1990 Audi 2309cc 20v Coupe Quattro
 

Oil Pressure and Oil Temperature Gauges needed - also Senders as back up.
Also Diff Lock not working but unsure of problem - interested in any likely parts.
Thanks
Keith

got a set of gauges in the 90 sport I am breaking if your interested?

Thanks Ritchie
I assume these are identical on both models?
How much do you want?
Thanks
Keith

If no joy with Ritchie, try Mike on 07809 222346, he had a red one in for breaking, don't know if he still has it, worth a call( he js in Lockerbie):tup:

for your diff lock, check the pink pipe that goes from the inlet, along the bulkhead and behind the battery, chances are its split/cracked

Sam

Thanks for tip. I can see a small pinkish pipe (about 4 mm dia) behind and connected to right of battery but cannot see where it goes. Is that the one? No warning lights appear when Diff Lock button pressed but could pipe still be problem?

Keith

yeah thats the pipe, pull it off at the manifold and blow down it, you'll hear it if its leaking. it goes into bulkhead and end up under the back seat. if its not that then possibly the arm seized on he diff itself, but my moneys on the pipe

If it turns out to be the switch I have a spare or 2.

Oliver
Nice to hear from you - did try to contact you.
How much would a switch be? Also do you have any Oil Pressure / Temp Gauges or Senders?
Keith

Hi mate, didn't get any message? Never mind probably lost in the ether!

Not much, I'll dig out what I have, How does £6 posted sound?

I do have one more set of gauges left, but really want to keep them to be honest as spares. They are just the gauges in the fascia anyway, if your fitting them to a car without gauges you need the plastic surrounds and wiring loom really too.

Oliver
That's fine and I understand re Gauges. For your info, gauges are replacements (or spares if mine are OK) - my car has 3 gauges in centre console (2 oil and 1 battery)
Tried a few times on 2 Nov but messages bounced back as undeliverable - perhaps a server hiccup!
Pls confirm and I will send cash.
Thanks
Keith

No probs will do, will be tomorrow night now.

If your gauges aren't working at all I suspect a power supply issue.

Usually diff lock can be diagnosed by lying down next to rear axle and manually locking the diff [with engine running] - if light comes on and abs off, then that's loss of vaccum.
P.S. As far as I remember, switch can be swapped with ABS switch, only to use ABS switch permanently, some contacts needs to be resoldered to get light working. I think soldering what I done was only for light, cos' my A90q has ABS switch in place of genuine diff lock switch.
What's wrong with your gauges?

Oliver
Thanks for comment.
Temp Gauge moves up slightly but stays at that position - Pressure Gauge zooms to max (off the scale!) when ignition switched on. Have disconnected Sender for latter but no effect.
Keith

MSH
Thanks for your helpful Diff comments.
Pls see Gauge problems above in my reply to Oliver.
Thanks
Keith

Well, It's definitely not a gauge problem, so u can keep your gauges :)
What these two gauges does, when they are disconnected? Oil temp gauge does nothing - like yours. Oil pressure gauge goes to max - again, just like yours :) Oil temp sensor is located in oil pump at the front bottom part of the engine, in side which in UK is called "driver's side". Small sender with small wire attached. If u don't have any shield under engine compartment, by lying down u will be able to see it. But actually, if u aren't using that car hard, u probably won't see that gauge moving - Ok, I dunno about R5 engines, when I had my A80, which had 3A 2.0 8v engine with gauges for more than year, I saw that gauge moving only once - when I was sitting for half an hour in a traffic jam in summer.
Pressure gauge - well, usually ppls like to put incorrect wires :) Did u tried to swap wires on big sender? :)

MSH.
To clarify. Temp G: haven't tried disconnecting but I'm fairly sure it used to move as engine got warm but I may be wrong. Pressure G: Needle goes to max whether connected or disconnected. Cables should not be crossed as no one had messed with them prior to problem which started suddenly. However will try what you say.
Thanks again.
Keith

Well, if pressure gauge connector isn't misplaced, then probably wire is broken somewhere.

