Zen throwing off coolant

Tarun · 18th July 2009, 18:31

Guys,

First time in the my history of driving a 99 Zen with 146000 kms tracked, I faced an issue while taking her out.

The problem:

I drove for about 14 kms with full ac. Park the car and move out to buy some things while my wife is in the car with AC on. When I return after 5-6 minutes, i see all coolant spread on the road beneath the car. Wife had switched off the car as some passerby indicated the coolant spread. I checked the temperature gauge and it was HIGH. Waited for about 10 minutes and arranged for some water. Opened the radiator, it was fuming and slowly pored water inside. Also the side plastic tank which stores the coolant / water was boiling. I drove back slowly as soon as the temp gaurge was back to normal and had to stop once in 14 kms of driving with no ac and bumper to bumper traffic.

Now, what is the root cause of this?

The radiator?
AC?
Others??

Pls. advise.

Tarun

gpa · 18th July 2009, 19:19

Tarun,

It looks like your car's cooling system was not able to handle the extra load thrown at it by the a/c which is why, it started to overheat when you left it idling with the a/c switched on.

Do not pour cold water or coolant directly into the radiator when you find the coolant bubbling as it will lead to thermal shock and a blown head gasket. Wait for atleast 30 to 45 minutes for the system to cool after you open the radiator cap and then pour in the coolant/water.

Ask your sevice station to do a thorough check of the car's cooling system as you have clocked some serious miles on it. It could just be a block in the system that led to this one of incidednt that you mentioned.

Also make a mention for them to check the head gasket to see if its blown.

Cheers,
gpa

Tarun · 18th July 2009, 21:53

gpa, what could be failure in the cooling system? Do you have any idea how the cooling system works and what could be the potential failure points? Does it call for radiator change? or is it the spring which basically is there for the prevention of freezing the coolant in chilly conditions.
From some fellow maruti owners, I have heard the the spring does not operate after some period and they opt for removing the spring understanding that it is of no good use.
For some the radiator cleaning, wherein the option is to remove the internal springs and get it thoroughly cleaned. Though not sure if any of these is true.

Pardon me for asking so many questions.

The service owners usually talk of replacing this or that without proper diagnosis of the problem. So I basically wanted to avoid them taking me for a ride.

Thanks,
Tarun

gpa · 18th July 2009, 22:13

The functioning of a cooling system in a car is rather simple. The most important function of the radiator is cool down the engine and getting rid off the heat by circulating water through the pipes (also referred to as jackets) located around the core operating parts of the engine.

I think what you are referring to is the car radiator thermostat. It is a temperature operated flow control valve specially designed to control the engine temperature. A car radiator thermostat consists of a seamless bellow as the sensing element. It works on the principle of partial vapour charge and could possibly be malfunctioning in your case considering the number of clicks on the odo.

Take your car to a service station and make mention to have the termostat valve checked.

Sometimes, scaling could have taken place inside the cooling jackets of the engine and all you would need is a radiator flush to set things right.

Hope this helps

Do keep us updated on what happens.

Cheers,
gpa

rajivanoj · 20th July 2009, 21:20

check your radiator fan, whether it is working or not?
check with just running engine and look for gauge and fan, see whether the fan starts when the temperature reaches abnormal.

look for fan rotation, it shoud pull air from outside and throw inside. I had an bad experience with my esteem, when the electrician made the fan to rotate opposite side, and without knowing, i drove for about 25 kms and it started all boiling symptoms etc, and atlast the head gasket blown

vivekiny2k · 20th July 2009, 23:38

the radiator cap is responsible for slowly releasing the coolant into the reservoir when under pressure. when cold, it pulls it back in system.

if the coolant is boiling out within minutes of starting, either it's too much of heat (less likely), or the cap valve has failed. change the radiator cap and see.

you can do it yourself. just twist, open, replace.

