Low Oil Pressure Switch Location

[TheClient]

6 minutes ago, J.R. said:

 

 

It makes me wonder if the previous owner was faced with a similar diagnosis and quote?

 

I have bought cheap many cars with problems that I have eventually resolved by determination and a lot of mental effort, in every case they had been sold on and on making their way through the trade to private owners and back again a few times before they ended up with me, the cheap buyer of expensive problems!

 

I have seen some misdiagnosis and scary quotes in my time all of which missed the actual fault caused by the servicing dealers incompetence but £9K for a missing O ring if that is the case here takes it to a new level, its 100% believable sadly and I really hope that it is the case for the OP.

 

It is worth hoping - but no guarantees!!

 

@vRSRutty

 

The other thing I'd also try either myself or talking through with the tech, which surely the garage will have tried,  is to disconnect the connector the the N428 oil pressure control solenoid. Observe behaviour.

 

It'll probably create another engine fault - no oil pressure regulation or something but...

 

From my reading of the self study guide, this de-energised state should then run the pump at maximum pressure at all engine speeds. With a gauge plugged in, does the oil pressure still drop or fluctuate to low levels?  If not, it would be one reason to suspect the pump maybe at fault in low pressure mode only.. As if I recall the oil pressure warning were, originally, and possibly still  all on reduced oil pressure sensor and operation...... 

 

[vRSRutty]

22 minutes ago, J.R. said:

 

 

It makes me wonder if the previous owner was faced with a similar diagnosis and quote?

 

I have bought cheap many cars with problems that I have eventually resolved by determination and a lot of mental effort, in every case they had been sold on and on making their way through the trade to private owners and back again a few times before they ended up with me, the cheap buyer of expensive problems!

 

I have seen some misdiagnosis and scary quotes in my time all of which missed the actual fault caused by the servicing dealers incompetence but £9K for a missing O ring if that is the case here takes it to a new level, its 100% believable sadly and I really hope that it is the case for the OP.

Potentially, I'm surprised it's survived this long knowing what I now know.

 

Will have to see how the next week pans out.

11 minutes ago, TheClient said:

 

It is worth hoping - but no guarantees!!

 

@vRSRutty

 

The other thing I'd also try either myself or talking through with the tech, which surely the garage will have tried,  is to disconnect the connector the the N428 oil pressure control solenoid. Observe behaviour.

 

It'll probably create another engine fault - no oil pressure regulation or something but...

 

From my reading of the self study guide, this de-energised state should then run the pump at maximum pressure at all engine speeds. With a gauge plugged in, does the oil pressure still drop or fluctuate to low levels?  If not, it would be one reason to suspect the pump maybe at fault in low pressure mode only.. As if I recall the oil pressure warning were, originally, and possibly still  all on reduced oil pressure sensor and operation...... 

 

 

I'll pass this on to the mechanic who I'm taking it to next week, he seems more open to the idea of just stripping it and seeing if he can find anything.

[J.R.]

It will be very interesting and I hope rewarding to hear the news.

[J.R.]

A question for @TheClient

 

Having read through the first page again and understanding more about the dual pressure oil pump and the piston cooling circuit could another possibility be that the solenoid valve for the piston cooling circuit is stuck open and hence there is too much pressure drop during the lower pressure output?

 

The extracts from the self study guide spoke about reduced oil pump speed, that would concur with the above suggestion if its the pump speed that is reduced rather than its output pressure via a PRV but how do they acheive different gearing to the pump? It doesn't explain how and the front mounted one looks to be driven from the poly-V accessory drive belt.

[TheClient]

2 minutes ago, J.R. said:

A question for @TheClient

 

Having read through the first page again and understanding more about the dual pressure oil pump and the piston cooling circuit could another possibility be that the solenoid valve for the piston cooling circuit is stuck open and hence there is too much pressure drop during the lower pressure output?

 

The extracts from the self study guide spoke about reduced oil pump speed, that would concur with the above suggestion if its the pump speed that is reduced rather than its output pressure via a PRV but how do they acheive different gearing to the pump? It doesn't explain how and the front mounted one looks to be driven from the poly-V accessory drive belt.

