Date:         Mon, 5 Oct 2009 19:31:10 -0700
Reply-To:     neil N <musomuso@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         neil N <musomuso@GMAIL.COM>
Subject:      Coolant Temp Sensor Test. Generic vs VW.
Content-Type: text/plain; charset=ISO-8859-1

Hi all.

Temp/resistance graphs in my Vanagon and Mk3 Jetta Bentleys appear to
be the same. Based upon that, it may be that the Mk3 Jetta and Vanagon
sensors have the same specs. If so....

My VanaJetta swap has had a long standing intermittent hard start
issue when engine warm. Wasn't really a problem. But twice finding
this engine error: "ECT - Intermittent Short to Ground", finally got
me off my butt to check things out. Since I have the sensor that c/w
engine (Possibly OEM? Has VW stamp. Made in Luxembourg), figured I'd
test and compare it to the suspect no name sensor.

Heated each in water, 70F to boiling I see ~ 600 to 23 ohm difference. (below)

Ironically, since I chose to install a new one at time of swap, the
"VW" sensor seems within spec. The newer suspect one doesn't, but is
close. Since it was close.....

Do the resistance value differences between the two sensors indicate
manufacturing differences (possibly quality control) or is the No Name
just a failing coolant temp sensor?

Personally if the differences are due to lack of quality control, I'd
be tempted to spend the $ at the dealership if an OEM part can be had.

Neil.

Test pics:

http://picasaweb.google.com/tubaneil/ECTTesting#

Results:


On stove at "Med" to 80F, then "Max" to boil. At 212F for 1 min.
Converted to Celcius. Water stirred until boiling. Ignore the decimal
point!

         No Name             VW

21C  2900  Ohms       2300 Ohms
27     2440                  1920
32     1940                  1550
38     1656                  1300
43     1360                  1070
49     1130                    890
54       932                    750
60       780                    640
66       666                    530
71       555                    450
77       470                    380
82       400                    325
88       337                    278
93       286                    240
100     217                    194


--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"

http://tubaneil.googlepages.com/

http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines