Failed vanos test post Beisan

[Cubieman]

* loose pistons in disc side larger holes causing leaky pump.
* tight piston in disc side small holes and cannot moving fast enough.
* new solenoid plate leaking (don't know if it has old or new plate)
* VANOS 2 pistons new seals were twisted when installed causing leak around the seal?

New plate seals were installed and I definitely took my time with installing the main vanos piston seals, although I still may have made a mistake.

So the seals around the 2 vanos pistons have a direct effect on amount of oil pressure produced when measured at the vanos line?

If 100bar is the benchmark then something is seriously wrong here.
I understand it won't be bang on 100bar as the vanos unit has some miles on it (67K), but 60% down is quite substantial.

EDIT:
I recently had an exchange over eBay with a person who rebuilds vanos units and also has a shop that focuses on S54/S62/S85 vehicles, they told me that the pump disc would be item 8 or 9 on a list when troubleshooting a low pressure vanos unit. I am trying to fully understand how this system builds, and more importantly, HOLDS its pressure.

Thanks guys, you have been more than helpful.

[Shonky]

If the solenoid plate was leaking wouldn't that result in an external leak (if anything)? How would that result in low pressure?

[sapote]

What other parts could cause this low pressure if not the disc?

* loose pistons in disc side larger holes causing leaky pump.
* tight piston in disc side small holes and cannot moving fast enough.
* new solenoid plate leaking (don't know if it has old or new plate)
* VANOS 2 pistons new seals were twisted when installed causing leak around the seal?

[Cubieman]

1) On your old parts: VANOS response was in 200ms-ish and it's hard to believe that this great response was with 40 bar or lower pumped pressure.
2) "I talked to Raj over the phone and he is pretty confident that my low oil pressure is due to the oil pump disc shaft wearing." This is easy to verify by rocking the disc on the shaft and feel any plays. Without the original stock disc, it's hard to say they plays is due to worn shaft or new disc has too large center hole.
3) "disc having tighter tolerances in regards to pump cylinders." tighter side holes could also mean slower moving pistons on the intake cycles and this would lower the pump efficiency. If you have one or 2 cylinders with slower pistons moving, then the efficiently is halved as in your case.
4) As rpm is increased, the pump pressure is proportionally increased. This means the pressure relief valve is OK but the pump efficiency is low and needs to be running at higher rpm or higher pressure.

You can wait to see if things get better at 200 miles or remove the the VANOS and check the disc/shaft clearance and pistons motion.

Yea, the low oil pressure isn't going to increase, it is what it is. I suppose if the pistons were sticking and had to "wear in" to their new tighter fit holes then maybe the pressure would increase over time.
I am unsure what to think about this as Raj doesn't seem to think that the new disc would do anything but increase pressure.

At the point I take the vanos off I want new/different parts to install.

What other parts could cause this low pressure if not the disc?

[sapote]

Cold start was right at 100bar, it was slightly higher than 100bar for a brief time period before the vehicle went into closed loop and the idle dropped.
It then got down to 40 bar when up to temperature, wow that's low.
I talked to Raj over the phone and he is pretty confident that my low oil pressure is due to the oil pump disc shaft wearing.
I did not take a pressure reading before disassembly so I cannot say if this is the case or not.
Raj is of the opinion that my oil pressure was the same or likely worse before the new pump disc was installed due to his disc having tighter tolerances in regards to pump cylinders.
He thinks my worse vanos response times are due to the new seals having to get set. He thinks my response times will improve by 200 city miles. I am at about 125 city miles post install at this point.
At 1500RPM (DIS test RPM) gauge read approximately 78 bar.
At 2000RPM gauge read about 82 bar

1) On your old parts: VANOS response was in 200ms-ish and it's hard to believe that this great response was with 40 bar or lower pumped pressure.
2) "I talked to Raj over the phone and he is pretty confident that my low oil pressure is due to the oil pump disc shaft wearing." This is easy to verify by rocking the disc on the shaft and feel any plays. Without the original stock disc, it's hard to say they plays is due to worn shaft or new disc has too large center hole.
3) "disc having tighter tolerances in regards to pump cylinders." tighter side holes could also mean slower moving pistons on the intake cycles and this would lower the pump efficiency. If you have one or 2 cylinders with slower pistons moving, then the efficiently is halved as in your case.
4) As rpm is increased, the pump pressure is proportionally increased. This means the pressure relief valve is OK but the pump efficiency is low and needs to be running at higher rpm or higher pressure.

