OIL PRESSURE 10PSI HELP!!

[GTI-MK5-APR2+]

Hello,



I have a GTI MK5 2008 FSI APR 2+



I have a problem with low oil pressure and im already quite exhausted with this problem.



Earlier in a long story the low oil pressure light started to come on and well... you know..



After removing the crankcase we realized that the balance was seized.


I got locally a used original oil pump from a ¨tested¨ audi FSI, the pump looked good overall, we changed the chain, tensioner, the pump and a couple of months before we had changed the oil filter housing(FEBI).



I put a digital oil pressure gauge in my cabin to measure pressure while driving.



And this is where the problem comes...



The pressure in the car as soon as i started it was 61psi, everything was fine... as the oil warmed up it went down.. as is common...



The problem is that it drops to 10psi i when hot after pressing the accelerator hard... it doesnt go up or down more than 10psi at idle (740rpm)



When it comes to accelerating everithing is fine.. at 2k rpm 41psi when hot... the problem is at idle..

[OllieVRS]

Hi, I had a similar problem a couple months ago. Oil pressure was fine a 2k and 3k RPM hot, but not idle. If you have low oil pressure only at idle specifically, it can only be caused by two things: 1. Oil Spray Jets (more likely) 2. Oil Pump Pressure Release Valve (PRV) (less likely)

Both of these are supposed to only open at higher oil pressures, a.k.a higher RPMS. The Oil Spray Jets are for cooling the undersides of the pistons, which don't really need cooling at low RPM so they should closed. The PRV is one of the mechanisms to stop the oil over-pressurising, and should open at 59psi if I recall correctly.

With your oil pressure starting off at 61 psi cold idle (meaning your PRV is correctly opening, mine has always had 55psi), I assume that that's unlikely the problem. Could you also tell us your oil pressure at 3k RPM hot? It should be nearly or the same PSI as your cold idle PSI.

What's also weird is your 2k RPM psi is slightly low, most people have above 50psi at 2k. I'm not sure why that is. But at least it's within spec.


As for idle, I used to have a 12psi at idle, and idle should always be above 14.5psi (1 BAR). After replacing the pickup, double checking there was no wiggle in the end of the oil pump balance shafts, and checking PRV spring was still intact (with a endoscope, you can check my post here) I narrowed it down to the Oil Spray Jets.

Without removing the crankshaft, and using wobble extension bars, you can get 3/4 of them out. One of mine's ball-spring mechanism has completely collapsed, just staying open from gravity. The other two had some resistance, but not very much. I replaced all 3 anyway.


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)


Of course, if your PRV is stuck open at all times then oil pressure will be low across the board, which is why I included it, although unlikey. If your 3k pressure is below 50psi then I'd say it's probably the PRV, which is not an OEM replaceable part. WasaMotors sell a fix for that, but you need to be quite handy with a drill, and risk getting metal fillings inside your oil pump mechanisms. Or you can get another used oil pump, but those are luck of the draw. Also look at my post, I checked for metal gouging in the pump rotor mechanism, I recommend you do the same. Mine was still acceptable, even with scratches.

One more thing, you say you're using a digital oil pressure gauge. These can be a little inaccurate, so I suggest hooking up a mechanical oil pressure gauge tool first to confirm you're getting the same results as on the digital gauge.

Hope that helps, let me know if there's anything else you want to know about your psi numbers, I'll be happy the analyse them for you. 

[GTI-MK5-APR2+]

hello @OllieVRS

thanks for your answer.

I have been reading your forum and I would bet that the sprayers are also the problem with my car.

After changing the oil pump, we used a mechanical pressure gauge to start the car and see the oil pressure. We saw the same thing as when we put the digital pressure gauge on to test the oil pressure a couple of days on the street, this happened this week.

Yesterday afternoon I went out to record various scenarios, from the cold start, to the worst moment (17 minutes after ignition rolling down the street).

You tell me what you think. 

Cold Start:

eature=share

Oil pressure 6min:

eature=share

Oil pressure 9min:

eature=share

Oil pressure 17min:

eature=share

[OllieVRS]

Your 3k RPM pressure is perfect, 2k is slightly low but within spec. 1k obviously too low, I'm surprised it's not rattling with such low idle oil pressure.

I can say with 75% certainty that it's the Oil Spray Jets rather than the PRV. One thing I didn't mention in my previous post is that the PRV's bore can wear out leading to a general loss in pressure at mid-low RPM, read about that here.

The difference with your psi and mine is that I was hitting 20 psi before I even got to 1k RPM. So that pretty much guaranteed for me it was the jets. But with yours the pressure increases gradually, making me more uncertain.

