01 Jetta Unusual Temperature

ClassicWolves · Nov 3, 2017

2001 Volkswagen Jetta GLS, 2.0 AZG Engine. Manual Transmission.

Ok i know this sounds as stupid as it looks. But i had one hell of an unusual issue today while driving. My Jetta suddenly dropped down to 0 on the Temperature gauge and the Heat stoped blowing hot, so i turned off the heat and turned it down to cold I noticed the temperature coming right back up, and the heat is able to blow again. I turn the heat back on and it does it again... so i do the same thing and once again it comes back to normal operating temperature and stays there like nothing ever happened and i was able to leave the heat on for quiet some time. I have no idea what the heck happened. Coolant was still full and proper, no coolant hoses popped off, everything looks normal. Any suggestions?

Extra Notes: It did have a P1296 but that cleared as soon as it started acting normal again

Uwe · Nov 3, 2017

Sounds to me like your thermostat hung in the open position for while.

-Uwe-

ClassicWolves · Nov 3, 2017

Well it sure was the craziest thing I've ever happen. Ive never heard of a Thermostat temporarily sticking open. Also thanks for moving the thread i wasn't able to delete it. Ill defiantly have to change the coolant and the Thermostat as well. It scared the bajeebers out of me because this has happened once before, but instead a Coolant hose blew completely off and the gauge didnt go to Zero til The Oil Light came on, but that was an 1995 VW Jetta.

Jack@European_Parts · Nov 4, 2017

2001 Volkswagen Jetta GLS, 2.0 AZG Engine. Manual Transmission.

Ok i know this sounds as stupid as it looks. But i had one hell of an unusual issue today while driving. My Jetta suddenly dropped down to 0 on the Temperature gauge and the Heat stoped blowing hot, so i turned off the heat and turned it down to cold I noticed the temperature coming right back up, and the heat is able to blow again. I turn the heat back on and it does it again... so i do the same thing and once again it comes back to normal operating temperature and stays there like nothing ever happened and i was able to leave the heat on for quiet some time. I have no idea what the heck happened. Coolant was still full and proper, no coolant hoses popped off, everything looks normal. Any suggestions?

Extra Notes: It did have a P1296 but that cleared as soon as it started acting normal again

I think you might of just found your P0420 code being sporadic too.........

No heat = no proper exothermic reaction!

http://forums.ross-tech.com/showthread.php?12152-2001-VW-Jetta-Catalytic-Problem

Please also try the fattening of the fuel trim output using FPR & to see how it effects amplitude of the CAT test after sorting the T-stat.

0x01-04-046

ivagp · Nov 5, 2017

Time to check fluid level. Could also be a possible water pump impeller or propeller whatever you want to call it. While you have the thermostat off inspect if the impeller on the water pump spins. Also there is a possibility of combustion entering the cooling system creating a pocket of air.

ClassicWolves · Nov 6, 2017

Close thread, issue was resolved.

ivagp · Nov 6, 2017

it would be proper to tell us ur fix before saying "Close thread, issue was resolved"

ClassicWolves · Nov 9, 2017

Thermostat was stuck open. It was a non-oem, So it was replaced with an oem.

01 Jetta Unusual Temperature

ClassicWolves

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Uwe

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ClassicWolves

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Jack@European_Parts

Gone But Not Forgotten

ivagp

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ClassicWolves

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ivagp

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ClassicWolves

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