Urgently need help, car overheating!

[Pisces69]

Doesn't seem like the water pump, because if the water pump is not working, cooling water will not flow at all - so the car will overheat even when idling.

 

I don't think its the thermostat too, because if you can smell something, then the water is really overheating.

 

My suspicion is that it is that valve in the cooling system. The function of the valve is to let the car reach normal operation temperature as fast as possible. It is closed when the car is cool (to prevent coolant flow) so that temperature can build up fast. When operating temperature is reached, the valve opens and coolant circulates around the cooling system.

 

I had two cars where the valve was stuck closed, totally preventing coolant circulation and causing the car to overheat. Your valve may have gotten stuck half-closed (never heard of it but I don't see why not possible since sludge/dirt can cause valves to be stuck in any position), thus allowing limited cooling water to flow. So its fine during idling and short gentle drives which don't heat up the engine so much - because the half-open valve will allow sufficient coolant flow to balance the temperature. But during long drives (especially high engine revs), the engine will be hotter and the partially stuck-closed valve is not able to allow full coolant circulation.

 

Anyway, best to bring it to any workshop and let them analyse....if my guess is correctly, then its as simple as removing that valve in the cooling system. The result is that the car will heat up much slower after you start the engine, but other than that everything is unchanged. Just remember not to drive the car hard (keep the revs low) till the car is fully warmed up.

 

 

I also think its e thermostat n agree what u say except e last part abt removing it without replacing it with a new piece.

 

Without it yr enging cannot get hot quickly so it wil cause e ecu to feed rich fuel mix to e engine. This means high fc n lots of carbon. Plus e engine wil lack power cos it runs too cool.

 

On a cold rainy night yr engine cannot reach e correct hot temp so u suffer high fc n loss if power.

 

Just replace that cheap part with a new piece n problem solved.

[Baddata]

TS u can try calling stockist Thian Seng see have anot..

Thanks. Not sure they have or not will try call few stockist for the thermostat and maybe get the pump too. Not sure can buy the impellers only or they come in set.

[Scandy]

This sounds like a thermostat function to me or is there any other valve other than the thermostat?

 

Actually you're right, it could be a thermostat function since cars are so wired up nowadays.

 

If I'm not mistaken, I think in some older cars like my Ford of 18-20 years ago, it was just a spring loaded valve which cracks open when the water pressure (ie. temperature) was high enough.

 

As far as I know (unless its some advanced tech engine), there is only one valve in the cooling system.

 

Basically, initial impression is that there is still some coolant circulation (otherwise it will overheat even when idling), but not sufficiently so (can't dump heat after prolonged usage).

 

 

[Scandy]

I also think its e thermostat n agree what u say except e last part abt removing it without replacing it with a new piece.

 

Without it yr enging cannot get hot quickly so it wil cause e ecu to feed rich fuel mix to e engine. This means high fc n lots of carbon. Plus e engine wil lack power cos it runs too cool.

 

On a cold rainy night yr engine cannot reach e correct hot temp so u suffer high fc n loss if power.

 

Just replace that cheap part with a new piece n problem solved.

 

I agree with you, but I don't know why the workshops always removed my malfunctioned valve and threw it away. Maybe its because my car is 9+ years now and they know I might scrap it any time.

 

Now I have to be very careful not to rev the car too much till its fully warmed up. Used to take 2-3 mins for the engine to warm up. Now it takes 10 mins or so.

 

[Baddata]

Thks Scandy, I was initially puzzled as it overheats only during long journey, when idle the temp gradually decreases. I think the fan helps a bit. It's the opposite of normal overheating.

[Pisces69]

I agree with you, but I don't know why the workshops always removed my malfunctioned valve and threw it away. Maybe its because my car is 9+ years now and they know I might scrap it any time.

 

Now I have to be very careful not to rev the car too much till its fully warmed up. Used to take 2-3 mins for the engine to warm up. Now it takes 10 mins or so.

 

 

I too had an old school mech remove e thermostat on my old overheating car long long ago.

Thats a quick easy solution in case yr radiator n water jacket is clogged with gunk n water flow is bad.

 

But bad part is yr engine cannot get to proper temp quickly n u lose power n hv high fc too.

 

The last straw was on a cold raining night when my engine was running so cold it kept jerking all e way.

I had a new thermostat installed e next day n all was back to normal.

 

Car manufacturers design e engine with that thermostat fr a good reason n not fr fun.

[Audioniche]

Radiatormhead leaking?

[Happily1986]

Actually you're right, it could be a thermostat function since cars are so wired up nowadays.

 

If I'm not mistaken, I think in some older cars like my Ford of 18-20 years ago, it was just a spring loaded valve which cracks open when the water pressure (ie. temperature) was high enough.

