[SOLVED] Low oil pressure at idle

[OllieVRS]

Finally got around to draining the oil and doing my inspection, the oil was black of course.


Here a cutout of the filter, which probably didn't even cover 1000km since I changed it:





It may be hard to see on the picture, but there's tiny metal specks here and there. Half were magnetic. Notice there's quite a lot of 'dirt' though.


On the other hand, here's the filter from the previous 5000km, also on the same Miller's:





It has a similar amount of metal fragments, mostly non-magnetic? Or they're just embedded too much in the filter for the magnet to pull them out.

There's a lot less 'dirt' on the filter with much higher mileage. Could this be because the higher track temperatures dislodged dirt and gunk from around the engine? Could some of that dirt and gunk maybe gotten in the pick up pipe, causing the light? Just my theory.


Also as promised, looked with an endoscope looking for loose things that could've potentially blocked the pick up, but I didn't see anything:






Put in the Mobil 1, and took her on an aggressive drive around the neighborhood and then the motorway to try and recreate the conditions it had on track, at high RPMs around bends. Of course it wasn't a true recreation of the track because otherwise I'd be writing this post from a jail cell 

But I'm happy to say the oil pressure light didn't come back.

What are your thoughts on this? Cheers 

[pudding]

Yeah I think the 'dirt' is carbon/sludge dislodging from various points around the engine.  Mine used to do the same.  I could squidge the 'chunks' between my fingers and they were smooth, not crispy, if that makes sense, so I wasn't too concerned.

Is yours a manual?  Little shavings could be the crank thrust bearing wearing out, especially if it has an uprated clutch, or a worn out original that has become heavy.

[OllieVRS]

Yeah I think the 'dirt' is carbon/sludge dislodging from various points around the engine.  Mine used to do the same.  I could squidge the 'chunks' between my fingers and they were smooth, not crispy, if that makes sense, so I wasn't too concerned.

Is yours a manual?  Little shavings could be the crank thrust bearing wearing out, especially if it has an uprated clutch, or a worn out original that has become heavy.

Yeah it's a manual.

I feel the clutch has been replaced in the past, considering the biting point was pretty low down when I first got it when it was at 117k miles. Now it's at 127k miles and the biting points higher than it used to be, but still not too close to the top of the pedal.

I have the clutch stickiness issue, where every now and then the clutch pedal will be hesitant to rebound instantly back up. The car is in gear, but the pedal about half-way up sticks for a split second before continuing to go back up all the way. Twice on the track on it got stuck half way up for about a full second when downshifting from 4th to 3rd, but it was engaged in 3rd gear, just the pedal wasn't up fully. That's the longest it's ever happened.

But in normal driving I'd say it gets stuck (and only for 0.1 seconds) every 50 shifts. I think this is down to a bearing on the gearbox, that you can get a shim kit for. But I'm not too bothered to fix it.

Also for reference of the state of the filter, here's the filter that I originally pulled out when I first got the car haha, it was dreadful:





I'm not sure if I posted the image from my original posts in 2021, but there was a metal 'shard' in the sump, about 12mm in length and 1mm thick. I couldn't identify what it was. There was other crap in the sump like a piece of electrical wire, so I didn't rule it out as an internal engine part that had broken off. It can be seen in this picture in the pool of oil, just below the broken pieces of plastic from the pump chain cover (which is what may have caused the low oil pressure the first time around):




And crank thrust bearing being wrecked means engine out and full rebuild right? So is it time to start thinking of selling her in your opinion, to avoid spending thousands on her again?

[OllieVRS]

I'm back, without a bang. Yet.




Here's a video of the pressure at idle and 2000RPM.

Correct Specs for EA113 TFSI:
Idle 1-1.2 bar or (14.5-17.4 PSI )
2000 RPM 2.7-4.5 bar (39-65 PSI)
3000 RPM 3.5-4.5 Bar (51-65 PSI)


So something's amiss. 2000RPM Pressure is fine, but idle is definitely not. The oil pressure should never be below 1 bar, let alone on a thicker oil like the 0W40 which should be raising the pressure itself by 1 extra psi at idle.

Unlike last time I had low oil pressure, where I accidentally cured it before finding the symptom by dropping the sump before measuring the pressure, this time I haven't changed anything and just went straight to sticking in the pressure gauge.

I'll start off by checking the cam chain cover oil control rings, and the oil channels in the cover too. And then remeasure the pressure. That will likely yield little to no difference, but it's worth checking as I've never taken it off before.

Then I'll drop the sump, replace the pick up pipe and install a VIS balance shaft delete freewheel. Also I'll check the ends of the balance shafts aren't loose, as well as no mounting bolts having have fallen out of the oil pump, like one did last time.

