coolant system goes wrong?

TOYOTA COROLLA
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PSMANNES
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My wife owns a 1991 Toyota Corolla with 1.6L engine. I noticed the temp is way below operationg temp so I replaced the thermostat. The temp is imporved BUT not exact temp in center of the gauge. I checked both inlet outlet hose and noticed top hose is hot and below hose is cold. I thought it was backward but it is not as I checked the instructions with photos in it. So whats other possiblity goes wrong? pump or rad cap?

Thanks
Peter
Nov 27, 2007 at 1:22 PM
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MMPRINCE4000
  • ASE Certified Mechanic
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  • ASE Certified Mechanic
The lower hose comes out from the thermostat and will be cold until the thermostat opens.
Could be the waterpump, but it does take several minutes for the lower hose to get hot.
You should use a Toyota thermostat and make sure the small hole in the thermostat is pointing at 11:00.

Also the gauge may not be reading correctly.

If you take the radiator cap off, start the engine, when the lower hose gets hot you should see the coolant moving through the radiator.

If the lower hose is not getting hot, then the thermostat is not opening.
Nov 28, 2007 at 7:19 AM
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