B58 Reliability

[Red pepper]

It's plenty enough for me though. Are you towing stuff?

I think it's enough for me too, I am not towing, but just to know the fact that the same car, same price, but having the "upgraded gearbox",..... maybe just jealous..

 

[DCPU]

Yes, I know, it's really upsetting that petrol version not getting same gearbox as the diesel one.....

It would be interesting question to ask one of the engineers.

From the spec sheets/wiki on ZF gearboxes it just seems the choice for the petrol was the first above the rated engine torque, so 450Nm gets you a 51 suffix gearbox; but for the diesel with 550Nm, they skipped the 70 and 75 to go to the 76. Unless the 70 and 75 gearboxes have been superceded by the 76?

Are they both 3rd generation?

 

[Ever Pragmatic]

Any thoughts on B58 reliability?

Based on a little online reading, it seems that there are a handful of known issues, but that overall, the engine is considered reliable. Thoughts from the crowd? Here are a few of links FYI:

Winner of Ward's Top Ten Engines in 2016, 2017, 2019, and 2020. For example:

https://www.bmwblog.com/2020/01/18/bmw-b58-six-cylinder-engine-wins-second-10-best-engines-award-from-wardsauto/

The 4 Most Common B58 Engine Problems:

https://bmwtuning.co/the-4-most-common-bmw-b58-engine-problems/

This seemed like a good run-down of known problems from a mechanic who - overall - likes the engine:

https://www.youtube.com/watch?v=lbc4Hs-G9Rc

I’ve run bmw 530d’s for years without a problem. The current one I’ve got has the same engine and gearbox (new in April 2022), but in single turbo version. The only problem I’ve ever had was a month ago when a mouse got in the engine bay and gnawed through the fuel pipe. £1200 to fix and apparently is due to the plastic having a by product from soy manufacturing that makes it “ greener”. It is worth noting that the replacement was a different material plus an additional shroud. BMW service at my local dealer said it was a known problem in the USA. the fact she knew about it made me “small a rat” and that this is a known issue. Engine aside, the combination of b58 and the auto box, makes for sublime motoring.

 

[DCPU]

The rodent issue with the more recent introduction of "greener" plastics has supposedly effected wiring looms also. However, it seems there's no clear answer to whether it's true.

 

[emax]

It's my experience: the most toxic glues are - technically - the best ones.

 

[painter]

I don't know when soy was added but rodents chewing wire insulation is not unheard of here in BC. A friend in Vancouver had a wiring harness in his Toyota damaged when parked at home a few years back. That caused a 'no start' and cost >$1000 CAD to replace.

And we used to camp with a couple that always set a few mouse traps under their truck hood (GMC) - and often caught rodents. He had wires chewed before.

We know critters will sometimes snuggle up to a still warm engine at night. Maybe do a little midnight nibbling. Something to think about when camping...

And then there's porcupines chewing rubber tires, hoses etc but that's another thread

 

[DCPU]

The perennial debate in my house is whether traps (well the bait) attracts them in the first place, so it's not surprising you catch them; or you wait until the damage is done and it's too late.

 

[DenisM]

Ford forums in the USA have multiple references to rodents feeding on soy-based wiring insulation....

 

[Tazzieman]

Ford forums in the USA have multiple references to rodents feeding on soy-based wiring insulation....

They have heard there is a "vegan option"

 

[burtmacklinfbi]

It is reliable enough for Toyota to use in the Supra. FWIW, I have the S58 (competition) and ZF 8 speed in my M3. It is a truly impressive platform. While the motorsport version (S58) is built up more (forged internals etc) and can handle over 1,000hp at the track, the foundation from the B58 is what helps it perform so well, and reliably. Redbull runs their drift cars with the S58 on stock internals and just check out the tuning scene for the Supra (B58) and any BMW ending with 40i. The writing is on the wall for ICE, and BMW, best known for their straight 6's, swan song is the best yet, surpassing the S54 and 2JZ while somehow putting out very little emissions. Truly impressive engineering. I should also add that the ZF 8 speed is the greatest slushbox to be ever invented and even performs 9/10th's of my PDK without having a complex dual clutch setup. There's a reason it feels like everything has a ZF 8 speed these days. It's compact, lightweight, and extremely well made for so many different applications.
The things that will give you issues is the random electric stuff (with the name Bosch written on it). Overall, I expect this drivetrain to be very reliable and under-tuned.

