Overheated Santro: Workshop talking nonsense?!

[navpreet318]

dude get the head facing done.....

its the only way out.....a similar thing happened to my santro....i asked them not to touch the head....they didn't.....the performance went down and the fuel efficiancy went down....

then i asked them to get the head faced and got it done in front of me.....and now the performance is back to normal and the fuel efficiancy is also good enough.....


so get it done....

[djag]

Yesterday, while driving (Santro Xing 2003) to Pune on expressway I noticed engine temperature moving towards ‘H’. Immediately I stopped and found coolant boiling and being thrown out from the vent of the coolant-tank.

Car was serviced recently at Hyundai service center, so low coolant level was not expected. However, surprisingly, water in the coolant tank was ordinary water (not green) filled with rust. After the temperature became normal I found that driving upto 60 kmph without AC did not lead to heating.

I showed the car to roadside mechanic who removed the thermostat valve and topped the coolant. However, later I found that the same problem still persisted. I have given the car for trouble shooting today to the Hyundai workshop. But surprisingly, the mechanic tells me that fixing thermostat valve would solve the problem. I understand that thermostat valve plays role only in cold environment.

Since the heating problem has persisted despite removing thermostat valve the valve-malfunctioning is not the cause for over-heating. I am told that this valve costs 1000/- excluding labor charges. Hyundai advisor is sure that the problem would be solved by fitting thermostat valve (which was removed). Am I being taken for ride? Look forward for advise.

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[vivekiny2k]

Originally Posted by djag

I stopped and found coolant boiling and being thrown out from the vent of the coolant-tank.

what vent?

if you mean the overflow tube of the reservoir, most probably your radiator cap is gone. this is the one that maintains the pressure, and allows to "bleed" coolant once the pressure is above a limit. Looks like it is releasing all the pressure. Change it and it shud be fine.

About the thermostat, for proper functioning you need to have a working thermostat.

in your present condition, the coolant will start cooling the engine even before it's warmed up (engine operating temperature is much higher than environment....you do not need warming up only in cold areas), and your ECU will start screwing up with the fuel mixture.

[panky12345]

change your thermostsat & look out for proper fan working

[gbpscars]

Originally Posted by viper

Hi,

If you start the car with the radiator cap open and the water inside starts to bubble or thrown out after a few minutes then it means you have blown your gasket or warped the head or both.
Viper

hi viper,

but isn't this the way most garages or service stations change the coolant? or do you mean if the water bubbles up immediately from a cold engine, ... then the gasket is blown?

[abhilashvk]

Isn't it the problem with the radiator fan not working ,thats making the engine over heated? During emergencies, I have seen people using regular water in case the engine is heated up when the coolant levels are low.

[deep_bang]

Originally Posted by djag

I showed the car to roadside mechanic who removed the thermostat valve and topped the coolant. However, later I found that the same problem still persisted. I have given the car for trouble shooting today to the Hyundai workshop. But surprisingly, the mechanic tells me that fixing thermostat valve would solve the problem. I understand that thermostat valve plays role only in cold environment.

Hi. The thermostat you are talking about is a different one. This thermostat opens up only when the coolant is hot enough thus enabling the engine to reach warm temperature as fast as possible. This value actually blocks coolant circulation in the engine while it is cold and opens up soon after it gets warm.

However, in your case, i guess a different thermostat needs to be replaced - the one which switches on the fan when the half way mark is reached on the temp guage.

[dadu]

Thats emergency solution to an emergency situation otherwise you should always use coolant.

Originally Posted by abhilashvk

During emergencies, I have seen people using regular water in case the engine is heated up when the coolant levels are low.

[djag]

Originally Posted by djag

I showed the car to roadside mechanic who removed the thermostat valve and topped the coolant. However, later I found that the same problem still persisted. I have given the car for trouble shooting today to the Hyundai workshop. But surprisingly, the mechanic tells me that fixing thermostat valve would solve the problem. I understand that thermostat valve plays role only in cold environment.

[COLOR=black][SIZE=3][FONT=Times New Roman]Thanks folks for your advises. Its almost 2 weeks since I got overheating problem fixed by replacing thermostatic valve. However, the overheating problem has recurred while on long drive. The coolant had turned rusty brown. This time Hyundai fellow tells me that radiator is choked with rust and carbon deposit. Radiator will have to be replaced, coolant refilled, and AC will have to be serviced. This would cost approx 10000/- [/FONT][/SIZE][/COLOR]
[FONT=Times New Roman][SIZE=3]This is 4-year-old car with about 50000 km running. Car is well maintained with servicing every 3 months. Why should radiator go bad so early? Why it was not noticed earlier during regular servicing? When removing thermostatic valve had not solved the overheating problem the valve was obviously not the cause. How a professional mechanic could miss this logic?[/SIZE][/FONT]

[anupmathur]

Originally Posted by djag

The coolant had turned rusty brown. This time Hyundai fellow tells me that radiator is choked with rust and carbon deposit. Radiator will have to be replaced, coolant refilled, and AC will have to be serviced. This would cost approx 10000/-

You need another opinion! Carbon has no business being in a radiator! It is a product of combustion. Even rust in a radiator is unusual. Rust can only come from iron/steel components (engine block). How come coolant has not been inhibiting rust in your system? Did the car run for fairly extended periods with plain water?
And since the problem seems to be happening only at high speeds, there is something much more to it than what your current diagnosis shows. (Points to a leaky head gasket).

The AC service is a bit baffling. Possibly only the heat exchanger for cabin heating (being in the coolant circuit) would need cleaning. Nothing else in the cooling circuit should need to be touched and of course you should not be billed for gas/refrigerant charging. Please confirm this.

[panky12345]

10000 is too much, go for local mechanic....I got my whole radiator cleaned for R. 650/-

[djag]

Thanks Anup. Changing radiator seems to have helped. I drove 250 km yesterday on expressway with no problem. The color of coolant looks fine. Hyundai workshop actually chaged 6300/- and not 10000/- as was estimated earlier. AC servicing with gas refilling was anway due. They say that radiator cleaning by applying pressure is difficult as there are changes of rupturing the thin metal sheet. Hence radiator choking problems are not noticed during servicing.

[anupmathur]

djag, good that your problem is sorted out for now. I would recommend you keep a sharp watch on the radiator and the colour of the coolant. I do not believe that this is the end of the problem - how come there was carbon in your radiator? As I've mentioned in my earlier post, there is high possibility that your head gasket 'leaks' at higher pressures.

[SamirME01]

If you start the car with the radiator cap open and the water inside starts to bubble or thrown out ......i am faced this problem yesterday with my esteem ...what can be the reason ...i have just changed the clutch plate and the thermosata is bypassed temprorarly ...ill see the meshanic today ....want quick help

[jkdas]

Originally Posted by SamirME01

If you start the car with the radiator cap open and the water inside starts to bubble or thrown out ......i am faced this problem yesterday with my esteem ...what can be the reason ...i have just changed the clutch plate and the thermosata is bypassed temprorarly ...ill see the meshanic today ....want quick help

You knew it was bypassed. You knew it was boiling! then why?