Good morning to all Lowyat forumer and wishing you all Happy New Year 2014, have a great and prosperous year ahead!! The mentioned car above is a Toyota Avanza (M) and currently this car still having overheating problem from time to time. I would like to share my experience here and hopefully any sifu out there can help me to identify what is wrong with my car.

The car was bought as second hand at mileage clocked @60k back in 2009 and ever since then it does not give up any problem. Car was sent to regular service at our regular mechanic workshop @every 6k mileage and no major part was replace/repair.

On one fine day while I was driving, I notice the temperature meter goes up to about 3/4 of the meter and immediately I stop at road side and check (waiting for the engine to cool down first of course) only to found out the radiator tank is empty!! I pour in water and drove to my usual mechanic shop. Upon checking the mechanic could not find any leakage and he suspect the piping has leakage. I asked him whether he could identify the leakage but he say no. He advise me to change all piping just in case and I trusted him and proceed with the changes. Total damage is RM1k.

After ~2weeks, problem occur again. This time my car was idling with air cond switch on. Suddenly there is no more cold air but instead hot air was blown via the aircond outlet, temperature was check at that time but still looking good. While approaching home, temperature meter shoot up again and upon checking radiator tank is empty...again I check the under carriage and notice some water leakage below engine compartment. Next~~send my car to the mechanic shop.

This time the mechanic still could not find the root cause but he give me 3 choices:
1. "Repair with low cost" - He suspect engine issue and say do engine top over haul as he suspect the engine
(No guarantee) piston block has worn off and thus producing excessive heat He also say
something about due to the engine problem then water sip into it and evaporate faster
This method will not guarantee that the overheating problem will stop
occurring bcz he is not sure where goes wrong.

2. "Repair with high cost" - Same explanation as 1. He suggest to do engine overhaul. He say this method will
(guarantee) guarantee the overheating problem will not occur again and the I can continue use
my car for another 5 years like that.

3. "Repair with moderate cost" - Same explanation as 1. He suggest to swap engine with those half cut shop or
(guarantee) recondition engine. This method also can guarantee that no more over
heating problem in future.

Does engine over heating will result in changing engine or overhauling it?? I am not sure whether I could trust my mechanic anymore bcz I got a "fishy" feeling from him or I am wrong?

Change your mechanic immediately.

1)Coolant used or just water ?
2)Was a pressure test of the radiator done?

I also think so haha but is it the mechanic trying to con me?


1. When the radiator tank is empty I use water to fill up. I do not know whether the mechanic use coolant or not bcz I just leave my car at his for repair ( same routine for the pass few year). The next time I know is there is over heating again and upon checking the tank is empty again so I don't know whether the mechanic did use coolant

2. I have no idea on this bro, may I know what is pressure test and how it works?


Thank you for the reply guys.

Using coolant will help identify leaks.. since it will leave stains... but water just evaporate quickly. I've identified 2 leaks easily before that was almost impossible to find with just water.


Some leaks only appear under pressure.. so a pressure test will help identify leaks in the vehicle cooling system. It's a simple job..

Hi jerry,

I would suggest you to check leakage in radiator tank.

Ic...is it hard to identify the leakage with coolant stains? bcz the mechanic say some part which is under the car engine cannot be reached so he has no idea where is the leakage, unless he "lift" the engine ><


I dont think my mechanic does this checking. In fact I am planning to bring my car to other workshop for checking or best is bringing back to Toyota SC for checking. Then once I know which part is the root cause, I will change it outside. What do you think?

Try change the radiator cap 1st and see how, i experienced the same problem, radiator tank dried and found out the cap rubber seal already full of crack hence the water evaporated out through the leaked rubber when the pressure start to build up. RM20 fix for me

This post has been edited by crayzee: Jan 2 2014, 12:48 PM

Well it's certainly easier than using plain water which leave no trace at all.. engine bay very hot, almost immediate dry up of any leaks.

I know Avanza has a lot of hoses.. but I wouldn't remove the engine just to check for leaks.

I would remove the engine to rip off and earn more money from customers.

You said you saw the water leakage. Can't you identify from where the source from? The water may leak somewhere else and dripped through outer engine components and fall off at another place.

My advice is, you yourself have to diagnose your car instead if just letting foreman to rectify unless on certain circumstances, it is totally complicated situation. Else, unfamiliar foreman will easily con you by advising you to change this and that which are not actually related to the main cause. Now days, an honest foreman are hard to find.

If you say from the engine block, I would say, it could be either your head gasket or cracked/rusted water inlet/outlet terminal or thermostat housing or damaged seals. It's easier if you can pinpoint the exact location. And yes....by adding coolant, it can help you a lot since coolant will left out residue once the water dries out...easier for you to locate the leakage.

Hope that this can help you out.

Edit : Try to find a "Workshop manual" for your engine. I think, it use the same engine as MYVI. Locate all the water passages so you'll know where to look for.

This post has been edited by gjoey: Jan 2 2014, 01:49 PM

You mean the cap where we open and pour in coolant?

Thats why he suggest me to swap engine or do engine overhaul?

Yes, I informed the mechanic about the leakage which I found earlier but I could not pin point the exact location. The mechanic did pour in water and try to see where is the leakage, he rev the car, on aircond to max and let the car stay like that for few minutes but there is no water leakage that time and water level in radiator still remain as normal. That is when I leave the car for the mechanic to further troubleshoot and gods know what he do next for checking.

Update: I just recalled that the mechanic also show me the exhaust pipe where there is water coming out. He says due to engine problem, the water from radiator leak through the engine and come out from exhaust

I am gonna check it later to see whether the mechanic did pour in coolant, if didn't can I add in Coolant myself into the radiator without flushing out the remaining water inside the radiator tank?

change mechanic. could be leaking head gasket. The water you see might not be from the radiator at all but could be from the aircond drain pipe.

Yes... but if filled with water already then not much coolant u can pour in. Anyway it will help to identify source of the leak.

Yes this cap

If the mechanic says water coming out the exhaust tip is a problem, you confirm need to change mechanic dy.

Hi Nightstalker, may I know how much would it cost to change the Head Gasket?

Thanks for the helps Unitron, by the way any specific coolant should I use in this case? Which coolant is recommended for Avanza?

Thanks for the photo Crayzee, I will check it to see whether there is any defect on it



Thanks a lot guys for the valuable information

If true that the head gasket that caused the water leak, you can do a simple test. While engine cold, open up the radiator cap and start your engine. The water in the radiator should not burst up if the head gasket is still o.k. If the water burst up, that mean your head gasket has warped or blown. The leak pressure in the combustion chamber will push out the water in the radiator.

FYI, in some cases, the crack or leak will only appear with the right amount of temperature or pressure or both. Just by running the engine idle, won't be sufficient enough.


P/S: I will not be responsible for any test you conduct ya.

TS must be kidding

1. god car can spoil?
2. kwan sooi on a japanese car?

stop trolling you conti fans

I think you should go to another workshop.