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Sat Dec 20, 2014 11:34 pm

I have been trouble shooting a low temperature gauge reading and I decided to replace the thermostat. That cured the problem and the temp no runs normal. But I discovered the old thermostat is marked 113-121 F. So the question is why would the PO put in such a low temperature thermostat? I'm guessing it was a mistake or maybe to correct a overheating problem. My Westy came from Texas and that's about all I know of its history.
Any ideas?

Sun Dec 21, 2014 12:44 am

Maybe he couldn't find an application specific unit and decided to use whatever fitted? Anyway, good to see that you replaced it; having the engine run too cool will cause it to use more fuel.

Sun Dec 21, 2014 6:34 am

The stock tstat is pretty easy to find - but I have to wonder where the heck he found that cold one.

I suspect you're right, a misguided attempt to address an overheating issue. Thermostat set the minimum temperature of the engine, not the ultimate maximum.

Sun Dec 21, 2014 8:35 am

It is a simple case of misinterpreting the markings on the thermostat.

Those numbers and letter are part of the VW part number. They are not the temperature.

Vanagon WBX thermostat_ 025 121 113F

Vanagon diesel thermostat_ 068 121 113H

New Beetle gas thermostat_ 044 121 113
New Beetle TDI thermostat_ 050 121 113C
Passat VR6 thermostat_ 075 121 113D

Mark

Sun Dec 21, 2014 10:26 am

crazyvwvanman wrote: ...Those numbers and letter are part of the VW part number. They are not the temperature.

Vanagon WBX thermostat_ 025 121 113F...

Hah! Nice catch.

Sun Dec 21, 2014 10:34 am

Bazzer485 wrote: That cured the problem and the temp no runs normal.

So bad thermostat?

I have the opposite thing going on. After new rad, water pump, and tstat last winter, the bus ran hotter all summer, needle on (not under) LED.
Been checking hose routing, all is well.

I guess the gurus are right when they say test 'em on the stove first.

I will be boiling up the next one!!

Sun Dec 21, 2014 1:53 pm

crazyvwvanman wrote: It is a simple case of misinterpreting the markings on the thermostat.

Those numbers and letter are part of the VW part number. They are not the temperature.

Vanagon WBX thermostat_ 025 121 113F

Vanagon diesel thermostat_ 068 121 113H

New Beetle gas thermostat_ 044 121 113
New Beetle TDI thermostat_ 050 121 113C
Passat VR6 thermostat_ 075 121 113D

Mark
Thanks, I guess my problem was a thermostat that was opening to soon

Sun Dec 21, 2014 2:03 pm

[quote="wecm31"] Bazzer485 wrote: ...the bus ran hotter all summer, needle on (not under) LED...

Sounds normal to me.

In any case, I regard the temperature gauge as a warning device rather than an accurate diagnostic tool. If I want to know the operating temps I use an IR thermometer.

Sun Dec 21, 2014 2:47 pm

80 C and 87 C is the temp thermostats out there. 176 deg and 188 deg.