I can help you twice here.

Found the switch, I may even have 2, pay me for one if I find the other you get 2 for one!!
I'll be glad to be rid of some switches, could tile my bathroom with them!

RE. Your gauges. The fault you are describing is the oil pressure wire being disconnected, hence why when you disconnect it it does the same thing. You have power to the gauges (I suspect your voltage gauge works fine) and quite simply either the wires come off one end or more likely there is a break in the wire. Simple job to just run a new wire. That will solve your issue I promise. By the sound of it your worried your oil temp gauge isn't moving? If so that's also pretty normal, the needle barely moves on most cars, the engine has to be clicking hot to really register. So no issues there I suspect.

So hopefully that big job has turned in to a 15 min running a new wire for the pressure gauge!

Paypal to wildoliver@tiscali.co.uk for the switch please.

Diff Lock Update:
Have now changed Diff Lock switch (by gearstick) and:
- It now lights up when switched on and goes out at around 15 mph (possible that old switch just needed new bulb).
- The ABS warning light does not come on when Diff Lock switch is pressed (the ABS light is definitely working).
- Diff Lock still not working.
Does the above throw any more light on problem or do the previous comments still apply?
Thanks
Keith

Does the little green light light up? Or just the orange triangle? Did u check the pipe?

Haven't seen green light. Where is it? Orange Triangle lit up. Haven't checked pipe yet.
Thanks
Keith

its in the centre of the diff on the switch... check the pipe! ;)

Now got mechanic with Audi experience to look at it and told him what you had said.
He managed to make Diff Lock work and Green Light come on (he messed with rear axle). I drove up to around 15 mph and Diff Lock disengaged as it should but I still could not switch it off or on with normal switch.
He has spent a few hours looking at the wiring as he is convinced that there is a short somewhere and also that the Oil Pressure Gauge problem (needle flying to max. when ignition on) is part of same fault.
He feels that I may wish to suffer it rather than run up a large bill for tracing it.
Do you or anyone else have any comments or ideas how we can trace the problem?
Thanks very much for giving it thought.
Keith

I still maintain the oil pressure problem is just a broken sensor wire to the sensor. But if you do want those gauges I was keeping as spare I've decided to let them go.

If he fiddled with the back axle it suggests he operated the lever by hand, then the vacuum lock pulled it out as it should at 15mph. As the only diff locks I have played with are on the type 85 I'm working on at the moment you need someone to tell you whether vacuum/pressure is required to put in and throw out or part of the procedure involves a spring. I reckon you could be looking at a split pipe that is blowing out under pressure (and therefore not pushing lock in) but sealing under suction (and therefore pulling it out).

Really doesn't sound like a short somewhere to me.

Oliver

Thanks for reply.

Gauge: Please confirm that you are thinking: Disconnect but leave old wire in place and thread new wire through - outside of loom etc? If so, do you have any tips on its route? Also is this a special Audi wire or can it be made up?
I managed to get some used gauges but, as everyone said, the gauge wasn't the problem.

Diff Lock: Very good news. Vac Pipe end under back seat was split. Cut off bad end and all now working, including both warning lights on switch and ABS warning on dash.

As always, sincere thanks to you and everyone else for help and, in particular, for diagnosing the Diff Lock pipe as the likely problem.

Keith

No probs mate, if i can solve your oil pressure prob then 2 out of 2 would be nice!

Standard wire, I've made a few up now, nothing more elaborate than a spade terminal on one end and splice in to the gauge loom.

