Its been long that i have come to nairaland with a problem.

Finally, one is here but am lost on where to start.

The problem started 2months ago when i suddenly noticed coolant has disappeared from reserve tank and gone down in the radiator. I filled back both with about 4litres of water. 3 days later i checked again and found the same thing. Note, since i got the car, water level has never changed. My mechanic didnt notice any leakage. The temp guage always remains at its usual position just shy of the middle.

I had to check coolant every other day but discovered the problem happens erratically. 3days ago, i came back to my house from a 3km distance, the water in the reserve tank was boiling. Now it happens every small movement i make. Yesterday, it was boiling, today it became worst cos i refilled 3times.

I still believe the coolant is factory fitted since its still pink in colour. Note that the car was bought brand new in Nigeria and had a rollover accident (sumersoult) but engine wasnt affected. Replacing the original Toyota long life coolant should be after 160,000km which is now at 135,000km. Thermostat is still fitted.

Questions.
Can the coolant itself be the cause? In an order, which item should i start checking among these; thermostat, coolant, cooling fan, water pump. Where will the possible location of my thermostat be? I have ruled out leakage.

I will only go back to the mechanic when i am positive on the cause, for now its DIY. I also donot have a thermometer to carry out thermostat test.

Also check the radiator cap.

Are u sure your fan is not sucking air instead of blowing. I am not an expert or engineer but I experienced this kind of thing years ago in my golf.

olumidazz: Are u sure your fan is not sucking air instead of blowing. I am not an expert or engineer but I experienced this kind of thing years ago in my golf.

Fans on cars are designed to suck air not blow. As the car travels forward and air blows on the radiator the fan also assist in sucking more air. If the fan blows air it will be blowing against the direction of air flow which will be pointless. Thats why a piece of paper or polythene gets stuck on the radiator and hardly falls.

The type of fan on this car, i dont know how it works. It is belt driven, but sometimes speeds up and down. When engine is not on, the fan is free and can be rotated by hand. I wonder at its mechanism.

What's the make and model?
The beginning of your account seemed to point towards the radiator cap. Pressure loss from it would lead to coolant shortage and when not treated early, progress to overheating.
If you say the fan is belt driven, then what you have is a Viscous fan system.
The fan has a clutch containing a viscous fluid which viscosity increases with temperature and thus, it rotate at the engine speed.
The lower the temp. the lesser the fan speed. A defective clutch can cause overheating.

Mc oldsoja: What's the make and model?
The beginning of your account seemed to point towards the radiator cap. Pressure loss from it would lead to coolant shortage and when not treated early, progress to overheating.
If you say the fan is belt driven, then what you have is a Viscous fan system.
The fan has a clutch containing a viscous fluid which viscosity increases with temperature and thus, it rotate at the engine speed.
The lower the temp. the lesser the fan speed. A defective clutch can cause overheating.

Its a 2006 Toyota Prado with a 2.7vvt I4 engine.

The water spill is at the reserve tank not at the cap.

See pics of engine on my previous thread.

https://www.nairaland.com/1071557/how-use-auxillary-gear-toyota

@adanni u won't believe this is what my rewire did for me some years ago and I discovered the car was overheating severely until I sold it off. I have always been under the impression that fans must blow air instead of suck, I just checked the direction of flow of my car now and discovered it is sucking air as against blowing air. Thanks for this piece of information.

Change your radiator cap.


Car-Doctor.

car-doctor:
Change your radiator cap.


Car-Doctor.

Oga any chance of Τђε op's car thermostat being faulty?

car-doctor:
Change your radiator cap.


Car-Doctor.

I think its worth trying. I shall find it tomorrow and see what changes may effect. My mechanic can lend me one for trial purpose from his workshop.

I had had such a problem before, it is similar.

shoot@sight:
Oga any chance of Τђε op's car thermostat being faulty?

I thought so too. The idea of starting with the cap is good.

Once again, Nairaland has been instrumental to solving my car problems. I have successfully avoided the usual trial and error which most times result in damage of parts that were never faulty in the first place.

car-doctor:
Change your radiator cap.


Car-Doctor.

Mc oldsoja: What's the make and model?
The beginning of your account seemed to point towards the radiator cap. Pressure loss from it would lead to coolant shortage and when not treated early, progress to overheating.
If you say the fan is belt driven, then what you have is a Viscous fan system.
The fan has a clutch containing a viscous fluid which viscosity increases with temperature and thus, it rotate at the engine speed.
The lower the temp. the lesser the fan speed. A defective clutch can cause overheating.

I followed ur tip and 'hit the nail on the head' without much stress. A new cap was just N300 which i immediately noticed the problem. Something was missing on the cap i was using and i could see the rough edge where a missing part of the radiator cap broke off. The pic is shown below.

For now, i have not yet experienced a shortage.

as simple as a radiator cap. thanks to your inquisitive mind and thanks to naira land....

@adanny01....thank goodness the overheating issue is resolved. I just noticed that the a reduction in my radiator water as well. Its a 50-50 mixture of water and coolant, i have been using the car for over 4months now without any complain. I also observed the radiator isn't leaking. Pls could it be that i need to change the radiator cap to resolve loss of content? My radiator cap has 88kpa written as the pressure spec. Please advise appropriately....

chemvic: @adanny01....thank goodness the overheating issue is resolved. I just noticed that the a reduction in my radiator water as well. Its a 50-50 mixture of water and coolant, i have been using the car for over 4months now without any complain. I also observed the radiator isn't leaking. Pls could it be that i need to change the radiator cap to resolve loss of content? My radiator cap has 88kpa written as the pressure spec. Please advise appropriately....

Diagnosing water shortage and overheating is a very tricky thing to do. Even a mechanic may not be exact with the problem. You, the user, is in the best position to diagnose the problem but you have to know the exact behavior.

Let me itemize some checks for you to do.
1. Does the car temperature go beyond normal?
2. Does the overheating show on the temperature gauge?
3. When it overheats, where does water escape from (you have to find that when the car actually overheats)?
4. Do you still have the thermostat installed?
5. Does your cooling fan work?
6. Check your engine oil dip stick for traces of water.
7. How long a drive do you take before water shorts, that is, is the shortage rapid in a short period or slow over a long period?
8. what quantity of water do you add, lets say every 2days?

There are still a lot of questions. You have to observe and describe every tiny detail. Water will only be short in these areas, radiator cap, pipes, head gasket, water pump, radiator and lastly the reserve tank overflow pipe.
When doing trial and error, start with the cheapest solution like the radiator cap which in my case was N300. I bought a used (Belgium) not the new substandard ones around.

My Mazda tribute overheats and discharges or drains water through the reservoir discharge hose. This happens just 10 mins after the car is started. I noticed this when I had a leaking radiator and asked an 'Agbede' to fix it.
I don't want to call a mechanic who will compound my problem by asking to change all that are not necessary.
Car gurus in the house what do I do?
Please treat as urgent.

floridam: My Mazda tribute overheats and discharges or drains water through the reservoir discharge hose. This happens just 10 mins after the car is started. I noticed this when I had a leaking radiator and asked an 'Agbede' to fix it.
I don't want to call a mechanic who will compound my problem by asking to change all that are not necessary.
Car gurus in the house what do I do?
Please treat as urgent.

Change your radiator cap. Make sure you are replacing with the original replacement part and the exact type. They old and the new must be physically the same.

It is advisable to buy belgium (used) cap if you are not sure the new one is original. There are too many fake new caps in the market.