You can wait to see if things get better at 200 miles or remove the the VANOS and check the disc/shaft clearance and pistons motion.

[Cubieman]

Cold start was right at 100bar, it was slightly higher than 100bar for a brief time period before the vehicle went into closed loop and the idle dropped.
It then got down to 40 bar when up to temperature, wow that's low.
I talked to Raj over the phone and he is pretty confident that my low oil pressure is due to the oil pump disc shaft wearing.
I did not take a pressure reading before disassembly so I cannot say if this is the case or not.
Raj is of the opinion that my oil pressure was the same or likely worse before the new pump disc was installed due to his disc having tighter tolerances in regards to pump cylinders.
He thinks my worse vanos response times are due to the new seals having to get set. He thinks my response times will improve by 200 city miles. I am at about 125 city miles post install at this point.

Raj gave me this gauge and is going to help me out to figure out the root cause. Man, this is super disappointing to me.

Cold:


Getting up to temp: (Settled about here temp wise after 20 min)



After vehicle was up to temp. I hit the throttle of few times to see what the pressure did.

At 1500RPM (DIS test RPM) gauge read approximately 78 bar.

At 2000RPM gauge read about 82 bar

[Cubieman]

if you want you can borrow my gauge and fitting, you would need to ship it back, if you want it quick I can ship them tomorrow morning.

yes, I had to idle the car until temp was right for the test to begin. I think DIS needs the coolant to be 80C at least. Once you fit the gauge, at least on the Z4M, the hood does close, who knows on the M3. also, once the engine is hot it would be kind of tough to install the gauge and not burn your fingers.

Thanks for the offer, that is very much appreciated! Raj is shipping out a gauge for me to borrow and I will be taking to him during testing, hopefully I will have results later on this week.

[maupineda]

Hopefully that gauge will ship this week, the banjo fitting shipped already. Did you idle your car up to temp for testing?
I assume the hood won't shut on the gauge, and I guess I wouldn't really want to drive around (get vehicle up to temp.) with the gauge on there anyways for fear it might leak and I won't catch it quickly enough.

I am running Castrol TWS 10/60.

if you want you can borrow my gauge and fitting, you would need to ship it back, if you want it quick I can ship them tomorrow morning.

yes, I had to idle the car until temp was right for the test to begin. I think DIS needs the coolant to be 80C at least. Once you fit the gauge, at least on the Z4M, the hood does close, who knows on the M3. also, once the engine is hot it would be kind of tough to install the gauge and not burn your fingers.

[Cubieman]

I think once you can test system pressure you will have confirmation if the slow response is from the S62 tighter springs or pressure related. I would say stay cool and don’t stress much for now until you can measure and be in a better position to decide what’s next. If pressure is good, well get new S54 springs and swap them out. If low pressure... well, there is a pressure restriction valve you can look at, but the before test data implies it is good, so it could not broken down on its own while taken apart.

when testing your pressure you can start the engine and check pressure at cold, this will let you confirm the restrictor does its job of controlling pressure, if all is good, pressure will stay constant even at idle, at no less than 100 bar, if it starts to lower, then the pump is not capable of building pressure once the oil hots and thins out. In this case it would be the oil pump.

what oil spec are you running?

Hopefully that gauge will ship this week, the banjo fitting shipped already. Did you idle your car up to temp for testing?
I assume the hood won't shut on the gauge, and I guess I wouldn't really want to drive around (get vehicle up to temp.) with the gauge on there anyways for fear it might leak and I won't catch it quickly enough.

I am running Castrol TWS 10/60.

[Cubieman]

In light of all of this, I don't think we should run to boycott beisansystems, just be more mindful of the info presented. It's easy to get stirred emotions but he isn't SGT. Think about how many of us he's helped directly and indirectly with his DIYs.

I agree, my issue may have nothing to do with Beisans product. If that ends up being the case I will edit my first post and bold text up top saying what the other issue was. So hopefully though testing it can be identified. That being said I don't want to take my vanos off/on just for the sake of testing too many times.
These are the things I will likely be testing:
- Pressure Test
- S54 Diaphragms Test
- OE-re-drilled pump disc test
- New valve body
- New solenoid pack
- New regulator test

As noted above, the last three in that list are unlikely to be the issue as they tested out fine pre-rebuild but stranger things have happened I suppose.

l want to be very clear that Raj has been helpful with good information to me in his emails, he has told me I could call and talk, he had told me I could try a different OE-redrilled disc when available.
So I am definitely not trying to say anything negative about Beisan, this issue could have nothing to do with any Beisan product.

