E46 M3 S54 Vanos pressure tests

[Arinb12]

I have just also noticed something peculiar, didn't happen before I retimed the engine and rebuilt vanos...

When I start my car now after a long drive and when the car is still warm. It still takes the 3 turns of the starter motor, and then ignites. But sometimes the 3rd turn of the starter stutters before the engine starts, sometimes it's nice and smooth, I wonder what that could be and if any impact?

normal start:

https://youtube.com/shorts/4xA2IifkcOo?feature=share

Strange start just before the engine starts properly it can be heard (2/3 seconds):

https://youtu.be/EOrgV3eI7pc

I had a new starter 2000miles ago
also above are my adaptations and fuel trims I assume they could not be causing issue to either the vanos test or the start issue I mention here?

[Santino]

I'd like to also try this, could you please let me know where I can connect the oil pressure guage? Is it under the oil filter housing? Is there a special thread sensor I need?

Santino what did you use?

Is this the location?

On the oil filter housing You have the original oil presssure sensor pictured on the photo above, and a blank screw M12 right next to it, i used that place to screw in the banjo bolt for the gauge

[sapote]

What about the oil regulator valve on the vanos body that is in the centre? Could that also be causing low pressure?

Video of warm oil: the vanos pressure was about 50 bar at idling, and it increased with higher rpm. This means the low P is not caused by regulator but due to not enough supply oil, either from engine pump or the vanos disk pump. Also, during cold oil, the P was about 114 bar so this again proves the regulator is not the problem, but you had adjusted it and now it may not be set correctly.

The leak down seems to be a little fast. This could be due to a near empty ACC.

Yes, measure engine oil pressure then go from here.

[maupineda]

You remove your vanos line and the gauge goes there. Here is a few links to what you will need. Raj (Besain) recommend to use red loctite to seal the gauge/fitting. Buy some vanos line crush washers as well because you will use 4 every time you test/re-install vanos line.

https://www.ebay.com/itm/M10-x-1-0-S...-127635-2958-0



https://www.ebay.com/itm/201L-158O-1...-127632-2357-0


PS: Looks like the gauge my no longer be sold by the same eBay person, look at the specs. Contact Raj at Beisan if you have trouble getting the right gauge.

He is asking about engine oil pressure.

BMW attaches the gage to the filter housing, where the cap bolt is.



Spec

[Cubieman]

I'd like to also try this, could you please let me know where I can connect the oil pressure guage? Is it under the oil filter housing? Is there a special thread sensor I need?

Santino what did you use?

Is this the location?

You remove your vanos line and the gauge goes there. Here is a few links to what you will need. Raj (Besain) recommend to use red loctite to seal the gauge/fitting. Buy some vanos line crush washers as well because you will use 4 every time you test/re-install vanos line.

https://www.ebay.com/itm/M10-x-1-0-Stainless-Steel-20mm-Banjo-Bolt-With-1-8-NPT-Brake-Light-Switch-Port-/361110675174?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=710-127635-2958-0

https://www.ebay.com/itm/201L-158O-1-5-Glycerin-Filled-Stainless-Case-Gauge-1-8-NPT-LM-0-2000-psi-/172993590870?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=711-127632-2357-0

PS: Looks like the gauge my no longer be sold by the same eBay person, look at the specs. Contact Raj at Beisan if you have trouble getting the right gauge.

[Arinb12]

In the meantime, just to be sure a bad ACC is to blame, you can hook up an external oil pressure gauge to the engine oil sensor and check engine oil if it drops when rev up as shown in previous video, for whatever the reasons. It should not drop.

I'd like to also try this, could you please let me know where I can connect the oil pressure guage? Is it under the oil filter housing? Is there a special thread sensor I need?

Santino what did you use?

Is this the location?

[Arinb12]

It is unlikely, the in-feed valve if I recall correctly is preset to 1 bar (which is close to the minimum engine oil pressure at idle) so the VANOS pump uses this oil supply to build up high pressure (115 bar).

I had to do extensive troubleshooting in my car as some specialists sweared the problem was my VANOS, yet it wasn’t, but keep in mind my car is a low miler (43k) at the time of the issue. One OE disc after, my issue was fixed.

in Arinb12 case it seems to be wear and tear, but pls share mileage on the unit if known)

the reality is that an engine with regular oil changes should not see wear in this interface at all as it spins around an oil film. But we know most cars are neglected.

How can I test the engine oil pressure/confirm.

Where is the oil sensor? I heard there is a blank hole there that I can attach a manometer to?

Unit is on 155,000 miles

[maupineda]

What about the oil regulator valve on the vanos body that is in the centre? Could that also be causing low pressure?

It is unlikely, the in-feed valve if I recall correctly is preset to 1 bar (which is close to the minimum engine oil pressure at idle) so the VANOS pump uses this oil supply to build up high pressure (115 bar).