And then fingers crossed, the pressure will be back to normal when everything's been put back together.

[pudding]

That large shard of metal doesn't look good    I think it might be the thrust bearing, especially as you've said clutch pedal return is a bit lazy. It's not a complete rebuild to replace that, but it pretty much is an engine out job though.

Get a pry bar on the crank pulley and lever on it to check the end float. It should only move laterally about 0.5mm at the most.

You would definitely be losing a bit of low rpm oil pressure if the crank and/or thrust washer are breaking up.  Try the gearbox shim kit first but it's not looking good overall with that slither of metal and the shavings in the oil filter 

[OllieVRS]

Got to taking the cam chain cover off, had to improvise to get the bottom T30 put as my normal bit wouldn't fit 




I didn't find anything suspicious, everything looks normal. Tensioner still tensioning. Oil control rings are perfectly intact.







Of note are the cam lobe and cam follower, both of which have a little wear.






The cam follower was replaced 11k miles ago, with FEBI one off Amazon. Keep in mind the last 3k miles have been at sub spec oil pressure, this may have accelerated it's wear. I assume it needs to be replaced?

Contrast this with the one I pulled out 11k miles ago, with an unknown mileage:





 And also the cam lobe 11k miles ago, which doesn't like like it changed much in that distance.




You make a valid point @Pudding . But the metal shard was 11k miles ago, long before the clutch issue. The clutch issue actually began after a failed 3k rpm clutch drop, where I forgot to put the handbrake down. Painful, I know.

I dropped the sump 6 months after the initial drop, and found no more metal shards. So I doubt that's the thrust bearing.


But I gotta drop the sump before jumping to conclusions, as I haven't had the chance to get it jacked up yet. I hope there's a glaring answer in there, waiting for me.


EDIT: FEBI cam follower is €30, while OEM cam follower is a mind boggling €67 from VW 

[pudding]

Ah OK, I thought those pics were the current situation!

67 for a cam follower!!! 

[OllieVRS]

Replaced pick-up pipe (barely anything on it, slight dirt in the sides), installed VIS freewheel, new filter and Mobil 0W-40. No loose objects in sump, just a little dirt. Balance shaft ends weren't loose.

Retested oil pressure, gave engine a good while to warm up, 90 degrees and then another 10min.

Hot idle,  still at 0.8 bar. May have increased by 0.05bar, but it's negligible.




2000rpm: 51psi
3000rpm: 57psi

Both are well within spec.

Video of RPM test:

Also changed out the PCV for the oil one, yielded identical pressure.

What to do next? Is this oil pressure acceptable?

Cheers   

[OllieVRS]

Email from Wasamotor:





I would prefer to definitively find the issue before sinking more money in to iy, and Wasa weren't so helpful with their response in that regard.

How do I check the oil pressure release valve has failed on the oil pump?

EDIT: Found a thread on Audizine, it's a gold mine for information on this exact issue.
https://www.audizine.com/forum/showthread.php/942266-Absolute-Taint-Punch-Low-Oil-Pressure-on-Freshly-Rebuilt-2-0-FSI-Input-Needed

[OllieVRS]

Tested with old oil pressure gauge, identical results.

Interestingly, the oil pressure is at 20 psi at 850rpm when hot. That's a big jump from the 12 psi at 720rpm. Tempted to just raise the idle rpm in VCDS, but I think that's a foolhardy solution.

Compression is still alright, only checked Cylinder 1, first try 175psi, second 160psi. Hot and WOT.

[OllieVRS]

Took the oil pump out, and the pump mechanism to inspect it, as suggested by the WASAmotors engineer I've been emailing. This was in order to check the oil pressure release valve was not stuck open (mine isn't) or there isn't any wear in its bore. It's the brown thing with the ridges.




I tried to get the back of it off to further check, but even with a breaker bar I couldn't.




I sent to first picture to the WASA engineer and he had this to say:




Bashing in my M8 spline with a mallet and using a wobble 1/4" extension I managed to get all three oil squirters/oil jets out, and I took a short video of the condition of their ball-spring valves.

eature=share


As you can see, the first one has very little resistance to pressing it and even gets stuck when pressed down. The second has medium resistance and the third a high resistance. The first one is the most likely cause of the low oil pressure at idle.

Now I know the WASA engineer said the pump is bad. But my oil pressure above idle is absolutely fine, same as it was 11k miles ago, and within VWs oil pressure specification. I've had 5k km oil filter changes with no metal shavings at this oil pressure. I can't justify another ~€300 for another if mine is working sufficiently.

My plan is to replace the three squirters and that's it. Not sure I'll bother with replacement bolts for the oil pump since there's no active balance shaft there anymore to shake them out anyway.

