VDO Oil Temp Gauge Reading High!

Hi, Can anyone help? I've got a '83 1.8GTi. Car recently went to have the head refurbished/valves/springs etc. along with the addition of a Kent 270 Cam Kit and MOT/service. During the work, a small oil leak was detected and traced back to the sump gasket. The gasket was changed and everything was fine. My car went into the garage with a fully working VDO centre console oil temp gauge, but the Oil Temp would never display on the otherwise fully functioning MFA.
Since the work the VDO oil temp gauge now reads over 170degC as soon as you turn the car on. The VDO Oil pressure gauge still works fine (as does the VDO Battery Voltage gauge). The MFA still reads nothing ( eg. - -.–) until the car has been running for about 15minutes, when it reads a seemingly reasonable 90degC!!! The temp. also changes throughout the drive, so it seems that the oil temp sender is ok, but has been connected to the wrong gauge? How do I rectify this? I?d rather use the VDO centre console gauge as it is easy to read on the fly and looks totally stupid with a reading off the scale all of the time!!! But could both gauges be used? I've moved away from the area where the garage is, so I can't take it back! I?m rubbish with  electric stuff, aside from the most rudimentary of understanding!  :dontknow:
Any help would be greatly appreciated. I?m getting married this Friday (18/09/09)  8O , my car is being used to transport me + groomsmen to the church to go with the missus? 73? Karmann Beetle and the bridesmaids who?ll be in a ?69 bay camper!!! I?d really like the car to be fully working by then!… because otherwise the car is spot-on!!!   Thanks in advance!

the vdo gauge probl;em sounds liek the wire for it is earthing out somewhere on the engine, the mfa temp seems reasonable.  check for a green/black wire, this should be connected to a single pin sensor with a white wire.  I am unsure where the VDO gauge wire sensor is, also i dont know what the wire colour is either, but if you spot a single pin wire just sat loose somewhere thats probably it.

as for the strange readings this could be as you say due to the wrong sensor being used for the mfa gauge, so if you spot the green/black wire swap this for the loose VDO gauge wire and see where that gets you

FYI.

You were correct. The wires for oil pressure and oil temp where put back the wrong way round by the garage!!!!

I'm scouring the site for an answer and struggling to find what I need.

I have the high temp reading on the VDO gauge (around 110-120 when the housing temp is showing as 75-80 using my multimeter probe), no temp reading on the MFA at all. Its the original temp sender on the filter housing. If you feed the water temp signal into the gauge it also reads over 110 at water temp of 80. This would indicate to me that my gauge is reading high. Is there a fix for this other than get another gauge?

Alongside this fault I had a low pressure warning light flashing at idle (well I did after I re-connected the warning lights connector on the transmitter the previous owner kindly left off) and the gauge indicating low but I've diagnosed that down to the pressure sender as when I put an original blue switch in the low pressure light stays off and when I hooked up another gauge/ transmitter its showing a decent reading of 20 psi at idle not the 0-0.5 bar the cars gauge is showing. What pressure sender do I need that will run the gauge and the light ie twin post? If the gauge consistently runs low with a new transmitter I assume I'll be needing a new gauge as well?

Will this sender work OK? Has anyone seen the same quality or better cheaper anywhere else?
http://www.ebay.co.uk/itm/Oil-Pressure-5-bar-Sender-Unit-replaces-VDO-unit-Two-Post-warning-light-model-/370632380564?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item564b695094

the water sender is the wrong rating for both sensors, so that'll be why it reads wrong. there should be a white sensor for the mfa which has a green/black wire.

the sensor you need for the oil temp and oil pressure depends on which vdo gauges you have what rating are they both?

Yeah the water sender and MFA sender are the correct ones. I found elsewhere a tiny snippet of information that the oil temp sensor will not power two gauges I unplugged the gauge and the MFA is reading accurately so I've left that gauge disconnected now.
The gauges are 0-5 bar oil pressure 60-170 degree oil temp and the traditional voltmeter. Really I want the 50-150 temp gauge I think.

ah yes that would be why!

the 0-170 gauge might need an audi blue sender? have you tried running the vdo direct to the mfa sender on its own?

for the 0-5 bar gauge the link above will work fine, maybe check the numbers on the sender you have perhaps its a 0-10bar sender

I've re-instated the original equipment ie removed the plug for the dodgy temp gauge as it's obviously inaccurate and I'd rather know what the oil temp is when I've got low pressure warnings, coolant warnings etc.
I shall buy that pressure sender to sort out the low pressure warning and dodgy gauge reading and will probably try and source a 50-150 temp gauge rather than add an audi temp sender.