Temperature gauge not working?
NEWS
 
+ Reply to Thread
Results 1 to 11 of 11
  1. #1
    Neutral
    Join Date
    Jul 2008
    Posts
    5

    Temperature gauge not working?

    Hi,

    I have a 1999 Passat V6 that I recently bought (used). I recently noticed that the temperature gauge on the dash seems to be faulty.

    Sometimes the needle goes to the middle (190 degrees) only to slowly fall back to zero after a while (or not - it's random). Other times, it remains at zero and never moves even after the car has been running for a few miles. No CEL though. I hooked up an OBD-II code reader - no pending codes either.

    Any ideas on what might be the issue? I'd appreciate any help.

    Thanks!

  2. Remove Advertisements
    VW Passat Forum
    Advertisements
     

  3. #2
    3rd Gear
    Join Date
    Feb 2004
    Location
    Atlanta
    Age
    31
    Posts
    1,452
    coolant temp. sensor is shot.

  4. #3
    Neutral
    Join Date
    Jan 2008
    Location
    Tennessee
    Posts
    38
    x2. i had to change mine for a CEL. it's that sensor.

  5. #4
    Neutral
    Join Date
    Feb 2005
    Location
    Virginia, USA
    Posts
    59
    That's the symptoms that describe needing a new coolant temp sensor. There are a number of threads around here covering it. VWOA put out a warranty extension to cover it too, so you might be able to get it replaced free of charge if you look into it.

    I found that the location of the temp sensor varies greatly from one engine rev to another. For example, I found that many earlier 1.8T engines had it in a rather convenient location for access while my AWM was a major PITA. I don't recall about the V6 placement, but I'm sure it's discussed if you search.

  6. #5
    3rd Gear
    Join Date
    Feb 2003
    Location
    Hamden, CT USA
    Age
    41
    Posts
    2,214
    Quote Originally Posted by musk View Post
    That's the symptoms that describe needing a new coolant temp sensor. There are a number of threads around here covering it. VWOA put out a warranty extension to cover it too, so you might be able to get it replaced free of charge if you look into it.
    Despite the part number being the same, the warranty extension does not apply to the V6.

    Here's how you change it on a V6:

    http://www.tobio.info/passat/howtos/...nsorhowto.html

  7. #6
    Neutral
    Join Date
    Jul 2008
    Posts
    5

    Follow-up question

    Thank you everybody for your help.

    I read some of the other threads that seem to cover similar issues. Here are my concerns/ follow-up questions:

    1. Most other threads talk about the problem where the temperature guage shows heating. (in my case, it never heats - its either in the middle sometimes slowly falling back to zero or remains at zero).

    2. Some of the other threads suggest that there could be a problem in one of three areas - bad coolant temperature sensor, bad thermostat or bad connections?

    Can you comment? I appreciate your help.

    I'm a total newbie and recently learnt how to change the oil on my own <--- that's the extent of my knowledge about cars!

  8. #7
    1st Gear
    Join Date
    Jun 2008
    Location
    Atlanta
    Age
    39
    Posts
    379
    Read here, it may help: In my case it was the connections corroding.
    Last edited by luxuryedition; 11-26-2008 at 03:26 PM.

  9. #8
    Neutral
    Join Date
    Jul 2008
    Posts
    5

    Coolant?

    Thanks!

    Will I leak any coolant while replacing or removing the coolant temperature sensor (to apply dielectric or to replace the coolant temperature sensor)? Should I buy more coolant as well?

  10. #9
    3rd Gear
    Join Date
    Feb 2003
    Location
    Hamden, CT USA
    Age
    41
    Posts
    2,214
    Read my instructions, first of all.

    You will lose a couple of teaspoons of coolant, at most. Make sure you do it with the engine cold.

    I would purchase the coolant, spring clip, and o-ring and replace them anyway. Apply dielectric crease to the connector when you reinstall.

  11. #10
    1st Gear
    Join Date
    Jun 2008
    Location
    Atlanta
    Age
    39
    Posts
    379
    Quote Originally Posted by Roger1975 View Post
    Thanks!

    Will I leak any coolant while replacing or removing the coolant temperature sensor (to apply dielectric or to replace the coolant temperature sensor)? Should I buy more coolant as well?
    You will not leak any coolant to apply die-electric grease, just undo the electrical connection and apply, then reconnect the connection.

    When removing the sensor, the coolant will squirt a little, not enough to go and purchase new coolant to top off (unless you are low to begin with).

  12. #11
    Neutral
    Join Date
    Jul 2008
    Posts
    5
    Thank you, everybody!

    I'm going to replace it this weekend.

  13. Remove Advertisements
    VW Passat Forum
    Advertisements
     

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Powered by vBadvanced CMPS v4.1.2