 

It's a possibility. But my understanding is it should report and engine dtc if there is cooling jet oil pressure when the engine ecu has not asked for it. One of the reasons the cooling jet oil circuit has its own oil pressure switch. Both positively and negatively monitored /  checked by ecu. 

 

The dual speed pump is achieved apparently by a sliding gear internally that either meshes with another gear or doesn't based on solenoid control. I'll see if I can find a good excerpt the self study guide referred to explanation in tge ea211 1.4 litre engines as a full explanation  is in that guide apparently.

 

I've never seen one or pulled one apart. 

 

I'll see what I can find to post here. 

[J.R.]

If I were at my main residence where I have a printer I would have printed out the self study guide as bedtime reading, these vehicles are getting so complicated that we need to bone up and have knowledge if not experience in advance of being faced with our first new problems.

[vRSRutty]

Update on this! @J.R. @Breezy_Pete @TheClient

 

The garage didn't check why or how the car has low oil pressure.

 

Didn't check the sump, oil pump, pick-up pipe, PCV valve, nada. 

 

They said even IF it was any of them, chances are the damage is already done.

 

Just told me it has low pressure and quoted me £8800 for a brand new engine.

 

Is it true that the damage will be already done? It was running at 0.4 bar, and then when accelerating it spikes up and then drops off, a friend of mine told me that an engine running at that low of pressure is probably knackered. 

Edited 25 November, 2023 by vRSRutty

[TheClient]

35 minutes ago, vRSRutty said:

Update on this! @J.R. @Breezy_Pete @TheClient

 

The garage didn't check why or how the car has low oil pressure.

 

Didn't check the sump, oil pump, pick-up pipe, PCV valve, nada. 

 

They said even IF it was any of them, chances are the damage is already done.

 

Just told me it has low pressure and quoted me £8800 for a brand new engine.

 

So there's some hope...

Wow,  that does leave some hope to check out the things you'd normally check before condemning a £9k engine!

 

It sounds like the garage next week can do some proper investigation and they're at least open to it and up to it.  They may want the car for a longer period of time to fit it between jobs, test over time. If they do - I suggest you persevere and work with them.

 

Of course, reality is you will probably be paying money to investigate - but that is just the way life works most of the time. Clearly, the  garage who says this edit (said the engine is toast without investigation), is so busy and profitable with the day to day routine stuff they can pump through and turnover quickly,  they're not interested in doing the more difficult stuff. To be fair, the less straight forward stuff does take up time and can lead to difficulties and headache when the end result is still a irrepairable engine - but it is part of the job and remit of a full service garage... As long as you take the customer with the journey and give them the options to continue investigation or abandon and realistic that after investigation there are not always guarantees it can be fixed.....

 

I'm still living in hope for you and of course very interested in outcomes.

 

What also seems to provides me a further glimmer of hope is the intermittent fluctuation of pressure reported - specifically during the reduce oil pressure mode. If it were a worn bearing problem causing large clearances I would think the problem would be consistent at a certain rpm i.e. low and out of spec pressure and repeatable all the time at low to mid rpms.

 

If it's dropping suddenly way out of spec sometimes - but not all the time - that also points me to the fact that there is something specific that is sometimes causing it to drop and go out of spec and more than likely "could be" fixable....with oil supply circuits and related bits being the focus which is what you seem to have agreed with the other garage set up to investigate.

 

Don't forget to pull that filter adaptor valve out and have a look. Or get new iinvestigaitng garage to.

 

You shouldn't need a new o-ring for the cannister cover, as it is very new and should have not been compressed too much in short time. Just check it after refitting and running. 

Edited 25 November, 2023 by TheClient

[TheClient]

For the benfefit of anyone interested and particuarly @J.R.attached are 2 x pdfs.

 

1 is the ea888 section on oil supply circuits 

the other is the 2 stage pump section out of the ea211 self study

which has a bit more depth on the pump operation than the ea888gen3 guide.

EA211 VW Self Study 2 stage pump.pdf VW Self Study EA888gen3 Oil supply.pdf

[vRSRutty]

56 minutes ago, TheClient said:

Wow,  that does leave some hope to check out the things you'd normally check before condemning a £9k engine!

