New S2 Avant Nothelle N300 owner

[twoqu]

Just looking at some available VDO senders and it does seem that they operate in the 10-184 Ohms range 0-5bar. The tolerence is large especially at the higher pressures where anything from 154 - 214 ohms is a 5 bar reading. In fact the bottom 5 bar tolerence is within the mid to high range tolerence of 151-162 Ohms for the 4 bar measurement.
So its true they are not a particularly accurate way of measurement but its a bit alarming to have a gauge pegged at max all the time!

[steve briance]

I can't remember from your thread if you ever had the engine running on collecting the vehicle. Its not beyond possibility that it had an incorrect one in there when you picked it up...
After rebuilding my engine 3 years ago and getting many many new bits for it including the cotton reel type vdo sender, I felt sick when I started getting oil warnings. The problem only manifested itself once I got confident enough to open it up a bit and then it stayed beeping and flashing!

Have a read through this lot and see if this sounds familiar to what you are getting...

https://www.s2forum.com/forum/techni...and-what-to-do

[Tractor Dave]

Thanks Steve.
I haven't bought a new one yet as I did read about compatible issues. I'm still in the original one. I did try a second hand original but that caused the auto check low oil pressure buzzer. Someone is sending me another

[steve briance]

I am experienced enough in unusual / unexpected oil warning lights on my auto check to comment... Check the part number of the cotton reel type sensor you have fitted. The ones audi use in these engines is different to the ones vw use in the golf family engine despite looking identical.

I have fallen foul of bargain hunting and fitted a brand new vdo oil gauge sender unit from vw heritage as unaware of any differences; it was significantly cheaper than audi. The internal switching contacts for pressure warning operate differently for vw and mine constantly triggered the beeping at 3000rpm.

If you have only just ventured there in your run in routine that my explain why you have only just experienced it.

Check the numbers or if unable to see any I would try a good second hand unit that can be verified as coming from a 5 cylinder engine.

You live and learn.

[Bowie69]

There's a switch on the sender as well, you sure you didn't measure that?

[Tractor Dave]

The only specs I have seen are from the AAN/3B for the pressure sensor. Doubt whether its different for the ABY.

5-10 Ohms - Engine off
70-120 Ohms - Idle
170-200 Ohms @3000 RPM

That is measuring from the G terminal to ground. So you can verify that the sensor is producing a signal that makes sense. You could also measure pre and after the connector to see if it varies. If it does then the issue might be the connector itself. If it passes through the connector ok then that leaves the wiring back to the guage.
It looks as though the higher the resistance the higher the reading!

Should say thats with engine oil at 80C!

More useless info. Found some VW1301 measurements that equate to oil pressure from the sender. You have to divide by 2 and add 10 to convert to resistance.

350 = 5.0 bar
150 = 2.0 bar
10 = 0 bar

So converted:

185 Ohms = 5.0 bar
85 Ohms = 2.0 bar
15 ohms = 0 bar.

Not as accurate as a guage but hopefully that should allow you to determine whether there is an issue.

Tested when the oil was warm.
Engine off - 10 Ohms
Engine running - drops to 0
Makes no difference if you rev the engine.
I think I need a new sensor.

[Tractor Dave]

How much force does it take to press the bearing into the carrier and the hub into the bearing?
I have had issues a couple times recently where the carrier/upright had corroded and the bearing bore was oversize meaning the bearing fit was not tight enough in the carrier resulting in slight play in the wheel.
It should take around 5T of force to install the bearing in the carrier and around 2T to press the hub into the bearing. If you can install either with much less, that will cause problems as the bearing is designed to be installed with a tight interference fit.

To be honest I wasn't watching the gauge. We used a 30t press. I think I'm going to have to take it all apart again and examine the carrier carefully to see if there is something preventing it going all the way. Thanks for your advice.

[Error404]

I don’t really know for sure. The first bearing had play so I ordered another new one thinking it was faulty. The second one, another SKF, also has play.
They were pressed in correctly with support. Maybe they are not seating in the hub carrier properly or the hub has wear. It looked good with no sign of corrosion or wear.


Sent from my iPhone using Tapatalk

How much force does it take to press the bearing into the carrier and the hub into the bearing?
I have had issues a couple times recently where the carrier/upright had corroded and the bearing bore was oversize meaning the bearing fit was not tight enough in the carrier resulting in slight play in the wheel.
It should take around 5T of force to install the bearing in the carrier and around 2T to press the hub into the bearing. If you can install either with much less, that will cause problems as the bearing is designed to be installed with a tight interference fit.

[Vorsprung durch Technik]

Then this afternoon I went for a spin and did some altitude testing.




Sent from my iPhone using Tapatalk

Lovely, looking great and in it's best environment out on the road in interesting scenery enjoy!

[Tractor Dave]

Then this afternoon I went for a spin and did some altitude testing.




Sent from my iPhone using Tapatalk

[Tractor Dave]

What is the problem with the hub and/or hub carrier?

I don’t really know for sure. The first bearing had play so I ordered another new one thinking it was faulty. The second one, another SKF, also has play.
They were pressed in correctly with support. Maybe they are not seating in the hub carrier properly or the hub has wear. It looked good with no sign of corrosion or wear.


Sent from my iPhone using Tapatalk

[M2ki]

What is the problem with the hub and/or hub carrier?

[Tractor Dave]

I needed to take some pics for the agreed value with the insurance co.
So, gave her a quick wash.









Just a few things to sort now. The rear wheel bearing, the centre interior light, the oil pressure gauge and of course the paint.

Has anyone got a spare S2 Avant rear hub? I don’t want to waste another bearing until I know what the issue is. It’s either the hub or the hub carrier.


Sent from my iPhone using Tapatalk

[Error404]

Just buy a branded 10bar mechanical gauge, it will be fine and accurate enough for general testing purposes
You’ll need a short hose too, to connect it. The OEM sensor positions are really the only option you’ve got -they are supplied from the main oil gallery so ideal
Smaller upper thread is M10x1.0. Larger lower thread is M16x1.5, OEM adapter takes it down to M10x1 also
HTH
Alex

[Tractor Dave]

Cheers Alex. I'm glad you explained the spring/shim stuff as I'm not qualified or sufficiently knowledgeable to comment

I didn't get time today but will hopefully have a play tomorrow. I haven't bought an oil pressure gauge yet as they were too many to choose from and I didn't want to buy the wrong one. Would you take a reading from where that sensor sits?