on a cold engine, may be we should check the coolant level when the engine is hot once in a while, immediately upon returning home from work. I have observed that the coolant level is about 0.5 inch above the "max" mark when I do this, and drops down to match it the next morning when the engine is cold.

May be if the level does not change like this, it can be an early warning sign?

[vivekiny2k]

in this country 6 months of winter we wait for first 10 minutes till the coolant gets hot before we get hot air, we monitor the functioning effectively everyday . Even otherwise I keep an eye on the temp gauge and fuel gauge almost all the time.

[anupmathur]

Originally Posted by Gansan

....
May be if the level does not change like this, it can be an early warning sign?

Aye, it would be!
I've mentioned it here:

Originally Posted by anupmathur

.... If the radiator or its cap have the slightest leakage a vacuum cannot form. The fluid level in the radiator will keep dropping and that in the reservoir will stay nearly constant.
.....

[Gansan]

Originally Posted by anupmathur

Aye, it would be!

Thanks! Are you from Navy/Merchant Navy background, sir?

[sudharma]

Originally Posted by Gansan

Thanks! Are you from Navy/Merchant Navy background, sir?

If the question is directed towards me, then you are not very far off. I worked for an Oil Company in the production/Maintenance department.

If not just ignore this post.

[khoj]

Originally Posted by Raccoon

About the defrost water, I doubt that it is ONLY water, because I have personally seen to it that the tray is really clean before beginning to defrost. And it still has a disagreeable odor.

The car does not have a nose

Jokes apart, I am not insisting that tap water be used but merely sharing my experience from everyday life.
Coming back to the water in the tray. water has tremendous absorption properties and even though the tray is clean the water as it trickles down and even when it is simply lying in the tray keeps on absorbing the various aromas and smells and it is this cocktail which gives the disagreeable odour.

[sgiitk]

Originally Posted by nandans2005

khoj,

Its a normal practice that while topping up, both the radiator & the coolant container are topped up....i really dont understand why this was being done though only the container needs to be topped,

If you top up the reservoir (assuming the reservoir was empty) in the next cycle the fluid automatically gets sucked into the radiator. So keeping the reservior topped up is what is needed, unless the radiator is quite empty.

Originally Posted by sudharma

What I actually meant was "100% Glycol" and not coolant as reply to some one's question "why not use 100% coolant". Anything you use to cool some thing is a coolant.

Does not serve any purpose. Diethylene Glycol alone is not the idea fluid, since you need the anti corrosives etc. With 100% coolant you are overdoing the lube and anti-corrosion bit (since even 20% is Ok). Also, the anti-freeze part is best at 63% where the freezing point is the lowest. So I see no reason for 100% coolant. It is more viscous so the cooling capacity will be compromised.

[Thad E Ginathom]

Again, although I agree with your point, you are confusing the issue with your use of the word coolant.

The system (assumng it isn't empty) always contains 100% coolant!

[Raccoon]

Originally Posted by khoj

The car does not have a nose

Jokes apart, I am not insisting that tap water be used but merely sharing my experience from everyday life.
Coming back to the water in the tray. water has tremendous absorption properties and even though the tray is clean the water as it trickles down and even when it is simply lying in the tray keeps on absorbing the various aromas and smells and it is this cocktail which gives the disagreeable odour.

Well, you could have a point, but try taking some of that snow/ice and let it melt outside the fridge in a clean and covered container. I kinda remember doing this pretty long ago, and I guess the water still had a very different taste and smell. That suggests that its more (or less?) than just water. Anyways, we have a frost free fridge now, so neither can I do this again to confirm, nor is using defrost water an option for me at least and nor is this the best way to prove its composition.

[khoj]

Hi Racoon,

Well I agree the defrost water is definitely not an option for me either. Imagine trying to push an overheated car home to the fridge or coming home to bring back the defrost water to the car.

Sorry, could not resist that.

But seriously, I agree with you on not using the defrost water.