BMW 528i double-vanos engine sensitive to oil viscosity

[quadrun1]

"Double-VANOS" is BMW-speak for variable valve timing.

Car is a 2000 BMW 528i, it had a little bit of a hesitation from a standing start when using thicker oils (oils like 15W-40 fleet dino [used during an A-Rx rinse], and BMW's HP Syn 5W-30 during extended intervals, as it thickens up beyond a 30 wt.)

When accelerating from rest with a constant throttle opening, the car felt as if you were pressing the gas, letting off the gas a bit, and then pressing again. Kinda subtle but definitely present.

The slight hesitation just off idle is completely gone when using thinner oils like Chevron 10W-30 [used during an A-Rx wash cycle] and German Castrol 0W-30.

I thought it might be a dirty throttle body, clogged fuel filter/injectors, or intake leak.

Nope, it seems to be related to oil viscosity! Huge improvement after I dumped the 15W-40 and installed the GC 0W-30.

In fact, with GC, the engine runs spectacularly: there is a nice high-rpm "kick" present, similar to a Honda VTEC engine.

So far, this engine and GC seem to be an ideal match!

I just hope the GC doesn't thicken up to a 40 wt.

I found this regarding double-VANOS:

quote:

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At idle, the cam timing is retarded. Just off idle, the DME energizes a solenoid which allows oil pressure to move that cup gear to advance the cam 12.5 degrees at midrange, and then at about 5000 rpm, it allows it to come back to the original position. The greater advance causes better cylinder fill at mid rpms for better torque.

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I'm theorizing that an oil which is too thick will not flow quickly enough in the double-VANOS mechanism, and hence the slight hesitation.

Things may be different in the "M" engines (and the earlier BMW engines), which are spec'd to use thicker oils, but with this engine, there is a noticeable performance decrease with thicker oils.

I also find it interesting that for this series of engine, BMW explicitly approves of Mobil 1 5W-30, which as everyone knows is a thin 30 weight.

Currently, most of the other Euro manufacturers call for an ACEA A3 oil, which would mean M1 0W-40 or 15W-50.

Jason

 

[F1Crazy]

That's quite interesting theory but wouldn't you think that it would also work on a single Vanos engines as seen in M52 V8? AFAIK these engines like thicker oils and respond very well to even 50wt.

You said that engine was somewhat hesitant off idle and now it develops a surge at certain RPMs, I would take a closer look at fuel delivery on this car. On a Double Vanos the timing of the intake and exhaust cams are continuously variable throughout the rev range and there should be no power surge as seen on Hondas when V-tec kicks in.

Since both Vanos systems are hydraulicly and mechanicaly actuated they need high oil pressure. What oil will provide higher pressures, thick or thin? Maybe this is where difference comes from?

I think you may be onto something, new Valvetronic engines seem to require a bit thinner oils. SLX LL01FE, BMW's version of SLX developed specifically for Valvetronic engines is thinner than regular SLX, both are 0W-30.

 

[Dr. T]

For one, you shouldn't do wide-open throttle starts with a cold engine. That said, I too have some hesitation when accelerating with a cold engine...usually only for the first 1/2 mi..

Otherwise, I disagree with the statement "there is a noticeable performance decrease with thicker oils"....as my personal experience has shown that it is only for the first couple thou miles as the thicker oil is cleaning out the garbage left behind by the thin oil used..and hence the pressures are probably higher (gummed-up passages maybe?). In either case, I posted that I'm now getting the best fuel economy/performance ever (and I've owned the car for 170k mi.) with the 10-60.

Furthermore, I think the M3/M5 and Z8 have VANOS just as your 528 does...and they too use the 10-60.

 

[buster]

Guys, when are you going to realize that BMW are over priced junk.

Over-engineered German Liverworst....just kidding. Nice cars! My wife wants an M3! She will have to finish Medical school before she gets one of those bad boys!

