VDO Temp gauge

Discussion in 'Mech Tech' started by Geraint Thomas, Jul 5, 2019.

  1. The oil temp gauge has never worked in my bus and following on from my last thread about the flickering oil light I thought it’s about time to sort it out. I have taken the gauge out and the wires all seem to be there and connected but the casing is cracked etc . Where is the sensor supposed to be ? And where would the wire that runs to the sensor be ? 1800 type 4 image.jpg
  2. As it wasn’t a standard fitting, the temp sensor wire could be any colour. Find the sensor on the engine and see what colour the wire is. It may even be connected at the other end ;)
  3. I can’t find the sensor! It’s not attached to the sump plate or sump plug . Am I looking in the wrong place ?
  4. That's where you'd expect it to be o_O. Not on the dipstick, is it (unlikely on a type 4)? How many cables does your gauge have? Should have a ground, a +12 supply, a lead for illumination, and...the mystery cable from the sender.
  5. You’re looking in the usual places but it might be in the oil pressure relief valve. Or maybe up around the pressure sender, although it won’t be much good if that’s where it is.

    Mine is in a tapped hole in the sump near the relief valve, but that’s unusual.
  6. It should have bulb, earth, positive and sender (marked with a T on mine)
    Wire to earth on the dash pod positive to a live when engine on
    Bulb wired to light switch or tagged into the Speedo bulb light.
    Then a long wire to the noisy cub'd and the sender unit normally tapped into the case somewhere? Follow the wire back.
  7. I’m pretty sure now the vdo temp gauge was never connected, I found the sender cable all 3 ft off it behind the kick board and I can’t find a sensor anywhere also !? So it’s time to start from fresh . Are the dipstick sender units any good ? Any recommendations welcome.
  8. The dipstick jobs work well on a type 1, but I think you’ll have to make other arrangements for a type 4.
  9. The wire was probably chopped when welding. Run a bit of trailer board wire from the dash to the back. Then you will have a protected wire and several spare cores.. so e.g. running the stereo off the leisure battery will become an option, or those LEDs in the rear wheel arches become a possibility..

    I use a dipstick sender which I curved away from the fan belt so it lays over on the air cleaner hose . I scratched dipstick marks on it too. Despite everybody insisting they are inaccurate, the matching VDO gauge ( bought with the sender) I have is within 2 degrees C of a digital thermometer poked down the dipstick hole.

    Be aware buying a random gauge may not be accurate : VDO made two different gauge ranges and each uses different senders for the same temperature reading.
    Lasty and Geraint Thomas like this.
  10. What dipstick sender do you use ? I see jk do a vdo kit , I says it’s suitable for type4 engine but it’s really long at 615mm
  11. Given the length of the oil filler, I can’t see these things being very suitable for type 4s (may be wrong). Do CSP do a sump plate with room for a temp sensor? They do for type 1s.
  12. I had one in my type 4. I've just thrown it on the floor of the garage cos it was so long and bendy it got in the way, so I now have a sender in a taco plate. The dipstick sender worked fine, I was just never happy with it being big, bendy and messy. But it worked.

    1979 Super Viking, 2lt type 4, Automatic
  13. Taco plate or drain plug, or oil pressure control valve or dipstick, in that order, IMO.
    jim mcglynn and snotty like this.
  14. Boat Yard Buses sell a taco plate, not cheap mind at £32


  15. I don’t know why sellers describe the short VDO dipstick sender as being unsuitable for type 4 engines and list the long one, the shorter 41cm one is perfectly good although you will need to bend the top to avoid the engine lid. It fits very neatly with minimal external protrusion, maybe 3-4”.
    Just make sure you leave enough slack on your wiring to allow it to be removed without bending.
    The long one is far too long, only half of it fits in the tube and the rest sticks out ready to get bent and in the way.

    Sent from my iPhone using Tapatalk
    snotty likes this.
  16. +1 Taco Plate from Boatyard :) That's how I did my Type 4.
  17. I found on my type one that the sender fitted to the plate read a lower temperature and didn’t react very quickly, I put it down to the air flowing over it.
    The dipstick sender worked much better and I managed to shorten it so it’s not so awkward.
    scrooge95 likes this.
  18. D9E6C93D-3EE0-4BC8-AFD4-B53BB13852C8.jpeg Silly question but which 1 is for the earth and for the sender ? They are brass and copper ? Apparently 1 should have a G on it but this 1 doesn’t, thanks
  19. I'll have a look at mine later, but if you've got a meter you can check. Set it to low ohms and measure the resistance between the dipstick shaft and each of the terminals. The ground terminal will be zero ohms, the sensor "G" a few tens/hundreds.

    Worth getting a 2-way female connector to hook it up. Then you can unplug it easily.
  20. Right, on mine the darker (copper) contact is the "G".
    Geraint Thomas likes this.

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