[maupineda]

* Bmw might not intentionally machined those 3 discs to those different length. I think it just happened in the shop setup and the dimension is not critical but they all met the spec.
* There is no oil flow at either ends of the disc, except the very small leakage via the center shaft clearance. The disc should not touch anything at either ends.
* the dimension from the cylinder holes center to the disc front face is somewhat important: too long and its end touches the VANOS block and causing stress on the roller bearing axial load, but a little short cause no harm. The dimension from the holes center to the disc rear end is total non-critical, only long enough to mate with the hub tangs.

Therefore the disc thickness is not as critical as the cylinder holes and center hole.

let me refer to the photos I posted at the beginning of the thread, please have a look and comment (https://nam3forum.com/forums/forum/m...t-beisan/page3).

The disc has two heights, and there is an oil passage at the bottom of the VANOS unit that faces to the "thicker" section of the disc. Only BMW knows what these features do to the pump performance or operation.

the images from Andrey (AK72) show different dimensions but they are of the same disc, they are different because he is measuring at different over the radii of the disc. the photos I posted show this. I don't think any OE manufacturer would spend additional machining time if it as not needed.

[Arith2]

In light of all of this, I don't think we should run to boycott beisansystems, just be more mindful of the info presented. It's easy to get stirred emotions but he isn't SGT. Think about how many of us he's helped directly and indirectly with his DIYs.

[maupineda]

Unfortunately my 3rd vanos test (75 miles city driving) is the worst yet. My second vanos test did improve a bit so I was optimistic, but after 50 miles between the 2nd and 3rd tests and a worse result I'm not sure what to extract from this.

As noted before, it was suggested that the fact that I used S62 diaphragms may be causing the delay, I can see that being and issue. These result may mean nothing but I just thought I would share this in hopes of finding out why it's been inconsistent.

24 hours before vanos rebuild:


6 Miles after rebuild:


26 miles after rebuild:


75 miles after rebuild:

I think once you can test system pressure you will have confirmation if the slow response is from the S62 tighter springs or pressure related. I would say stay cool and don’t stress much for now until you can measure and be in a better position to decide what’s next. If pressure is good, well get new S54 springs and swap them out. If low pressure... well, there is a pressure restriction valve you can look at, but the before test data implies it is good, so it could not broken down on its own while taken apart.

when testing your pressure you can start the engine and check pressure at cold, this will let you confirm the restrictor does its job of controlling pressure, if all is good, pressure will stay constant even at idle, at no less than 100 bar, if it starts to lower, then the pump is not capable of building pressure once the oil hots and thins out. In this case it would be the oil pump.

what oil spec are you running?

[sapote]

I’d have to disagree. The disc has variable thickness, why would BMW spend additional machining time if not needed? I tend to think this is necessary to allow flow around the pump so it does not see too much axial load.

* Bmw might not intentionally machined those 3 discs to those different length. I think it just happened in the shop setup and the dimension is not critical but they all met the spec.
* There is no oil flow at either ends of the disc, except the very small leakage via the center shaft clearance. The disc should not touch anything at either ends.
* the dimension from the cylinder holes center to the disc front face is somewhat important: too long and its end touches the VANOS block and causing stress on the roller bearing axial load, but a little short cause no harm. The dimension from the holes center to the disc rear end is total non-critical, only long enough to mate with the hub tangs.

Therefore the disc thickness is not as critical as the cylinder holes and center hole.

[sapote]

Unfortunately my 3rd vanos test (75 miles city driving) is the worst yet. My second vanos test did improve a bit so I was optimistic, but after 50 miles between the 2nd and 3rd tests and a worse result I'm not sure what to extract from this.

As noted before, it was suggested that the fact that I used S62 diaphragms may be causing the delay, I can see that being and issue. These result may mean nothing but I just thought I would share this in hopes of finding out why it's been inconsistent.

If you have 115 bar pressure and with the helical splines shaft, the S62 diagrams cannot slow it down more than 30% from the norm.