Oliver
Thanks for that.
One more point: My guy says that other items (as well as Gauge) are on the same circuit/fuse and he thinks problem is probably nearer Gauge than Sender (perhaps between Loom and Gauge). He is happy to fit new wire but I think he is uncomfortable not finding the actual fault or knowing where to connect at Loom. I don't fully understand the problem as I naively thought cable merely went between Sender/Gauge.
Anyway, can you just tell me where you would try to connect at the Loom end and do you see any problem?
Sorry to be a nuisance.
Thanks very much.
Keith

Not a nuisance at all mate. you literally do just need a connection between gauge and sender. Literally a straight piece of wire about a metre long. Your chap does seem to be making a meal of these problems, to be honest I suspect he's either out of his depth or stringing you along for labour!

The gauges are so simple, 3 wires on the oil gauges (2 on voltmeter but it works in much the same way) positive and negative (to power the gauge if you like) and then a sender wire which just runs straight to the sender (in a factory fit it won't of course and will go in to the loom, but ultimately will have nothing else inline so while it appears to go in to the loom it's still just a straight bit of wire.

The sender switches down to earth, no power to it, the gauge just reads the resistance to earth and displays accordingly.

Thanks for very clear info.
Made up temporary cable and connected from Sender (big Sender near Rad) to Gauge to replace existing BL/W cable. Merely put spade connector on Sender end and pushed other bare end into connector on Gauge.
The Sender has another wire as well but not sure what that does.
Unfortunately Gauge needle still went to max. when ignition switched on.
Disconnected both cables at Sender but still went to max.
Tried another Gauge with same result.
Three different Gauges: Swopped plugs between Oil Pressure and Temp Gauges to see if power was making a difference but both Gauges acted the same, i.e. Pressure went to max. and Temp moved up slightly. At this point we did not have the temporary cable connected.
Are we doing something wrong? Is there any way of testing the 3 existing cables? Any other thoughts?
Thanks
Keith

The other cable is for the light in the dash display.

It can only be the sender unit now, you've eliminated the gauge/wire must be the sender.

Thanks for quick reply.

To date, no one has mentioned having a Sender for sale. Have I got to buy a new one or is it worth starting a fresh thread for one?

Oh, I may have explained it badly or am being thick, but I don't understand why the other cable on the Sender is for a dash light

As always, thanks for all the help.

Keith

Autocheck oil pressure warning is the other wire.

BMWs in scrap yards give up the senders too ;)

Because existing oil pressure senders are just switches, but manometer, for logical reasons, needs analog signal, so sender for it provides resistance that varies according to applied pressure, and to avoid need to drill a new hole in block or have one spare with plug in it, that sender provides both needed functions.
Pressure gauge, when not connected, goes up until max like yours does, and temp gauge doesn't moves. The same result for pressure gauge can be achieved if it's connected to incorrect pin on sender.

Are you sure these BMW senders provides correct signal? Which BMW has oil pressure gauge?

Thanks for comments.
Losing me a little regarding Temp Gauge as the wiring diagram seems to show it entirely separate from Pressure Gauge with its own sensor.
What do you suggest I try before purchasing Sender?
Many thanks

Actually it's a bit hard to understand your situation from your comments [and I didn't tried hard], so what are you doing - are you installing aux gauges in car which doesn't have them and never had before? What parts do you have?
Yes, temp sender is totally different [and small] and it's in different place as well - in 5 pot engines it's mounted in oil pump in front of engine. I forgot was it on right [driver's in UK] side or front, I think front. Wire originally goes around engine on it's right side. If your car doesn't have any mud guards below engine compartment, you should see it relatively easy - there will be either sender or plug in it's place.

Original Pressure Gauge (not fitting extras) which flies to max when ignition on. Looking at large Sender near Rad (UK Passenger/Nearside). My other posts above say what we have tried.
Thanks.

You have only one bare gauge and nothing else? Where are you planning to put it?
As I said earlier, it's normal that that gauge goes max without proper sender connected.

It is an original Gauge, i.e. the car is fitted (original equipment) with Oil Temp, Oil Pressure and Volt Gauges.
As already stated we have tried a new temporary Sender to Gauge cable but without success.
General feeling seems to be that it is a faulty Sender.
We are happy to try anything else.
Thanks