I had to do extensive troubleshooting in my car as some specialists sweared the problem was my VANOS, yet it wasn’t, but keep in mind my car is a low miler (43k) at the time of the issue. One OE disc after, my issue was fixed.

in Arinb12 case it seems to be wear and tear, but pls share mileage on the unit if known)

the reality is that an engine with regular oil changes should not see wear in this interface at all as it spins around an oil film. But we know most cars are neglected.

[maupineda]

I failed the vanos test prior to this due to timing issues at the first part. I decided to rebuild new seals before refitting the vanos after timing. My disc is the original but has been drilled by the previous owner?

Could it have worn out that much that it no longer produces enough pressure??

What part is the pump shaft? And what part of this disc could be worn?

What are my options now?

Unfortunately, it seems your only option is another unit, if you say your disc is original to the car, and you have low pressure, then wear and tear has reached you, what is the mileage on the car? or your re-drilled OE disc is from a high miler.

Your test results confirm you have no timing issues, you passed the leak down test, though the exhaust cam moved a bit more than I would have liked, still, within the 5deg tolerance, DIS is complaining about the timing to adjust (retard). another possibility can be to try another solenoid valve body but based on your pressure at idle, and the fact that DIS tests at 1500rpm, is just trying to find lipstick for the pig.

the sad truth to all this is that changing the disc from one VANOS to another is like moving a rod bearing from one rod to the next, not a good idea.

If you hop into eBay, you can find a spare VANOS and pray is good, or have a disc manufactured to your shaft dimensions, but I think that is more cumbersome than not, I had to spare a whole VANOS unit to get an OE disc off of it.

[Arinb12]

Interesting you are having issues with the original disk. I'm in the process of swapping vanos units because my original is not producing enough pressure at all with a besian redrilled disk oe disk from years ago. I have been told the tolerances of all these components can get looser as the mileage rises so it's possible. I picked up a 60k mile unit and had dr vanos drill the holes on the same disk I sent out. My car also has a brand new genuine bmw oil pump, chains, and guides so if that doesn't get me back to spec something is wrong lol.

You also could have a bad regulating valve on the solenoid body. If that doesn't fix it, get an entire vanos unit with the same oil pump disk and just change everything.

What about the oil regulator valve on the vanos body that is in the centre? Could that also be causing low pressure?

[Arinb12]

Low mileage ones are like gold dust in the UK unfortunately!

[thegenius46m]

I failed the vanos test prior to this due to timing issues at the first part. I decided to rebuild new seals before refitting the vanos after timing. My disc is the original but has been drilled by the previous owner?

Could it have worn out that much that it no longer produces enough pressure??

What part is the pump shaft? And what part of this disc could be worn?

What are my options now?

Interesting you are having issues with the original disk. I'm in the process of swapping vanos units because my original is not producing enough pressure at all with a besian redrilled disk oe disk from years ago. I have been told the tolerances of all these components can get looser as the mileage rises so it's possible. I picked up a 60k mile unit and had dr vanos drill the holes on the same disk I sent out. My car also has a brand new genuine bmw oil pump, chains, and guides so if that doesn't get me back to spec something is wrong lol.

You also could have a bad regulating valve on the solenoid body. If that doesn't fix it, get an entire vanos unit with the same oil pump disk and just change everything.

[Arinb12]

I failed the vanos test prior to this due to timing issues at the first part. I decided to rebuild new seals before refitting the vanos after timing. My disc is the original but has been drilled by the previous owner?

Could it have worn out that much that it no longer produces enough pressure??

What part is the pump shaft? And what part of this disc could be worn?

What are my options now?

[maupineda]

Your problem is not the accumulator nor the regulating valve, but your VANOS pump, which once the oil is warm, does not generate pressure. this is due to either a worn-out pump shaft, a worn-out disc, or incorrect tolerances of the radial pistons.

I had the same problem, in my case, the issue was the pump disc, I had to source another OE disc, have it redrilled, and the problem was solved.

to anyone doing VANOS work, I now advise to always measure pressure BEFORE as well as run a DIS/ISTA test, and if all is ok, leave it alone. if you feel you need to fix the play with the exhaust tab, then just make sure you redrill the original to your car disc.

I am more than sure this issue with the disc is present in many cars, just people do not test for it, also, low pressure does not necessarily mean the VANOS test will fail as when the rpms rise the pressure rise to a point where there is enough of it to actuate the VANOS splines. however, it is pretty upsetting to know you have a non-confirming system LOL

in your case, your VANOS does fail as the pressure is too low and causes the response times to be too slow.

EDIT: on the Z4M VANOS test is done at 2k rpms, on the E46 M3 is done at 1500 rpms, so it is more sensitive to low pressure as at 1500 there will be less pressure if your pump fails to be at 115 bars at idle.

[Arinb12]

Edited to remove