 

It sounds like the garage next week can do some proper investigation and they're at least open to it and up to it.  They may want the car for a longer period of time to fit it between jobs, test over time. If they do - I suggest you persevere and work with them.

 

Of course, reality is you will probably be paying money to investigate - but that is just the way life works most of the time. Clearly, the  garage who says this edit (said the engine is toast without investigation), is so busy and profitable with the day to day routine stuff they can pump through and turnover quickly,  they're not interested in doing the more difficult stuff. To be fair, the less straight forward stuff does take up time and can lead to difficulties and headache when the end result is still a irrepairable engine - but it is part of the job and remit of a full service garage... As long as you take the customer with the journey and give them the options to continue investigation or abandon and realistic that after investigation there are not always guarantees it can be fixed.....

 

I'm still living in hope for you and of course very interested in outcomes.

 

What also seems to provides me a further glimmer of hope is the intermittent fluctuation of pressure reported - specifically during the reduce oil pressure mode. If it were a worn bearing problem causing large clearances I would think the problem would be consistent at a certain rpm i.e. low and out of spec pressure and repeatable all the time at low to mid rpms.

 

If it's dropping suddenly way out of spec sometimes - but not all the time - that also points me to the fact that there is something specific that is sometimes causing it to drop and go out of spec and more than likely "could be" fixable....with oil supply circuits and related bits being the focus which is what you seem to have agreed with the other garage set up to investigate.

 

Don't forget to pull that filter adaptor valve out and have a look. Or get new iinvestigaitng garage to.

 

You shouldn't need a new o-ring for the cannister cover, as it is very new and should have not been compressed too much in short time. Just check it after refitting and running. 

 

Yeah, the only thing that unsettled me slightly is that the garage and my friend have both said an engine running at that low of pressure, is probably screwed.

 

Especially as this issue has been happening for a good few weeks, if not a good couple of months now.

 

Do I spend to investigate and then replace (potentially) a faulty part, for it to then be too far gone anyway?

 

Torn between selling it on and cutting my losses, or having faith and spending more money and time with it to be potentially too far gone.

[TheClient]

22 minutes ago, vRSRutty said:

 

Yeah, the only thing that unsettled me slightly is that the garage and my friend have both said an engine running at that low of pressure, is probably screwed.

 

Especially as this issue has been happening for a good few weeks, if not a good couple of months now.

 

Do I spend to investigate and then replace (potentially) a faulty part, for it to then be too far gone anyway?

 

Torn between selling it on and cutting my losses, or having faith and spending more money and time with it to be potentially too far gone.

Yeah. The overhead gear and camshaft and so on would probably suffer first. How does it sound?

 

The new garage may offer guidance once they’ve had a chance to assess a few things. A lot may depend on how sustained this genuine lack of oil pressure is. I.e. is it a few seconds or once it has started,  is it sustained low pressure for minutes…That would probably give some feel for likelihood of consequential damage. 

[vRSRutty]

14 minutes ago, TheClient said:

Yeah. The overhead gear and camshaft and so on would probably suffer first. How does it sound?

 

The new garage may offer guidance once they’ve had a chance to assess a few things. A lot may depend on how sustained this genuine lack of oil pressure is. I.e. is it a few seconds or once it has started,  is it sustained low pressure for minutes…That would probably give some feel for likelihood of consequential damage. 

 

It sounds fine, and yeah makes sense, it's just incredibly out of range, is meant to be 0.85-1.6 and operates at 0.4 lol.

[J.R.]

An engine that is screwed is audible from a mile off to a deaf man.

 

You say the engine is operating at 0.4 bar oil pressure but you only have the word of the main stealer for that, do not take anything anyone in the motor trade is telling you as a given without confirming it yourself, especially when they are hoping for a £9K payday.

 

Checking the drained oil and the removed filter will tell you all you need to know about possible engine damage.

 

Check the O rings on the filter stick while you are at it!

Edited 25 November, 2023 by J.R.

[J.R.]

This makes no sense to me:

 

The two oil pressure switches are monitored by the ECM.
If the oil pressure exceeds a certain threshold, the ECM
opens the correct oil pressure switch. This action transmits
a message across the CAN-Bus, lighting the K3 Oil Pressure
Indicator Lamp in the instrument cluster

 

Should it not read "If the oil pressure exceeds a certain threshold the ECM it
opens the correct relevant oil pressure switch.

