Audi gauges

[Toby_Unna]

Well I've (nearly) got these working now, and i'm starting to look like a lobster, so time for a break and a new thread

sensors arrived today, decided just to install them on the turbo oil line, seems as good a place as any... and bollocks to giving demon tweeks any money for an adaptor too, i soon found some suitable scrap in the shed






welded and oil tight




start-up vid




warm-ish idle - is 3 bar in the right area?




unfortunately it isn't all rosy - the oil temp gauge just goes full scale when connected to the sensor, and zero when unconnected. the gauge itself is ok because it gives a mid-reading when connected to the water temp sensor instead, so i'm assuming the oil temp sensor is either buggered or mismatched to the gauge? (they came from different places!)

not a huge prob really as the temp sensor is far far less expensive than the pressure sensor to buy new, but obviously would be nice to get it working!

in a curious rush of productivity i've also managed to get the gauges lit and dimmed with the rest of the interior lights which looks nice, must be the heat or something

[E30BeemerLad]

Toby - the fred Dibnah of all things M30 turbo haha

You still at PPC or was there a petition from MK3 Supra owners to get you banned lol

[d1mmy]

Nice work Toby, what audi are the gauges from

Thanks for the parts.

[FlappySocks]

Looks great. I was thinking of doing the Audi gauges. Very reassuring to have oil pressure. Instead, I plan to make a small touch screen LCD panel for Megasquirt, and maybe have an auxiliary input for oil pressure. (If I ever get time that is!).

A Jag I used to have had an oil pressure gauge. It never moved from the center - I later found out that Jaguar rigged it, to always sit there!

Stuart.

[ric325i]

nice work! looks good in the centre console

are you putting any more stuff in ppc about the e30?

[Toby_Unna]

Dimmy, gauges from an audi 90 or something, not too sure what model exactly but they're very common.

it'll be back in the mag soon enough... as Lee suggested, i've been lying low for fear of further retaliation from the (somewhat deluded) members of the supra mkiii club

gawd know's what's happening with the temp sensor, can't measure any resistance at all between output pin and body, seems to be completely open circuit

[d1mmy]

All sounds double dutch to me.

But great reading

[Theo]

I pillaged a set of these from a scrapyard yesterday including the temp sensor, pressure sender and most of the wiring from an audi coupe 2.6 v6. Was wondering how you were getting on with them Toby, sadly you've cheated and used your tubro oil line! So I will have to figure it out for myself.

When I get a minute I will check the resistance on my sensor to see how it compares.

[Toby_Unna]

Hmm

might have it worked out...

is it possible the smaller sensor in the top pic is an oil light (pressure) switch rather than a temp sender?

...because the temp gauge sits at the min right up until you start the engine, then it goes to max.

the sensor is also marked 1.8_0.2 bar underneath, i assumed that was the working press for a temp sender but i'm starting to wonder!

isn't ebay great!

[Theo]

Oh yeah. Thats the pressure switch mate, the temp sensor is smaller and has a different connector on it, not a spade. I knew it looked odd in the photos. I think Jon said they are £5 new anyway?

[Toby_Unna]

lol

yeah just checked the part numbers myself

good result tbh, means there's no fundemental problem. I'm just hoping the thread on the temp sender is the same, otherwise it's more grinding and welding (and looking for bits of scrap in the shed!)

[Toby_Unna]

btw theo, oze30 posted a good link a while back:

http://www.cscoupe.org/tech/gauges/gauges.html

made the wiring dead easy!

[Theo]

Very useful link, thanks very much for that.

I want to get hold of an e28 oil cooler and filter housing and fit the temp sensor to that. Now where have all the rotten E28's gone!?

[Jon_Bmw]

Hmm

might have it worked out...

is it possible the smaller sensor in the top pic is an oil light (pressure) switch rather than a temp sender?

...because the temp gauge sits at the min right up until you start the engine, then it goes to max.

the sensor is also marked 1.8_0.2 bar underneath, i assumed that was the working press for a temp sender but i'm starting to wonder!

isn't ebay great!

I think you are right, basically using the oil pressure switch light will give you either a on or off signal. Hard to explain but if you have good oil pressure the switch light would be off, represented by 1 for example, this then gets translated on your gauge as max. When its turned off, no oil pressure, so switch sends a 0 code and the gauge is then to 0. I think that if you experienced less than 0.2 bar, the gauge would drop to 0 and normally the pressure light would come on.

Thats my thinking anyway. I think the proper sensor should be about £7 ish + VAT.

