Hi,

Does anyone knows for sure what is the exact job of the pressure regulation valve and how important is so I can evaluate my next steps?

 

The obvious answer is that its job is to regulate the oil pressure and I believe that this is critical, ok, but the thing is that it  is not generating a check engine warning light on the dashboard. Instead the fault is only stored in ECU and cannot be cleared. I’m using an OBDELEVEN scan tool. 

 

 

I'm not positive - but my best guess is that the oil pump is rated to supply a certain minimum pressure at idling speed - the pressure regulator valve would then bleed-off excess pressure as engine speed rises, to prevent possible damage to seals from overpressure.

Edited 27 March, 20242 yr by Warrior193
added information

2 hours ago, Warrior193 said:

I'm not positive - but my best guess is that the oil pump is rated to supply a certain minimum pressure at idling speed - the pressure regulator valve would then bleed-off excess pressure as engine speed rises, to prevent possible damage to seals from overpressure.

That makes sense. And if  i count the oil pressure switch that  if something goes wrong with the pressure it will give to the driver some indication of the fault, right? But if no excess pressure is build up at that point there is no critical state and that's why there is no an engine light on my dashboard?

The oil pressure switch will almost certainly only warn of a loss of pressure - not excessive pressure. I'd have thought that there would be a visual warning in addition to the OBD fault if the regulating valve had failed.

9 hours ago, VAskodas said:

Hi,

Does anyone knows for sure what is the exact job of the pressure regulation valve and how important is so I can evaluate my next steps?

 

The obvious answer is that its job is to regulate the oil pressure and I believe that this is critical, ok, but the thing is that it  is not generating a check engine warning light on the dashboard. Instead the fault is only stored in ECU and cannot be cleared. I’m using an OBDELEVEN scan tool. 

 

 

It's purpose is to allow the oil pump to run at reduced or normal pressure. 

1 hour ago, Warrior193 said:

The oil pressure switch will almost certainly only warn of a loss of pressure - not excessive pressure. I'd have thought that there would be a visual warning in addition to the OBD fault if the regulating valve had failed.

I believe that this is not the case cuz the engine has 1 pressure switch, one pressure switch for reduced oil, one oil pressure regulation valve and one oil level sensor/temp.sensor. So 4 in total. that's why i'm insisting on lets say high oil pressure switch. I may be very well wrong but that's my understanding. See photos.

As for the warning light, it's a mystery to me. Why it does not coming up on a dash board since it's a so important? Or maybe it isn't!! who  knows.

Edited 27 March, 20242 yr by VAskodas

1 hour ago, Warrior193 said:

The oil pressure switch will almost certainly only warn of a loss of pressure - not excessive pressure. I'd have thought that there would be a visual warning in addition to the OBD fault if the regulating valve had failed.

There is a reduced pressure switch and a normal pressure switch. Both only detect below spec pressure. Depending on if the pump is in reduced pressure mode or normal pressure mode. 

3 minutes ago, TheClient said:

There is a reduced pressure switch and a normal pressure switch. Both only detect below spec pressure. Depending on if the pump is in reduced pressure mode or normal pressure mode. 

O.K. That's something. So you are saying that when the oil pump is in normal mode only the normal pressure switch is working at that moment and when in reduced mode the other one works, correct?

And how about the oil pressure regulation valve sending a fault just only stored in ECU and not on the dashboard?

It has not sent a fault if the wording of the fault code is to be believed, and in this instance I think it can.

 

Electrical error indicates that the ECU is not measuring the volt drop across the solenoid when it is commanded, a failed solenoid or wiring fault.

 

If it was and when the valve was commanded the expected increase or decrease of pressure was not measured the ECU would create a fault code of oil circuit high/low pressure above/below limits or implausible reading.

 

The purpose of the high and low pressure regimes is for the piston cooling oil jets under load conditions.

Edited 27 March, 20242 yr by J.R.

1 hour ago, J.R. said:

It has not sent a fault if the wording of the fault code is to be believed, and in this instance I think it can.

 

Electrical error indicates that the ECU is not measuring the volt drop across the solenoid when it is commanded, a failed solenoid or wiring fault.

 

If it was and when the valve was commanded the expected increase or decrease of pressure was not measured the ECU would create a fault code of oil circuit high/low pressure above/below limits or implausible reading.

 

The purpose of the high and low pressure regimes is for the piston cooling oil jets under load conditions.

The piston cooling jet regime is additional and has its own pressure switch in a different locatikn to detect operation. It can activate in either reduced or full pressure mode. 

3 hours ago, VAskodas said:

O.K. That's something. So you are saying that when the oil pump is in normal mode only the normal pressure switch is working at that moment and when in reduced mode the other one works, correct?

And how about the oil pressure regulation valve sending a fault just only stored in ECU and not on the dashboard?

Yes. That's the purpose of the two pressure switches. They regulation valve controls the pump as dictated by ecu to toggle between reduced and full pressure mode. 

9 hours ago, VAskodas said:

O.K. That's something. So you are saying that when the oil pump is in normal mode only the normal pressure switch is working at that moment and when in reduced mode the other one works, correct?