[J.R.]

"The piston cooling jets can be activated in either the high or low pressure stage of the oil circuit. An additional oil pressure
switch (F447 Oil Pressure Switch, Level 3) detects the oil pressure in the additional oil gallery and monitors the functioning of the
piston cooling. The oil pressure switch closes at an oil pressure of 0.30- 0.6 bar."

 

I bet that gallery was where they tapped into with their oil pressure guage if they actually did test anything that is rather than just make up a story.

[vRSRutty]

35 minutes ago, J.R. said:

An engine that is screwed is audible from a mile off to a deaf man.

 

You say the engine is operating at 0.4 bar oil pressure but you only have the word of the main stealer for that, do not take anything anyone in the motor trade is telling you as a given without confirming it yourself, especially when they are hoping for a £9K payday.

 

Checking the drained oil and the removed filter will tell you all you need to know about possible engine damage.

 

Check the O rings on the filter stick while you are at it!

 

Will be looking into it over the next few days, but yeah. I'll be checking out the oil filter and tensioner first, just to rule that out, and then I'll probably leave dropping the sump etc to the garage on Thursday - depending on how adventurous I'm feeling.

 

It wasn't a main dealer but rather a reputable garage who fixes the dealership cars for VW etc.

 

and potentially, but that Level 3 switch is an ass to get to without dismantling the air box and removing some sort of wiring guard/pipe, as I tried changing it myself following the manual but couldn't get access to it. Not saying they didn't do this, but I presumed they just tapped in to either sensor at the top as they're so much easier to access.

 

I don't think it was a case of it's totally ruined, but if I were to get it repaired, chances are it'll be too damaged already and would greatly reduce the lifespan.

Edited 25 November, 2023 by vRSRutty

[J.R.]

You would get a very audible warning from the top end as the hydraulic tappets compress long if there was low oil pressure long before any engine damage.

 

An exception would be if  you lose oil pressure on the track at full throttle and 6000 rpm on a long fast corner but for a road vehicle driven normally by someone who is in touch with their engine like yourself there really is nothing to be worried about unless you rag the car to within an inch of its life most times you drive it.

 

Many maybe even most drivers simply ignore any warning lights and they are usually the ones that end up with damaged engines. Deservedly so.

[vRSRutty]

7 minutes ago, J.R. said:

You would get a very audible warning from the top end as the hydraulic tappets compress long if there was low oil pressure long before any engine damage.

 

An exception would be if  you lose oil pressure on the track at full throttle and 6000 rpm on a long fast corner but for a road vehicle driven normally by someone who is in touch with their engine like yourself there really is nothing to be worried about unless you rag the car to within an inch of its life most times you drive it.

 

Many maybe even most drivers simply ignore any warning lights and they are usually the ones that end up with damaged engines. Deservedly so.

 

To be honest, it's barely given me the chance to be able to properly take it out. Whether it was abused by previous owners, I don't know, but that's a chance I'll have to take if I choose to go ahead with getting it fixed.

 

I have some hope knowing that the garage didn't actually check anything, so will see what Thursday brings.

 

I'll keep the space updated and once again thanks to everyone who has offered their help.

Edited 25 November, 2023 by vRSRutty

[TheClient]

36 minutes ago, J.R. said:

This makes no sense to me:

 

The two oil pressure switches are monitored by the ECM.
If the oil pressure exceeds a certain threshold, the ECM
opens the correct oil pressure switch. This action transmits
a message across the CAN-Bus, lighting the K3 Oil Pressure
Indicator Lamp in the instrument cluster

 

Should it not read "If the oil pressure exceeds a certain threshold the ECM it
opens the correct relevant oil pressure switch.

Yes, I think so. The expressions are not perfect in the self study guide. I think they've been  translated from another language, probably German and maybe without editing afterwards. So with some logic throughout, you need to be careful of the logic stated. The content where operation is described are generally better expressed but explicit logic can be revered. So care is needed for sure  

[J.R.]

They are getting far too complicated for my liking.