My audi registers 5 bar on cold start

2 bar on Hot idle

5 bar at anything over 1700rpm ish.

I'm not sure how sensor location affects the readings given though.



Also good to have this in a seperate topic as its a question that is quite common.

[march109]

Do a quick search theres all you need to know in a similar thread started by e30adam.

[Toby_Unna]

Jon, that was my thinking. replacement sensor is apparently on its way

March, i just put the thread up with a few pics for info and to show how i installed the sensors. I'm sure if people get stuck they will search, though no-one except buster actually seemed to end up with a set of working gauges in the thread you refer to

[Andy335Touring]

Looking good mate

If i can figure out which way the oil flows through the oil filter housing i could tap a hole for the temp sensor and then may be tee-off the stock pressure sensor for the new pressure sensor ?

[Toby_Unna]

sounds like a good place to put the temp sensor mate. i'm quite pleased to have the pressure sensor at the top of the engine, certainly quite revealing

isn't there some issue with e34 filter housings where the oil drains back overnight? because watching mine build pressure after sitting for a long time is a bit will-it-won't-it

no temp sensor today, i want it all working now!

Edit, just remembered mine's an e28 filter housing now anyway

[buster]

Hi Toby,
the temp sender isn't working because you've got the pressure switch.Thats why it reads full or nothing.The same will happen if you connect it to the other connector on the pressure sender as its a secondry oil pressure light for the dash.
I used an e30 m3 temp sender for mine when i had the 325 engine and then the s50 temp sender for this one but its probably the same.
Heres a pic of mine (old pic though,dont have the chrome tat in there anymore ! ) :



and the audi sender and m3 one as fitted when i had them connected to the 2.5 :





cheers,
andy

[Toby_Unna]

still not quite there

got the oil temp sender today, but with it fitted the temp gauge reads low - never above 70-75 even with the engine properly hot (1/2 hour running time)

the sender says 180 degrees on the side of it which i guess might be the problem, because the link above suggests most audi senders are 150 degrees?

http://www.cscoupe.org/tech/gauges/gauges.html

anyone able to look at what their audi sender says on the side? or measure its resistance? or tell me what the temp range of an M3 sender is?

where can i buy a new one?

[Jon_Bmw]

It might not be a problem dude , I thought mine didnt work for ages as it sat so low. Only after half an hour of pure dangerous driving did it come off 'near the bottom'

[Toby_Unna]

better have another go and be more dangerous this time then

thanks Jon

reassuringly the pressure gauge gives similar results to yours - 2 bar hot idle, near 5 bar with a few revs on. so my engine isn't totally fooked

[Jon_Bmw]

reassuringly the pressure gauge gives similar results to yours - 2 bar hot idle, near 5 bar with a few revs on. so my engine isn't totally fooked

Good good, thats how a healthy engine should be.

[Demlotcrew]

A healthy engine or pump?

[Jon_Bmw]

A healthy engine or pump?

Too true when I think about it. Well mine isn't pinking, producing its power, no nasty noises, good oil pump so I call it healthy

[Toby_Unna]

another small update to this... it looks like Jon was right and my temp gauge/sensor are indeed doing what they should. I wasn't convinced so I put a long wire on the sensor and dunked it in a kettle of boiling water

this is what the gauge looked like, seems in the region of 100 degrees to me.



The only thing I'd like to know is where in the oil circuit the pressure switch tapping (i.e. where my turbo oil line feeds from) is - are there hotter places I could situate the sensor, in the filter housing maybe (or would that be cooler having come straight from the sump?)

during normal driving/lots of hot idling with the coolant temp right up it never gets beyond the end of the thick 60 mark which can't be more than 65-70 degrees?

at least it's reading right i guess!

[Theo]

Suprised that the engine runs that cool, but as you say the sensor seems to be working fine. 170 C is obviously just a bit overkill!

[Jon_Bmw]

To get to 170 I am certain you would need to be between 6000-7000rpm constantly doing burnouts(no air flow over the oil cooler) for AGES

I've sold the turd and never got round to finding out where the sensor was located, sorry about that but to be fair it always read between 60 and the first dash on the gauge anyway.

[Toby_Unna]

what oil cooler lol

useful to know how the Audi behaved Jon

[Aziz]

Hi

I have just bought a set of Audi Gauges but with no sender units

Can anyone tell be where I can possible get a Oil Pressure Sender Unit and a Oil Temp sender to fit.
The gauges are out of a 1996 Audi Quattro V6

Thanks
Aziz