Cheers, hopefully this is helpful to someone 

[pudding]

If those marks at the bottom of the pump housing are gouging, then I think Wasa Motor are right. It certainly doesn't look healthy.

Maybe pick one up from ebay, strip it down and see if it's better than yours?

[OllieVRS]

Little interim update while waiting for the oil squirters.

If those marks at the bottom of the pump housing are gouging, then I think Wasa Motor are right. It certainly doesn't look healthy.

Maybe pick one up from ebay, strip it down and see if it's better than yours?

Took a more serious look at the gouging, as I realised it may have looked pretty serious from the photo I sent.

Gouging as seen from my phone camera:




Gouging as seen from my endoscope camera. Enough to catch a nail, but not as deep as it looks from the previous picture:






PRV bore inspection, doesn't seem worn out. No wiggle room.






And the PRV spring is still intact.





I can't justify a >€300 used oil pump when the oil pump I have seems fine and the pressure it puts out is within spec. I read on the Audizine forum that the PRV is designed to open at 58 PSI anyway to prevent over pressurising, and my oil pump gets up to 58psi at 3k RPM.

We'll also see how the new oil squirters affect the pressure at higher RPMs, I doubt they will, but there's a chance. Here's to hoping. 


Idle pressure is the only one out of spec so that's definitely going to be fixed by this. Here are the three squirters next to each other, spot the odd one out:




Apologies for the photo-heavy post.

[OllieVRS]

I was right. OllieVRS 1-0 WasaMotors Engineer.

Just joking, there was probably some truth to his claim, I'll go into detail later.


So I've fixed the idle oil pressure. After replacing all three accessible oil squirters, the hot idle pressure has been raised from 0.8 bar to 1.2 bar (12psi to 17psi).

The original guidelines from the Audizine forum state that the measurements are at 80 degrees engine oil but I think that's a load of BS so I just let the car idle for 15 more minutes after the coolant hits 90 and then take my measurements.

Measurements before fix:
Idle: 0.8 bar (12psi)
2000: 3.6 bar (52psi)
3000: 3.9 bar (57psi)

Measurements after fix:
Idle: 1.2 bar (17psi)
2000: 3.6 bar (52psi)
3000: 3.9 bar (57psi)

So only the idle pressure has changed after the fix, the other pressure remain identical. Measurements done on 0W40 before and 5W40 after, so difference should be negligible.

Final Hot Idle




Video of Idle-2000-3000rpm

eature=share


Picture of original oil squirter (left) 06F 103 154 A, next to newer revision oil squirter 06F 103 154 C. The only visible difference is that the ball-spring on the newer one has a flat face. Apparently VIN numbers matter when buying these, I asked the guys at Skoda-Parts.com and they confirmed the newer one was the one for my Octavia.




Picture of where the oil squirters are located and how we reached them (the crankshaft has to been turned to a very specific angle for each of the three). We used 1/4" wobble-end extensions and big hex M8 spline bits inside 10mm sockets, and torqued the new ones to 27Nm. A long screwdriver is also required to point the spray jet nozzle in the right direction as you tighten the bolt and to line it up with the flat groove in the block.




My final thoughts are that my pressures are well within spec, but seemed to be capped just under 4 bar (59psi). I think this is due to the spring in the pressure release valve in the oil pump being weaker due to age and poor servicing in the past, so it's opening slightly prematurely. Just 10k miles caused my idle pressure to drop from 18psi to 12psi, basically one of the oil squirters collapsed in that mileage, so I would be anxious that the spring in the PRV could collapse in similar mileage too.

The WasaMotors Engineer pointed out the scratches in the pump mechanism look bad but it's impossible to measure the effect of them on the oil pressure. And that my pump would benefit from their oil pressure fix. Which I would look into were it not for the fact that my pump's PRV bolt seems to be permanently glued shut. Not even a breaker bar could get it open . It must have been already fixed once by a previous owner, and they bodged it.

The scratches would affect the pressure across the board, whereas the PRV would only affect the higher RPM pressure. My 3000RPM pressure only being slightly higher than my 2000RPM pressure would suggest the PRV spring is the main limiting factor.

Ideally I should be able to surpass 4 bar at 3000RPM. I'll remeasure it in a few months to see if the upper pressure limit has degraded any further.



That's all for now. I'm going to work on an oil pressure solution guide for the forum considering how much knowledge I've gained researching this topic, and also from experience. Hopefully that will be of use to a few people

Cheers

[pudding]

Yeah the gouging marks look far less severe in the newer close up pics    Still not ideal, but not as bad as I first thought.

Hmmmm, yeah, definitely evidence of poor maintenance in the past. The very dark staining on the metal castings is a clear indicator of skipped oil changes.

Still, you've persevered and improved the low rpm oil pressure, so go you fella