Overheating engine

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Mrfoxvdub
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Overheating engine

Post by Mrfoxvdub »

Hello all need some help sourcing my problem
I drive a 1.3L vw fox, and have I've been having some overheating problems.
Bought a new radiator, and thermostat(which my car didn't have one).
Started it and left it to idle until the temperature gauge got half way(when the fan is supposed to kick in) and it just doesn't come on, i felt the top hose is hot but the bottom one is still coldish. I also fitted a new temperature sensor to the radiator but the fan still doesn't want to come on?
Now i don't know if the thermostat isn't opening or is it something else?
Any solutions plz guys
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Jetta2
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Re: Overheating engine

Post by Jetta2 »

Thermostat is not opening from your description.
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Mrfoxvdub
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Re: Overheating engine

Post by Mrfoxvdub »

Its a new thermostat though. Maybe it was installed wrong or what?
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Jetta2
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Re: Overheating engine

Post by Jetta2 »

New thermostats can fail to open.
Always test a new thermostat by putting it in boiling water to see if it opens, before installing it.

The bottom radiator hose should get hot when the thermostat opens to prove that coolant is in fact flowing through the radiator. It not, it is the issue.
Either that or the water pump has packed up.
Ryan Demoser

1996 Mk3 Golf VR6
2017 Caddy Maxi Crew Bus 2.0 TDI
2013 Aprilia RSV4 track toy
2021 Aprilia RS660 road bike
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PapaJo
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Re: Overheating engine

Post by PapaJo »

Could be airlock due to new radiator installed. Fil up with water when motor is cold and start, let car idle and pump top hose to get air bubbles out. Once no more bubbles and water getting hot and bottle stay full, close the cap and idke till operating temperature is reached. If fan didn’t cane on yet, let motor and water cool down and repeat. If still no fan switching on and top hose is hot the thermo temperature switch may be at fault and needs replacing.
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panic-mechanic
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Re: Overheating engine

Post by panic-mechanic »

Top and bottom hose must be hot before thermo switch will kick in. Water does not circulate the radaitor unless the thermostat opens, which is indicated byt the bottom hose warning up.
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