Hey guys, asking for your knowledge again. The mk2 is running now, but is showing the same issues with the oil light it was when the engine was still in the old car. The oil light starts blinking when idling, or when driving at lower revs. Previously, when the engine was still in the other car (over a decade ago), I remember the light would go off and stay off for a while after reving it up a little. Now though, the light goes from blinking to being on all the time when revving. When I then again let go of the gas, the light goes back to blinking. Not sure which sensor on the exchanger goes where, so I tried it both ways, and also connected the wires both ways in both situations. Putting the connectors the other way around changes the oil light's behaviour from blinking at low revs and being on at high revs, to being on all the time. The sensors are new, and the issue was the same before and after the swap of the sensors. I already had the oil pan off and checked for debris in the pump's filter, but found nothing. If anyone has any ideas, let me know please. The engine despite these lights ran just fine in the old mk2, and is running equally fine (if a bit lean (tips on this are welcome too)) in the current one. If anyone can tell me with a 100% certainty where the white and where the blue sensor goes, and which wire yellow or blue, is connected to each, that would be a great help too already.
in terms of function it doesn't matter which way round you fit them in the filter housing, but the white 1.8 bar switch is at the back with yellow wire, blue 0.25bar or brown 0.3bar switch at the front with blue.black. Check the ratings for both switches as the colour codes on aftermarket types doesn't always match up to oem. the low switch should be closed circuit engine off and idling, the high switch open circuit engine off and closed circuit when oil pressure reaches 1.8 bar. for testing if you earth the blue/black wire the light will come on with ignition, disconnect it the light should never come on. if you leave the yellow wire disconnected the light and buzzer should flash when engine is revved to around 2k rpm, if you earth it the light and buzzer shouldn't come on when revved.
Completely forgot to check back in on this thread with all the stuff that's been going on lately. Anyway, I already put them both ways, both the sensors as the wires, and it keeps giving the somewhat same results. In any case, the light blinks or stays on. I now installed a mechanical VDO meter, directly to the heat exchanger where the oilfilter is mounted to. It basically screws in to one of the holes originally meant for the sensors, and does not rely on electronic input, but is directly operated by the oil itself. This meter now gives a pressure of somewhere around 2 bar with stationary cold engine, which gradually drops to well below 1 bar for a stationairy warm engine. It goes up to around 5 bar when driving / revving. Installing this meter also means I had to take out one of the sensors. Now, the light on the dash blinks, until I go a bit over 2 bar (I guess this is the 2.3 bar it says on the sensor). Above this number, it just stays on without blinking. Dropping below that number again, means it starts blinking again. Then another thing.... The oil temperature. The temp gage on the Digifiz cluster worked fine I think, but I also wanted to use the VDO meter that was installed in the Votex console. now that I did that, the meter in the cluster does not work at all anymore (it gave off a reading of about 60 degrees celcius for the oil the first day or so, but only when the actual engine temp was a lot(!!!) higher. Now it shows ---. The VDO meter gives a reading of about 90 degrees, which should be fine, but heavilly fluctuates when for instance using the fan, or driving fast (lots of driving cooling by wind), use my highbeams, etc. How and where should I best hook this meter up so that I get an actuarate reading? I now have it hooked up under the dash, with the wire coming from the sensor on the back of the 16v engine. The same sensor used for the cluster's reading. At first I thought me using both meters on the same sensor and wiring, would screw up the reading, but ATM I really don't know...
ok so if the new gauge is accurate, you have low oil pressure. when cold my 5 bar gauge pegs over to max at idle, then when fully warmed up it sits at 1 bar. to check your pressure switch wires as i say, disconnect both. earth each one, whichever makes the light come on with ignition goes to the 0.25/0.3bar switch and the other oen needs to go to the 1.8 bar switch. oil temp on a std GTI mfa cluster wont read below 50 degrees, not 100% sure on digifiz but I expect its the same deal. you cant run 2 gauges off the same sensor by the way, you need one for the digifiz and another for the gauge you put in. you also need to make sure the sensor is the right rating for the gauge you put in, the mk1/2 mfa sender is different to mk3, and audi 170/180 gauge is a different one again electrically most of the ignition live feeds you have readily available will be affected by load, the oem ignition live pin as used on corrado with vdo gauges will fluctuate with the indicators for example, if you use an X-live this will fluctuate with blower motor, wipers etc. so long as you bear this in mind its no big deal. if you're really bothered you could run a live wire from the battery to a relay which then feeds your gauges and have that triggered by an ignition feed
