"overheating" car

If the fan is only coming on at a higher temp and then the engine cools down then it's a sticky thermostat most likely, if it was water pump or blocked pipes the car would be continuously running hotter.
 
OK, some testing going home. 100km/h all is fine, needle in middle. 120km/h shoots up to top. Drops back quickly when on 100km/h.

Reservoir pipes and inlet pipe from engineer to radiator hot to touch, top right of radiator hot to touch (that's near inlet), hotness fades to lukewarm on left, middle not even luke warm, bottom half cold, outlet pipe cold.
 
supersunbird said:
OK, some testing going home. 100km/h all is fine, needle in middle. 120km/h shoots up to top. Drops back quickly when on 100km/h.

Reservoir pipes and inlet pipe from engineer to radiator hot to touch, top right of radiator hot to touch (that's near inlet), hotness fades to lukewarm on left, middle not even luke warm, bottom half cold, outlet pipe cold.
Click to expand...

Yea I bet it's the thermostat, while the water is out I'd have the radiator flushed and cleaned. then you should be good to go
 
the thermostat is probably stuck open a little bit. higher speed means higher revs so engine runs hotter. unless the radiator is almost totally clogged...
 
supersunbird said:
OK, some testing going home. 100km/h all is fine, needle in middle. 120km/h shoots up to top. Drops back quickly when on 100km/h.

Reservoir pipes and inlet pipe from engineer to radiator hot to touch, top right of radiator hot to touch (that's near inlet), hotness fades to lukewarm on left, middle not even luke warm, bottom half cold, outlet pipe cold.
Click to expand...

Thermostat then.

This is how the thermostat works. It opens under pressure, when the engine gets hot the pressure from the water pushes the thermostat open from the radiator's side. Forcing in colder water and the hot water then gets pushed out to the inlet of the radiator.

If the inlet is hot but the outlet of the radiator is cold that means the water from the engine is not making it's way through the radiator as the temp should be even. The thermostat you will find at the outlet pipe from the radiator where the pipe goes into the engine. Take it out and replace it. If you still have a problem then check the water pump.
 
Pitbull said:
This is how the thermostat works. It opens under pressure, when the engine gets hot the pressure from the water pushes the thermostat open from the radiator's side.
Click to expand...

?

[video=youtube;T8cGKdICJmc]https://www.youtube.com/watch?v=T8cGKdICJmc[/video]

The thing where pressure comes into play is cooling systems are pressurised in order to prevent the water boiling at a lower pressure, the higher the pressure the higher the boiling point. The pressure does not activate the thermostat, if it was activated by pressure it would have been called something like a 'presustat' or a 'presure valve' etc and not a thermostat which implies it's activated by temperature. As shown in the video one can see it's heat activated at atmospheric pressure, there's nothing pushing on it.
 
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ponder said:
?

[video=youtube;T8cGKdICJmc]https://www.youtube.com/watch?v=T8cGKdICJmc[/video]

The thing where pressure comes into play is cooling systems are pressurised in order to prevent the water boiling at a lower pressure, the higher the pressure the higher the boiling point. The pressure does not activate the thermostat, if it was activated by pressure it would have been called something a 'presustat' or a 'presure valve' etc and not a thermostat which implies it's activated by temperature. As shown in the video one can see it's heat activated at atmospheric pressure, there's nothing pushing on it.
Click to expand...

I have never seen one work in real life. I have only seen the actual device and it's a spring loaded valve. I just made my own conclusions. However the simptoms do indicate it's a faulty thermostat.
 
My symptoms on a vw bus the other day was the following:
Accelerate, and temp climb.
Cruise, decelerate and idle, temp come down.
Turned out to be a small hole in top gasket between cylinder and water.
Also, my oil looked very black, so i took it for service. After service, and some driving, the new oil seemed very thin. Continued with daily driving, when the hole expanded and blew smoke from exhaust. That's when we found the gasket problem.
 
Check your oil on dipstick and under oil filler cap...micro crack between water and oil jacket will also do this...
 
I have the same problem on a similar car.

Turned out to be dirty water in the radiator.

If the water is a muddy red, its time for a radiator flush.

In the mean time, when the car overheats, stop at the garage and get one of the attendants to open the water bottle.
***Disclaimer- be very careful and open little at a time until all pressure is relieved.***

Start car and let idle for 5 minutes, most of the dirty water will flow out of the water bottle.
Fill with new water. Should help you out for a few weeks more if cant get a rad flush done.

Make sure you check water level at night.

Cheers
 
ACTPerformance said:
I have the same problem on a similar car.

Turned out to be dirty water in the radiator.

If the water is a muddy red, its time for a radiator flush.

In the mean time, when the car overheats, stop at the garage and get one of the attendants to open the water bottle.
***Disclaimer- be very careful and open little at a time until all pressure is relieved.***

Start car and let idle for 5 minutes, most of the dirty water will flow out of the water bottle.
Fill with new water. Should help you out for a few weeks more if cant get a rad flush done.

Make sure you check water level at night.

Cheers
Click to expand...

Worst advice possibly ever. Dont drive your car until your problem is resolved.

Liftclub or taxi.

Dirty water wont make the car overheat. It will damage the waterjackets in your casing and head but it will still have the same heat exchange capabilities. There are causes for overheating. Have it checked out.

These guys have given good advice before. And dirty water isnt it.

Cracked head. Blown head gasket. Stuck thermostat. Those rocam thermostat housings are lank useless. They go brittle and break up and block the thermostat.
 
It was the thermostat.

Since its come from the repair place the battery light stays on under 3200 RPM... #justcantwin!!!! So probably the alternator is going or maybe the battery... SIGH!

Why only after its been with them? Coincidence I hope.
 
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