 

I appreciate that its all these tiny incremental things that give the overall improvements in economy and emissions but we are so far away now from the simplicity and reliability of a basic diesel engine, the numerous sensors and actuators are not to me worth the problems they can bring.

[vRSRutty]

Found this on Facebook, the original poster stated the issue I'd been having, tried changing sensors but no fix, this was one of the replies.

 

[TheClient]

Interesting. I think you  need to start at first base with new garage. Do not assume anything the previous garage said is confirmed and move from there..   

 

A check of oil pressure with a guage into one of the two pressure switch threads on the oil filter housing would be a good start.

 

Checking the oil filter adaptor rod another early test. 

 

The N428 unplugged will force the pump into normal power mode all the time. I mentioned that in an earlier post - but there are quite a few posts.

 

If you're concerned about emgine damage the sump off will help with establishing if that's likely, plus allows pick up strainer to be inspected and cleared. 

 

One point of difference in posts,  is your previous garage says that pressure shows 0.4bar but this post suggests no real oil pressure problem. But I don't know whether to believe your previous garage or where or how they took such a reading.

 

I don't really understand the significance of the power feed relay for the n428 shared with ecu. That sounds pretty normal to me. Almost all engine sensors,,solenoids, actuators are powered off the ecu directly anyway even the electronic thermostat.  Not sure I understand what they were getting at!  But still provides some positive hope. 

[vRSRutty]

42 minutes ago, TheClient said:

Interesting. I think you  need to start at first base with new garage. Do not assume anything the previous garage said is confirmed and move from there..   

 

A check of oil pressure with a guage into one of the two pressure switch threads on the oil filter housing would be a good start.

 

Checking the oil filter adaptor rod another early test. 

 

The N428 unplugged will force the pump into normal power mode all the time. I mentioned that in an earlier post - but there are quite a few posts.

 

If you're concerned about emgine damage the sump off will help with establishing if that's likely, plus allows pick up strainer to be inspected and cleared. 

 

One point of difference in posts,  is your previous garage says that pressure shows 0.4bar but this post suggests no real oil pressure problem. But I don't know whether to believe your previous garage or where or how they took such a reading.

 

I don't really understand the significance of the power feed relay for the n428 shared with ecu. That sounds pretty normal to me. Almost all engine sensors,,solenoids, actuators are powered off the ecu directly anyway even the electronic thermostat.  Not sure I understand what they were getting at!  But still provides some positive hope. 

 

Hmm okay, thanks.

[TheClient]

Very surprising how many threads there are on other forums for mk7 gtis, golf Rs and the like that use ea888 gen3s that talk about low oil pressure warning and then discussion and no outcome.  Makes me worry a bit. They also seem to reside around idle oil pressure in reduced pressure mode..... There are a few related to the piston cooling jet solenoid as that will cause limp mode too but will record a different fault... Anyways

 

On the positive side of the coin, this thread posts closure and turned out to be wiring only to the connector despite replacing the switch and the oil filter cannister and rod along the way.... Worth checking the obvious, i.e. wiring especially with malfunction descriptions on the fault codes for the reduced pressure sensor. Or is it actually saying low oil pressure now? It was not initially...

 

https://www.golfmk7.com/forums/index.php?threads/low-oil-pressure-warning-p164d.365195/

 

[vRSRutty]

12 minutes ago, TheClient said:

Very surprising how many threads there are on other forums for mk7 gtis, golf Rs and the like that use ea888 gen3s that talk about low oil pressure warning and then discussion and no outcome.  Makes me worry a bit. They also seem to reside around idle oil pressure in reduced pressure mode..... There are a few related to the piston cooling jet solenoid as that will cause limp mode too but will record a different fault... Anyways

 

On the positive side of the coin, this thread posts closure and turned out to be wiring only to the connector despite replacing the switch and the oil filter cannister and rod along the way.... Worth checking the obvious, i.e. wiring especially with malfunction descriptions on the fault codes for the reduced pressure sensor. Or is it actually saying low oil pressure now? It was not initially...

 

https://www.golfmk7.com/forums/index.php?threads/low-oil-pressure-warning-p164d.365195/

 

 

According to the garage, it's actually low pressure, it was tested with a mechanical gauge which I presume bypassed and electrics, specifically the oil pressure switch.