And how about the oil pressure regulation valve sending a fault just only stored in ECU and not on the dashboard?

If the electrical fault is permanent you need to replace the n428. Edit. And or check wiring. It won't really damage anything short term, that's probably why no mil is commanded.

 

With the n428 not operating, I believe the default state is high or rather normal pressure mode. Not reduced pressure mode. That won't operate... 

Edited 28 March, 20242 yr by TheClient

Well eventually I replaced the valve and the error is gone! Easy job.
I took measurement of the new valve and the reading was 25 Ohm. On the old one it was open circuit, no readings.
I will try to somehow open the old valve to inspect what went wrong. I hope the delayed repair didn’t make things worse in the long run. 
 

After inspecting the guts of the valve I must point out that there is little to nothing you can do to repair it once it’s malfunctioning. I saw some people trying to use some lubricants or WD40 or Brake cleaner, none of these will work. It’s a simple electromagnetic valve with sealed coils, a spring and the actual valve that comes up and down. 
When you got the error you replace it and that’s all. 
 

PS I did this so you don’t have to. 

This is a fuel saving measure, nothing more, it's a similar system to that of the TDI. 1.8-2 Bar up to 3000rpm, 3.8-4.2 thereafter.

 

There are suggestions that oil temperature and engine load also influence the changeover point.

12 hours ago, SuperbTWM said:

This is a fuel saving measure, nothing more, it's a similar system to that of the TDI. 1.8-2 Bar up to 3000rpm, 3.8-4.2 thereafter.

 

There are suggestions that oil temperature and engine load also influence the changeover point.

 

Do you think the engine would benefit long term of the pressure switch actually not working and having full pressure all the time? As you stated it would only be a bar or two of pressure difference. I suppose if these engines were known to wear bearings or have oil starvation issues then it might be something to consider.

Edited 28 May, 20242 yr by Dooge

I would leave it as designed, you never know what other secondary issues it might cause, other manufacturers have been doing the same thing, it’s nothing new really

 

1 hour ago, SuperbTWM said:

I would leave it as designed, you never know what other secondary issues it might cause, other manufacturers have been doing the same thing, it’s nothing new really

 

Oh I will, just intrigued as to whether this is something that contibutes to engine failure across different platforms/makes, especially as Id imagine its an industry standard and has been for a number of years.

3 hours ago, Dooge said:

Oh I will, just intrigued as to whether this is something that contibutes to engine failure across different platforms/makes, especially as Id imagine its an industry standard and has been for a number of years.

I will agree. The only thing that confuses me is that it does not generate engine light on the dashboard. It’s like “oh hello, you have an OIL PRESSURE REGULATION VALVE ERROR but no worries, it’s fine I will not bug you with annoying engine light”

On 28/05/2024 at 16:17, VAskodas said:

I will agree. The only thing that confuses me is that it does not generate engine light on the dashboard. It’s like “oh hello, you have an OIL PRESSURE REGULATION VALVE ERROR but no worries, it’s fine I will not bug you with annoying engine light”

The only thing I can think is that if its not working, it just means you get full oil pressure. This is not an issue, in fact it could aid longevity for the overall engine Id imagine. Full oil pressure wont be anything excessive and from what I understand having read up a little about it, the valve only drops pressure under certain revs/throttle position/load to assist in fuel economy. For this reason, Id imagine its not something worth flagging up on the dash as its unlikely to ever cause any damage.

Hi there! - I’ve just got this error - how easy was it to change the oil pressure solenoid mine is superb 2.0 tdi clrb. 

How much was the part and the part no? Thanks guys - I’m new to diesels!

11 hours ago, M_Shaz said:

Hi there! - I’ve just got this error - how easy was it to change the oil pressure solenoid mine is superb 2.0 tdi clrb. 

How much was the part and the part no? Thanks guys - I’m new to diesels!

Hi, the replacement was very easy. Only removing the heat shield from the cable is required and a T30 torx bit. My Octavia is petrol so I can’t really tell if it will be the same on the  diesel superb. The cost for aftermarket valve was 63€ (incl. shipping). Your best chance is to find a valve for your specific vehicle and model and find the exact location of the valve. 
That’s from me. 

Great thanks - I think it’s a lot more difficult  on diesels 

On 10/06/2024 at 14:43, M_Shaz said:

Great thanks - I think it’s a lot more difficult  on diesels 

 
Hi, have you got this repaired? I think by talking about it I have manifested this very issue on my own car. 2.0 150 CR 92K Seems a common fault. 
 

No EML though, seems to have just been happy in high pressure mode. 
 

The solenoid is at the front left of the engine as you look at it I believe, will investigate this weekend but I’m 95% sure it will end up with a new one, seems a common issue. 

 

17 minutes ago, SuperbTWM said:

will investigate this weekend but I’m 95% sure it will end up with a new one, seems a common issue. 

Hi, there is no way to fix this in my opinion. Just replace it and you done. The location of the valve will be different on every model I suppose. On my petrol Octavia 1.4 it is on the back of the engine, close to oil drain cap and filter.