Replacing the jets is cheaper albeit more difficult than the oil pump (or the pumps PRV) so I'd recommend going for that first. There's not really any online tutorials for this, so here's how I went about it. Once you've removed the oil pump, have a read of this:

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.

Careful you get the optimal angle while doing this, it's possible to strip their heads if you go in crooked. You will have to rotate the crankshaft back and forth for that optimal angle^

Unfortunately once you take them out your have to replace them, so I'd recommend ordering them ahead of time. In Ireland they cost me €25 each from my local VW dealership. You will only need 3, as the 4th is not accessible because of the crankshaft's timing wheel. But replacing 3 should be enough to raise the oil pressure to sufficient levels at idle, if they are the cause.

I hate to say this too, but in case you don't know you will need replacement oil pump bolts as they're all stretch bolts:
(Irish prices before VAT included)
1x WHT 000 360 B        long barstewards 13
3x N  911 495 01           2.26
4x WHT 000 006           2.10
1x N  911 496 01           2.20
1x N  104 305 02           5.13

All of these are 15Nm + 90 degrees.

(I'd recommend taking pictures and noting which length of bolt goes where as you take them out, but if you're replaced the pump before I'm sure you know what you're doing).

1x N  903 659 01  Oil Pump Sprocket (Not Balance Shaft) Bolt                1
20Nm + 90 degrees.

Also, there are two separate part #s for the oil spray jets: 06F103154A (From VIN 8E-7-088 001) and 06F103154C (Up to VIN 8E-7-088 000). They look exactly the same but are different in price. I would recommend contacting VW or skodaparts.com’s support for assurance. Give them your VIN, and they’ll tell you.

Just 27Nm for the spray jets.


In your place that's what I'd do first. Unfortunately there's no way to inspect them externally, or knowing for certain what's causing the insufficient pressure. And even with the oil pump taken out it can be very difficult to inspect the PRV. For example, the wide hex bolt holding my PRV seemed to be permanently shut, so I couldn't open it to inspect it externally, so I took the rotor mechanism apart to inspect it the best I could from there.

Be prepared to empty your pockets once more is all I can say. And be very patient getting those spray jets out, if you strip those heads you may be unable to get them out.

Good luck.

[OllieVRS]

Hey @GTI-MK5-APR2+ , any update on the situation? I'm rooting for you 

[pudding]

You've done the community a solid with the oil jets Ollie.  I always thought the idle oil pressure is sh1t on these engines, and you found the primary cause, in older engines at least 

I don't really know why the oil flow is so poor at low revs on these engines. Historically they've always been plagued with lubrication woes, dating back to 2004/5 engines with shearing off oil pump drive sprockets (which were recalled under warranty), to seized balance shaft bearings, thru blocked pick ups and everything in between.

My old 1.8T VWs and my VR6 and my R32 gave 2 bar hot idle pressure minimum.  1 bar or less on the TFSI is just pathetic really, but hey ho, it is what it is.

[OllieVRS]

You've done the community a solid with the oil jets Ollie.  I always thought the idle oil pressure is sh1t on these engines, and you found the primary cause, in older engines at least 

I don't really know why the oil flow is so poor at low revs on these engines. Historically they've always been plagued with lubrication woes, dating back to 2004/5 engines with shearing off oil pump drive sprockets (which were recalled under warranty), to seized balance shaft bearings, thru blocked pick ups and everything in between.

My old 1.8T VWs and my VR6 and my R32 gave 2 bar hot idle pressure minimum.  1 bar or less on the TFSI is just pathetic really, but hey ho, it is what it is.

Always happy to help, if it means I can at least save one more tfsi from the scrap yard.

I don't want to claim credit for finding the oil spray jet problem, that's largely thanks to other forums like a post on Audizine. There's a video towards the bottom of the guy showing how his oil spray jets failed, and to my knowledge this is the only video on the internet that does an in depth analysis of them (for our engine specifically).

All I've done is spent an unhealthy amount of time researching and overthinking, trawling American, Polish and even Russian VW forums, and then neatly presenting my findings here. One of my 'eureka' moments was on that Polish forum where on one post some guys were discussing the A6 and its 170hp tfsi, which shares the same spray jets, and then describing oil pressure figures that nearly identically matched mine, before they changed the spray jets and their idle pressure shot right up.. Unfortunately I can no longer find that post.

But I will admit, I do now know a thing or two about oil pressure so I'm always happy to help out if someone on the forum needs it 

[pudding]

It's all good. I never would have considered the oil jets as a cause. Anything hidden in the bowels of the engine is often over looked, but it totally makes sense if the spring and ball valve inside them is knackered, then they'll bleed off pressure at idle