Oil pressure/temp gauges

[what2do]

Now then, I've an oil change coming up and I was thinking of doing some prep for an upcoming task. Am I right in thinking there is a single sender unit for both pressure and temp that replaces one of the existing pressure senders? Cheers, mitch.

[marlinowner]

I bought a set of Audi gauges that came with a double sender, but it was a combined oil pressure sender and switch for the 0.3bar warning light. It replaces the original warning light switch. I then bought a separate oil temp sender.

[what2do]

My next question was what happens to the original 'early warning sensor, system when replacing it with different sensors. If I were to use the Audi product that you mention, how do I measure oil temp? Anyone????

[marlinowner]

Here is the thread where the temp sender was discussed before.
I was fitted the temp sender in place of the oil pressure "buzzer of doom" sender as my buzzer was disabled due to using an instrument set without that circuit.

https://club8090.co.uk/forum/viewtopic.p ... e#p8029704" onclick="window.open(this.href);return false;

[what2do]

Ok, thanks for that. My question is regarding the pressure sender that's about £50. I can't see from the pic what/how it's connected. Thanks for your help.

[what2do]

http://pages.ebay.com/link/?nav=item.vi ... 1589105592" onclick="window.open(this.href);return false;

Will these fit the bill?

[marlinowner]

Those gauges and senders on eBay are the same as mine, well worth a bid or two.
The £50 sender goes in place of the 0.3bar pressure warning switch on the engine (can't be very specific because I have the Audi engine in my van so am not that familiar with the boxer), the wire that was on the sender switch is then fitted to one of the spades on the new sender, the other spade connects to the guage. I have a photocopy of the relevant wiring diagram from the Haynes Audi manual if that would be helpful.

[what2do]

So am I right in thinking that in the cab, the wire which feeds the buzzer is disconnected and then connected to the new pressure gauge? Am I getting close?

[marlinowner]

It depends which double sender you have. If you replace the 0.3bar sender with a double sender, ie variable pressure and 0.3bar sender, then you refit the 0.3bar sender wire and run a new wire to the oil pressure gauge. Similarly if you replace the buzzer sender with a dual sender. Then you have to decide where to fit the oil temp sender. In my case I fitted the oil temp sender in place of the buzzer sender, because my buzzer circuit is disconnected at the speedo due to instrument PCB problems. This might not be ideal though because the temp sender would be best where there is a good flow of oil going past. Because the oil pressure and temperature gauges are mounted next to each other, it seemed neatest to connect them to the senders using twin core wire, leaving the buzzer sender wire disconnected at the engine.
Hope that makes sense!