 

[Asmodeus]

All BMWs have the VANOS. The new ///M all use double VANOS.

I'm interested to know that GC 0W30 works well. Friend of mine told me he went to a more viscous oil on his e39 (540) because of 'engine noise'.

I'll make sure to recommend GC.

GC for the M52TU is a necessity in the winter time.

 

[quadrun1]

quote:

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Originally posted by Dr. T:
For one, you shouldn't do wide-open throttle starts with a cold engine. That said, I too have some hesitation when accelerating with a cold engine...usually only for the first 1/2 mi..

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Who said anything about wide-open throttle with a cold engine? Big no-no in my book, too! Nice and easy with light throttle for the first 15 minutes or so.

With the 15W-40 installed, the slight hesitation was present even when the engine was warm.

I'm actually surprised by this, and just reporting my observations!

I'm definitely not a "viscophobe" (as Eiron would call it), and in fact I run M1 0W-40 in a turbo SAAB. That car loves it, and on M1 0W-40, it beats its EPA highway mileage estimate by 4 MPG! (rated 31 MPG highway, gets 35 MPG highway)

I installed M1 0W-40 in my brother's Mitsubishi and there was no performance loss in that car (Mitsu says to use 5W-30), and a nasty valve clatter was cured.

Anyhow, with the GC in the 528i, there's no hesitation whatsoever, cold or warm. No long-trip fuel mileage figures yet but based on the improved smoothness I think it'll beat its EPA rating of 26 MPG highway easily.

[ September 15, 2003, 12:27 AM: Message edited by: quadrun1 ]

 

[quadrun1]

quote:

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Originally posted by F1Crazy:
You said that engine was somewhat hesitant off idle and now it develops a surge at certain RPMs, I would take a closer look at fuel delivery on this car. On a Double Vanos the timing of the intake and exhaust cams are continuously variable throughout the rev range and there should be no power surge as seen on Hondas when V-tec kicks in.

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Well, it's not exactly the same as a VTEC kick, but there's definitely an eagerness which was lacking before. As for a fuel system problem, the car runs only Shell 93 octane and I ran a 20 oz bottle of Techron while the 15W-40 was in, no improvement. Well, no improvement seen until I drained the 15W-40 and poured in the GC!

quote:

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I think you may be onto something, new Valvetronic engines seem to require a bit thinner oils. SLX LL01FE, BMW's version of SLX developed specifically for Valvetronic engines is thinner than regular SLX, both are 0W-30.

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Yes I thought that was interesting. The new 7 series uses Valvetronic right?

There's also a VW spec for lower viscosity oils, dunno which VWs need those.

 

[Asmodeus]

The new 7er, 5er and 6er are all using Valvetronic. But I thought Valvetronic was related to the transmission.

 

[F1Crazy]

quote:

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Originally posted by Asmodeus:
The new 7er, 5er and 6er are all using Valvetronic. But I thought Valvetronic was related to the transmission.

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Valvetronic replaces throttle butterfly found in conventional engine with computer controled infinitely variable intake valve lift. This technology was first introduced in I4 engines and now is found in V12 and some V8s but it's not available on 6 cylinder engines so no Valvetronic on 525, 530. We won't see it in next generation M engines either.

 

[F1Crazy]

quote:

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Originally posted by quadrun1:
Yes I thought that was interesting. The new 7 series uses Valvetronic right?

There's also a VW spec for lower viscosity oils, dunno which VWs need those.

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Yeah, it is in both V8 and V12, new V8 X5, 5 and 6 series will have this V8 as well.
I think that the LL01 specification was created with the introduction of Valvetronic technology. LL01 spec oils have to meet ACEA A3/B3 and go through the test on Valvetronic version of M44, first Valvetronic engine.

I wonder if we'll see new oil recommendation from BMWNA with the introduction of more Valvetronic technology.

