Any engine experts that can help re some technical questions on an bmw s85 motor?

Craze,
I had a similar situation when a friend was showing his engine builder his drain plug. It had a fragment on it and the builder was stumped. I happen to be visiting and asked him if he ran a hub. He said yes. I told him it was part of his timing gear tooth and he should pull it apart and replace the timing set and put a harmonic balancer on it. The builder had a brief discussion about not needing one. I explained the evidence for my suggestion was held in his hand. They changed it and avoided a catastrophic failure.
As a back ground, I had several years of race engine building in a small two man shop. We had a client with a stock based small block chevy come in and explain that he has figured out how to make his engine accelerate harder off the corners. (Sorry, but I started as a roundy round kinda guy.) He said if you cut the big ring off the outside of the thing on the crank that you bolt the pulley on, it hauls off the corner. My boss explained to him that he should bring his engine in and let us repair the damage now before it came apart. He declined saying he was performing regular maintenance and was on top of it. It exploded the next Saturday when it snapped a timing chain. Killed two pistons and rods and trashed his cylinder head.
Harmonics can kill things quickly.
Just another old man telling stories of days gone by. Hope you enjoyed it. I am going for more coffee.

Glad to know you are on the right track to sort out your engine. Happy motoring.

 

Craze,
It is clear that you have a grasp on this. I will say I have learned years ago that "People don't know when they don't know." That makes a lot of people do things they think they know. But they just don't know. I am not super smart, or highly educated, but I have a natural gift of understanding mechanical things and usually can tell when I just don't know. Then research teaches me. I am really enjoying following this thread and will be very interested to learn what you find out next.
I have my popcorn ready.

 

Good to know. Thank you for sharing and challenging our minds.

 

That's crazy about the slide valve stuff.

As far as the new noises.. do these people test drive the cars after they put them back together or ?

You must really love this particular BMW

Ray

 

There are certain car brands I refuse to own, simply because their engineering makes no sense whatsoever... and BMW is one of them.

Get a Toyota or a Lexus my friend. Life is too short to deal with the kind of stuff you are dealing with over there.

Ray

 

Probably the car sits for longer periods of time. Have been a BMW tech for 12 years and seen this stuff happen with cars that are not being used alot + materials theese days are just not what they used to be.

@RayJohns it's not the brand, its the engine. S85 is one of the most complex machines put together and when maintained poorly or being worked on by the people that havent seen them alot it can cause issues. A Toyota or a Lexus will never give you the proper goose bumps that an S85 gives you when you rev it to almost 9krpm

But yeah, comes with a hefty price tag.

We have a practice in Europe of preventative maintainance for theese engines for some of the issues on theese cars and they run just fine. But yeah, its a costly engine to own. But the soouuund... The F1 sound is just amazing.

I also own an E39 M5 which is a far superior vehicle (in my opinion) to the S85 with an engine that is not problematic (if you maintain it right) and i have done 342.000km with it. First lower end. Despite the age, my car pulls to 300km/h without any issues. But, the sound is another world compared to the S85 (depends on the taste of course).

P.S The E60 is one of the series neither i want to own. It was a revolution in technology, but costly to maintain in the long run. But this car has put together a road for todays cars coming from BMW. The F10/F90 M5's are just monsters to drive around with the twin turbo V8's. If you can survive the weight

The new series turbo engines from BMW (S55, ..) are just monsters. I have seen alot of them passing even 300.000km without any serious issues.

 

It's always the engine sound that gets people - me included

Thanks for the info on the BMW motors. I'll check YouTube and see if I can find some videos, etc.

Ray

 

The BMW E39 M5 you mentioned seems to be positively regarded there on YouTube all right.

My ex-girlfriend's father had a BMW M5 (E28), so I'm somewhat traumatized by the whole M5 idea.

If someone twisted my arm and said you must to own a BMW, the only one that comes to mind would be maybe an older 1970's era BWM 3.0 CSi. I'm not a BMW guy, so I don't know much about them (outside of their looks and that most cars from the 1970's are nicely produced in general). I feel like there is also some possibility of running sidedraft carbs here (on the 3.0 motor) maybe haha.

Ray

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@RayJohns the E39 M5 is one of the best sedans ever made. It really is. Its a daily useable car with far less issues then the E60. I have mine sitting on B16 Billsteins with an additional oil cooler and some other mods. I also track my car sometimes and drive her daily (not so much anymore, i have a diesel now for a daily since gas prices in €urope went ballistic the last few years) but yeah one of the best investments i made. I bought this thing (i wanted it since i was a younger version of myself) for app 7k$ and right now the value is sitting around 20-25k$ for a nice one, mint ones going for twice that value.

The M3 is a bit small for me (kind of a big dude with 195cm) so the 5 series is wonderful in that regard. You should definetly try one.

The engine puts out 500Nm of torque (369lb-ft @3900rpm) but the torque curve is amazing since you can use the low end torque for daily driving.

Imagine an American made V8 torque figures combined in a German car with performance and chassis ability to make a fast corner )

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Look at the tq/hp curve over for E60 M5/E39 M5.

So for me as a daily usable road car the E39 definetly wins by far. The E60 is kind of laggish and slugy in the down low rpm area but a complete monster at 4krpm+. Its an F1 car when you hit the limiter.

I guess it all depends what you want from a car. The E60 M5 is definetly not an “economic decision or a rational one” in that sense. You get an F1 car that sings to you when you hit the limiter with an amazing features (for its time) and on the other side its one of the most complex machines built, with alot of issues that come with time.

Its also an absolute gas-guzzler when you want it to move, but it moves like a supercar i had a track session in RedBull Ring (F1 Austria) where i had emptied the whole tank on an E60 M5 in 18 laps (aproximately 80km) and sounds amazing. The E39 is more of a muscle car sound that moves through the whole rev area but there is no cherry on top that the E60 has when it moves past 4k. It actually feels a bit boring when you get close to the limiter (but the exhaust headers get rid of that because the factory ones are restrictive)

So yeah, can understand both sides of the story. For me to own a second ///M car it would definetly be an E92 M3. Its a proper track tool with all the pros of an E60 M5 (the S65 engine in it is actually a copy/paste V10 S85 but missing 2 cylinders )

@craze we actually rebuild alternators in Europe, my suggestion is keep your spare one and have it rebuilt so you have a spare one with no larger expense regarding the plastic parts they deterior with age so its a must to have them changed. Ive done numerous rod bearing jobs on the E60/E92/E39 ///M cars and they all suffer from this.

Cant say about the top speed, never tried it in an E60. Drove my E39 300kmh+ and a 599 aproximately 335km/h and never tried it again…

 

It is easy to be defeated but you may also be close to resolving the issues as well.

The mechanical gear noises is a bit generic, was the BMW tech able to give some insight? It could be an assembly issue or something simple maybe a partial tear down and reassembly to ensure that nothing stupid has been done or …. A gear noise could have a simple cause especially if it hasn’t been catastrophic yet. Good luck!

 

That sucks man. Sorry to hear you are still going through all this.

Do the people building your motor actually know anything about this specific BMW motor? Seems like they are fumbling around in the dark over there.

Ray