 

[MileHigh]

I’d like to see a chip mod to allow power to be maintained with altitude. Not a big boost in power, but every day is 6000 feet where I live and the weekends are easy 10,000, with 12-14,000 possible. Improved cooling too.

 

[emax]

Isn't an modern turbo motor controlled so that power is maintained automatically according to the current altitude? (i.e. air pressure, to be correct)

In that case, there shouldn't be too significant a difference.

 

[Tazzieman]

Isn't an modern turbo motor controlled so that power is maintained automatically according to the current altitude? (i.e. air pressure, to be correct)

In that case, there shouldn't be too significant a difference.

1960s 6.3L Benzes had altitude compensators, , not surprising since from memory the Bosch fuel injection systems were derived from WW2 Messerschmitts.
A 2022 vehicle should be able to cope!

 

[Disco Dave]

Isn't an modern turbo motor controlled so that power is maintained automatically according to the current altitude? (i.e. air pressure, to be correct)

In that case, there shouldn't be too significant a difference.

A turbo will increase atmospheric pressure by a certain amount. Will it increase the pressure to the same value at 10,000ft, as it will at sea level is the question.

 

[MileHigh]

My understanding was that turbo cars run relative to a vacuum, so your get X lbs of boost- no matter the altitude. The WWII fighters had multi-stage turbo/superchargers running at different configs as different altitudes. Makes a mockery of ‘this plane was faster than that plane”- which model, which octane gas, with water injection or with out…

https://www.youtube.com/c/GregsAirplanesandAutomobiles

If you are an engine person or think you know the ins and outs of WWII airplanes- don’t go unless you want to loose an afternoon.

 

[emax]

I have never heard of that. It would completely contradict what turbo engines are for in airplanes: to counteract low air pressure. But that's the way it is with airplanes.

I do however not understand why a motor should work differently and thus loose one of the biggest advantages of a turbo engine.

 

[MileHigh]

From what I understand the turbos on automobiles are rated for a certain amount of boost. That boost is over ambient conditions. So a turbo car will do better than a normal aspirated car as altitude increases but unless you modify it specifically to increase the boost as ambient air pressure decreases, I don’t think it’s a automatic thing. I think in airplanes the turbo system is different and the waist gate is set to provide a certain equivalent altitude pressure to the engine up to a critical altitude. It also sounds like the turbo efficiency changes as altitude increases because of the less dense air.

my point was that you should probably chip the BMW engine to add more boost and keep it near the official horsepower ratings. But then you have a thermal management issue.

when jeep launch their grand Cherokee with the turbo diesel I asked them this very same question, and got nothing in return.

 

[DaveB]

I thought I would ask Mr Garrett as it is Garrett turbo's in both the petrol (Single turbo)and Diesel (Twin Compound)
Also a good video explaining how different turbo setups work

Turbocharging At Elevation

A naturally aspirated combustion engine will lose 3% of its power for every 1,000 ft of elevation gain. Add a Garrett turbocharger to minimize the loss

www.garrettmotion.com

 

[DaveB]

A couple of things that this article mentions that I haven't seen anywhere else. This refers to the B57 Diesel but I believe they may be the same on the B58 Petrol

The Tech Behind the Garrett Turbochargers That Keep BMW B57 Diesel Engines Alive

Let's explore the innovative technologies behind Garett's two-stage VNT turbos used to improve efficiency and reduce emissions on BMW's B57 diesel engines

www.autoevolution.com

 

[MileHigh]

To me, it's all about the wastegate settings. Is it set for 13lbs over ambient? For a set point over absolute vacuum. For the engine to maintain power, it s going to need to know what its altitude- or at least density altitude is. Otherwise it will just put out a set amount over some set point.

Of course turbos CAN give you better performance at higher altitides, but they have to be set up for that. My guess is that with probably 95%+ of people living at altitudes that don't need to adjust boost, that they don't use that feature. Be cool if they did.