 

[Primus]

Hope you can use the following info from BMW TIS -2003:

5.0 "Longlife-01" for all engines, except:
M43/CNG, S54, S62/E39 (till 02/2000)

BMW Quality Longlife-01 0W-40
BMW Quality Longlife-01 5W-30

ACEA A3/B3

Agip Formula LL B 01 0W-30
BP Visco 7000 0W-40
BP Visco 7000 Special 0W-30
Castrol Formula SLX 0W-30
Castrol Syntec 0W-30
Castrol Super Racing 0W-40
Castrol TXT Softec LL01 5W-30
Havoline Synthetic BM 0W-30
Mobil 1 0W-40
Motul Specific LL-01 0W-30

6.0 "Longlife-01 FE" for last generation engines only: N40, N42, N62, N73

BMW Quality Longlife-01 FE 0W-30
Castrol SLX 01 FE 0W-30

(Though Russian version of BMW TIS says about ACEA A3/B3, I think this is a misprint and like Castrol SLX 01FE BMW oil is ACEA A1/B1 approved)


7.0 "Longlife-98" for all engines except:
M43/CNG, M54 (from 09/2001), N40, N42, S54, N62, N73, S62/E39 (till 02/2000)

BMW Super Power Plus 5W-30 is substituted by
BMW Quality longlife-01 5W-30
BMW Super Power Oil 5W-40

ACEA A3/B3

List of around 160 oil names and grades, some of them are:

76 Pure Synthetic Motor Oil 5W-40
Castrol Formula RS Power and Protection 0W-40
Castrol Formula RS Road and Track 5W-40
Castrol GTX7 Dynatec 5W-40
Castrol Performance 5W-40
Castrol Syntec 5W-40
Castrol TXT Softec 5W-40
Castrol Softec LL98 5W-30
Castrol Softec Plus 5W-30
Chevron Supreme Synthetic 5W-40
Mobil1 5W-30 (think it is not the same 5W-30 SS or Tri-Syn sold in N.A)
Mobil1 5W-40
Mobil1 Rally Formula 5W-30 and 5W-40
Mobil1 Turbo Diesel 0W-40
Mobil Super S 5W-40
Mobil Synt S 5W-40
Quaker State Full Synthetic European Formula 5W-40
Valvoline Durablend MXL 5W-40
Valvoline SynPower 5W-30 and 5W-40
Valvoline SynPower MXL 0W-30
Valvoline SynPro 5W-30 and 5W-40

Unfortunately I lost the page with point 8.0 "M" engines oil recommendations, but remember that for some year models it is strongly recommended to use Castrol TWS Motosport 10W-60 only. Previous oil recommendation to use Castrol Formula RS 10W-60 is void due to the change of its formulation.

Necessary to notice that many engines supplied to US market had cast iron heads instead of aluminium ones installed in Europe and some engines were made from different aluminium alloy. Seems it was made due to high sulphur level in N.American gasolene. So, I don't exclude possibility that oil recommendations may be slightly different. Think it will be useful to know that in E.Europe there were several BMW engine issues due to oil gelatinization, and namely with OW-30. According to BMW (they had to study these issues since cars were still under warranty) or, to say correctly, as customers have been said this gelatinization was caused by unappropriate quality of 95 octane gasolene: high sulphur and level of ethers and ferrocene used as octane improvers. Proposed solution: use 92 gas and don't use 0W-30. Quite strange, but I never head about similar issues in other cars with Castrol Formula SLX 0W-30. If problems concerns BMW/Castrol 01 FE 0W-30 only, then it would be also interesting to find out why.

 

[F1Crazy]

Primus, I think you're absolutely right about SLX LL01FE, it can't be ACEA A3/B3 since its HT/HS is only 3.0.

Nice list you've got there, unfortunately just a few are available here.

BTW, do you know what exactly BMW specs for Long Life oils are besides ACEA specs? I know that oils have to go through testing in specific BMW engines but not much more.