 

As far as I know (unless its some advanced tech engine), there is only one valve in the cooling system.

 

Basically, initial impression is that there is still some coolant circulation (otherwise it will overheat even when idling), but not sufficiently so (can't dump heat after prolonged usage).

 

i think you are referring to the pressure release/relief valve connected to the expansion tank

[Pisces69]

Actually you're right, it could be a thermostat function since cars are so wired up nowadays.

 

If I'm not mistaken, I think in some older cars like my Ford of 18-20 years ago, it was just a spring loaded valve which cracks open when the water pressure (ie. temperature) was high enough.

 

As far as I know (unless its some advanced tech engine), there is only one valve in the cooling system.

 

Basically, initial impression is that there is still some coolant circulation (otherwise it will overheat even when idling), but not sufficiently so (can't dump heat after prolonged usage).

 

 

The design of that thermostat has not changed all these years.

 

Its a spring loaded valve filled with wax. When cold e wax hardenes which cause e valve to shut off water flow to e radiator. When it heats up....e wax melts n causes e valve to open n allow e hot water fron e engine waterjacket to flow to e radiator to b cooled n cools e engine in e process.

 

It can get stuck in fully open or fully closed or somewhere in-between. It might also stick sometimes

due to rust or scale build-up which cause inttermitent problem.

 

Its a cheap part n quite easy to change so just replace it when it fails.

[Baddata]

The design of that thermostat has not changed all these years.

 

Its a spring loaded valve filled with wax. When cold e wax hardenes which cause e valve to shut off water flow to e radiator. When it heats up....e wax melts n causes e valve to open n allow e hot water fron e engine waterjacket to flow to e radiator to b cooled n cools e engine in e process.

 

It can get stuck in fully open or fully closed or somewhere in-between. It might also stick sometimes

due to rust or scale build-up which cause inttermitent problem.

 

Its a cheap part n quite easy to change so just replace it when it fails.

Thanks everyone for input . Very informative indeed. Will update the outcome after replacing the thermostat.

[Fuelsaver]

The design of that thermostat has not changed all these years.

 

Its a spring loaded valve filled with wax. When cold e wax hardenes which cause e valve to shut off water flow to e radiator. When it heats up....e wax melts n causes e valve to open n allow e hot water fron e engine waterjacket to flow to e radiator to b cooled n cools e engine in e process.

 

It can get stuck in fully open or fully closed or somewhere in-between. It might also stick sometimes

due to rust or scale build-up which cause inttermitent problem.

 

Its a cheap part n quite easy to change so just replace it when it fails.

Then what's the diff btw normal n sports thermostat?

[Fuelsaver]

I too had an old school mech remove e thermostat on my old overheating car long long ago.

Thats a quick easy solution in case yr radiator n water jacket is clogged with gunk n water flow is bad.

 

But bad part is yr engine cannot get to proper temp quickly n u lose power n hv high fc too.

 

The last straw was on a cold raining night when my engine was running so cold it kept jerking all e way.

I had a new thermostat installed e next day n all was back to normal.

 

Car manufacturers design e engine with that thermostat fr a good reason n not fr fun.

Same here, last time my proton ride oso had it removed for good but did not feel any issue though.

[Pisces69]

Then what's the diff btw normal n sports thermostat?

 

 

No idea at all.

[Pisces69]

Same here, last time my proton ride oso had it removed for good but did not feel any issue though.

 

 

So i guess that method works sometimes but not all e time.

[Yeobh]

The fastest way to check for in-operational thermostate, slow or no flow of coolant in water jacket/pipe etc and hot spot is to use a non-contact thermometer.

For thermostat operation statute, check the temp of the bypass hose and radiator top hose. Initial engine running, bypass hose temp should be much hotter than top hose. When the thermostat comes into operation due to high operating coolant temp the bypass hose temp will drop and the top hose will show high temp .This means the thermostat is in good working conditions. If the top how still remains at slightly above ambient temp - the thermostat is not working and therefore do not allow coolant to flow into the top hose.

By taking temp of the engine blocks, hose and pipes, the mech can do a temp audit and determine the slow flow locations which maybe due to heavy rust deposit , hose inner layer collapse etc.

[Xtrah]

Probably thermostat problem. I had the same problem and engine temp goes as high as 110 degree celcius show on my diagnostic dashboard. Then when I switch off the enigne, I can hear the fan trying to cool down the engine and stopped once it cool down. Had mine replace and it resolved the problem. Not expensive. Try touching the 2 hoses connected to the engine. Both should feel hot. If one cold one hot, then is probably thermostat problem.

[Gendut]

Then what's the diff btw normal n sports thermostat?

 

Sports is set higher. Its got something to do with higher power output from the Otto cycle.

 

I may be wrong though