18th July 2009, 18:31	#1
Tarun BHPian Join Date: Apr 2004 Location: New Delhi Posts: 158 Thanked: 17 Times	Zen throwing off coolant Guys, First time in the my history of driving a 99 Zen with 146000 kms tracked, I faced an issue while taking her out. The problem: I drove for about 14 kms with full ac. Park the car and move out to buy some things while my wife is in the car with AC on. When I return after 5-6 minutes, i see all coolant spread on the road beneath the car. Wife had switched off the car as some passerby indicated the coolant spread. I checked the temperature gauge and it was HIGH. Waited for about 10 minutes and arranged for some water. Opened the radiator, it was fuming and slowly pored water inside. Also the side plastic tank which stores the coolant / water was boiling. I drove back slowly as soon as the temp gaurge was back to normal and had to stop once in 14 kms of driving with no ac and bumper to bumper traffic. Now, what is the root cause of this? The radiator? AC? Others?? Pls. advise. Tarun
	() Thanks

18th July 2009, 19:19	#2
gpa Senior - BHPian Join Date: Aug 2008 Location: Bangalore Posts: 1,795 Thanked: 363 Times	Tarun, It looks like your car's cooling system was not able to handle the extra load thrown at it by the a/c which is why, it started to overheat when you left it idling with the a/c switched on. Do not pour cold water or coolant directly into the radiator when you find the coolant bubbling as it will lead to thermal shock and a blown head gasket. Wait for atleast 30 to 45 minutes for the system to cool after you open the radiator cap and then pour in the coolant/water. Ask your sevice station to do a thorough check of the car's cooling system as you have clocked some serious miles on it. It could just be a block in the system that led to this one of incidednt that you mentioned. Also make a mention for them to check the head gasket to see if its blown. Cheers, gpa
	() Thanks

18th July 2009, 21:53	#3
Tarun BHPian Join Date: Apr 2004 Location: New Delhi Posts: 158 Thanked: 17 Times	gpa, what could be failure in the cooling system? Do you have any idea how the cooling system works and what could be the potential failure points? Does it call for radiator change? or is it the spring which basically is there for the prevention of freezing the coolant in chilly conditions. From some fellow maruti owners, I have heard the the spring does not operate after some period and they opt for removing the spring understanding that it is of no good use. For some the radiator cleaning, wherein the option is to remove the internal springs and get it thoroughly cleaned. Though not sure if any of these is true. Pardon me for asking so many questions. The service owners usually talk of replacing this or that without proper diagnosis of the problem. So I basically wanted to avoid them taking me for a ride. Thanks, Tarun
	() Thanks

18th July 2009, 22:13	#4
gpa Senior - BHPian Join Date: Aug 2008 Location: Bangalore Posts: 1,795 Thanked: 363 Times	The functioning of a cooling system in a car is rather simple. The most important function of the radiator is cool down the engine and getting rid off the heat by circulating water through the pipes (also referred to as jackets) located around the core operating parts of the engine. I think what you are referring to is the car radiator thermostat. It is a temperature operated flow control valve specially designed to control the engine temperature. A car radiator thermostat consists of a seamless bellow as the sensing element. It works on the principle of partial vapour charge and could possibly be malfunctioning in your case considering the number of clicks on the odo. Take your car to a service station and make mention to have the termostat valve checked. Sometimes, scaling could have taken place inside the cooling jackets of the engine and all you would need is a radiator flush to set things right. Hope this helps Do keep us updated on what happens. Cheers, gpa
	() Thanks

20th July 2009, 21:20	#5
rajivanoj BANNED Join Date: Mar 2007 Location: Coimbatore Posts: 398 Thanked: 52 Times View My Garage	check your radiator fan, whether it is working or not? check with just running engine and look for gauge and fan, see whether the fan starts when the temperature reaches abnormal. look for fan rotation, it shoud pull air from outside and throw inside. I had an bad experience with my esteem, when the electrician made the fan to rotate opposite side, and without knowing, i drove for about 25 kms and it started all boiling symptoms etc, and atlast the head gasket blown
	() Thanks

20th July 2009, 23:38	#6
vivekiny2k Senior - BHPian Join Date: Feb 2005 Location: cincinnati, jabalpur,chennai Posts: 1,264 Thanked: 212 Times View My Garage	the radiator cap is responsible for slowly releasing the coolant into the reservoir when under pressure. when cold, it pulls it back in system. if the coolant is boiling out within minutes of starting, either it's too much of heat (less likely), or the cap valve has failed. change the radiator cap and see. you can do it yourself. just twist, open, replace.
	() Thanks