temp warning light

Dieseljack

Active member
Joined
Jun 4, 2004
Location
Washington
TDI
2004 GLS
I need some help, 2004 TDI Jetta, 5 speed manual. Yesterday my over temp light started blinking. I checked coolant level (same light?), and found it full. No other symptoms, temp gauge is, as usal, at a constant 190°. Any suggestions would be appreciated. Jack
 

CoyoteStarfish

Veteran Member
Joined
May 25, 2011
Location
Miami, FL
TDI
01 Beetle
If it is the same as the Beetle, flashing red is low coolant. As I recall an open circuit will cause this light to flash. You can pull the coolant level sensor plug on the reservoir and jump the pins with a wire/paperclip/etc. If the light goes out - bad sensor or connection corrosion. If the light stays on, bad connection or wiring. You can also use an ohm/continuity meter on the sensor itself to confirm the status of the float sensor.

In any case, a healthy dose of CRC contact cleaner and some dielectric grease can't hurt, even if turns out to be a bad sensor and will prevent any future corrosion issues.
 

Seatman

Top Post Dawg
Joined
Apr 23, 2010
Location
Scotland
TDI
2014 Skoda rapid elegance 1.6 cr tdi
A lot of guys over here just give the sensor a quick brush with an old toothbrush, seems to do the trick.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
The sensor probes get covered in gunk and then don't conduct. It starts happening only when cold and progresses to happening when the engine is cold, even in warm weather. Attempting to clean the probes may work for a while but it's almost impossible to get them completely clean. The reservoir is only about $20 and the biggest hassle in changing it is that to avoid a mess you need to partially drain the system (which means removing the belly pan to get to the valve on the radiator)
 

Dieseljack

Active member
Joined
Jun 4, 2004
Location
Washington
TDI
2004 GLS
Thanks very much ! Will give that a try, ohm meter will be easy check, clean connections, can't hurt .. Will let you know the results.. Jack
 
Top