AGAIN!

 

Was my car now my eldest son's. It went just over two years ago so I am surprised but to make sure it is not some sender or what I am going to do a scan on his car tonight to see what it shows. Not holding much hope though. He did manage to stop the car this time within a few yards unlike last time when he "drove" to get some more oil! So if it is it will be just the £6 hex drive and ten hours of labour to replace it.

Edited 23 August, 20169 yr by Danny 57

Find the pressure switch and check that there isn't oil coming out of it. Probably a one-wire connection.

Which engine code are we talking about?

I don't what engine code it is but it is the 2.0 engine (2007 L&K). If I can I will have a look at the wire.

I did a scan and it did not show any oil pressure related problem, plenty of others! It is now in a specialist independant VW garage.

The oil pressure monitoring is much more sophisticated than "a switch with one wire coming out of it". The oil light on the dashboard is not actually a true indication of oil pressure - when you assemble the oil filter dry, the light still goes out immediately the engine is started. Like the temperature gauge, the display is "sanitised" to avoid indications VAG don't want you to see.

 

In my experience, the science of deception at VAG may be rather older than we think.

 

So, the instrumentation is useless and the 2.0 PD engine is certainly a liability. VAG knew perfectly well that this engine was a lemon (as fitted by Audi) before it was ever used in the Superb. A nice bunch to do business with....

 

2.0 PD engines are better now scrapped, or preferably sold back to a VAG dealer.

 

rotodiesel.

The oil pressure monitoring is much more sophisticated than "a switch with one wire coming out of it". The oil light on the dashboard is not actually a true indication of oil pressure - when you assemble the oil filter dry, the light still goes out immediately the engine is started. Like the temperature gauge, the display is "sanitised" to avoid indications VAG don't want you to see.

 

In my experience, the science of deception at VAG may be rather older than we think.

 

So, the instrumentation is useless and the 2.0 PD engine is certainly a liability. VAG knew perfectly well that this engine was a lemon (as fitted by Audi) before it was ever used in the Superb. A nice bunch to do business with....

 

2.0 PD engines are better now scrapped, or preferably sold back to a VAG dealer.

 

rotodiesel.

Roto, what Audi models were fitted with the PD140 2.0 engine?

The oil pressure monitoring is much more sophisticated than "a switch with one wire coming out of it". ...

 

So educate us, there is a pressure switch with one wire coming out of it, or there isn't?

Read this, referring to the electronics interconnects:

 

http://www.myarchive.us/richc/VW_TDI_with_PumpeDuse.pdf

 

If you google Audi 2 litre PD oil pump failure you will find the offenders. (pour yourself a beer first).

 

rotodiesel.

Read this, referring to the electronics interconnects:

 

http://www.myarchive.us/richc/VW_TDI_with_PumpeDuse.pdf

 

If you google Audi 2 litre PD oil pump failure you will find the offenders. (pour yourself a beer first).

 

rotodiesel.

 

Ctrl-f and the words 'oil pressure' gets no results in your linked document, so I don't expect much relevant there.

You didn't answer my question about pressure switch(es), it wasn't a difficult one?

 

Do you know that oil pressure switches have a failure mechanism that means they tend to leak oil through themselves when they die?

It's quite common.

 

Sure, there are other reasons why oil pressure may be low, or a spurious warning may be triggered, but it's usually best to rule out the simplest and cheapest possibilities first.

You have to read and understand the VAG system diagrams. 1970 British Leyland technology does not apply to these cars, they are complex and need a proper understanding of their design faults to fix effectively. Because of this, many of these cars end up in a mess in the UK. I'll end this discussion here.

 

rotodiesel.

Lame. Lol.

Well I am away for two weeks so will struggle to find out for at least a few days but will post when I know.

Danny, is it a petrol or diesel 2.0?

Wino, it is the diesel.

I'll see what useful info I can find about the oil pressure sensing system, unless someone else chimes in first.

Well the oil pressure issues are well documented and lamented on the 2.0 8v so although validating the oil pressure switch may be a good move I feel that hex drive is now round and not driving the pump.

Well the oil pressure issues are well documented and lamented on the 2.0 8v so although validating the oil pressure switch may be a good move I feel that hex drive is now round and not driving the pump.

Cheers, I'll carry on trying to establish how 'un-mystical' the pressure sensing system is, just for my own interest. Looking at Octy2 BKD current flow diagram (nearest I have to the right one) it's a simple normally open pressure switch connected -by one wire - to the instruments module?

Pretty sure you are right.

I've done plenty of oil pressure checks on these as its a known issue. The proper oil pressure tester plumbs into the oil pressure switch and then you install the switch into the pressure tester and connect the single wire back up. This means you can test the actual oil pressure and the function of the switch and wiring all at the same time.

Location, access?

The oil pressure switch is on the oil filter housing the same as any other PD iirc.

So quite easy to get to, to inspect.

 

Thanks Tech1e.

Well the oil pressure issues are well documented and lamented on the 2.0 8v so although validating the oil pressure switch may be a good move I feel that hex drive is now round and not driving the pump.

Done the hex drive two and a half years ago that's why I would be a bit but not totally surprised if it was the hex drive again. If it is at least the turbo should be ok this time as he stopped very quickly.

Btw it was my car until I sold it to my eldest son 41/2 years ago.

Edited 29 August, 20169 yr by Danny 57

Out of interest, did you change the balance shaft last time as well as the hex drive, or just the hex drive?

Just the hex drive. Why?

Cheers, I'll carry on trying to establish how 'un-mystical' the pressure sensing system is, just for my own interest. Looking at Octy2 BKD current flow diagram (nearest I have to the right one) it's a simple normally open pressure switch connected -by one wire - to the instruments module?

For what it's worth, which may not be much by the sounds of it, it appears your pressure switch is a normally open one with a ~0.7 bar threshold, connected to pin 10 of a 32-way connector at the back of your clocks by a white/grey wire . The pressure switch connects the white-grey wire to its metal body parts - and so chassis-ground - when oil pressure is above threshold. An intermediate 10-way connector takes the wire through the firewall. The circuit on another VAG car from a similar era is that ignition 12V, via a diode, is fed through a current-limiting resistor to this switch, and a device on the clocks PCB checks whether the voltage at the switch side of this resistor is 12V or 0V, below-threshold and above-threshold pressures being respectively indicated. Super simple.  The clocks may ignore the below-threshold indication if revs are below a certain level, but I haven't seen documentation of that for your engine, so possibly not. There may also be a minimum below-threshold time that has to be exceeded in order to trigger a warning.

 

It seems your engine code is BSS?

 

Good luck with it anyway, hope it's not this rounded shaft thingummy.