"In this new Special Series named “S85-002”, I earn a badge of honour: I blew up my V10.

I document the service history of my original S85 engine and diagnose its failure. I go through the process to source, refresh, cam and refit the replacement V10 into the E60.

In this entry, I document the current market dynamics of sourcing a quality S85 engine. I set my minimum requirements and I get my hands on my S85-002. We briefly inspect and undress common accessories."
- Matt 

2008 + is the way, right?

In the previous entry "S85s were not created equal.", I documented the various changes made by BMW to the S85 during its production life cycle.

Equipped with this knowledge, the answer to "which year should you get?" was obvious: find a MY2008 and up S85

The realities of finding a used S85 aren't that simple. To better understand what you'd be going up against, we need to understand the historical and current market dynamics of the S85.

2005 was an era of German modesty. Read the brochure!

Historical market dynamics.

The late 2000s era was tumultuous with wildly changing global markets. In 2005, BMW was setting sales records, going above 300,000 cars sold in the US for the first ever time. By 2005, BMW begun a rapid ascent to the top of the Chinese luxury car market with 30% year over year growth.

The global demand for M cars was growing, but the US was still the biggest BMW M market. 

The S85s had to be mass-produced. 

Coming off the massive funding of the Formula 1 infrastructure, BMW had invested in the first bespoke engine architecture for an M car. Expectations were set high for the S85 and it was reflected in the brand's commitment to continuously improve the V10 until 2008.  

In light of the bespoke production of the S85, BMW M most likely hoped to reach sales records to justify the massive research, development and production costs of the S85 engines. 

Like the F1 program, BMW broke records: 34,700 S85s were produced without accounting for spare blocks that BMW M most likely produced for warranty work.

The production numbers.

In most conversations, you'll often hear a 20,000 number thrown around when discussing the V10's production numbers. They are somewhat right: there were 20,548 E60s produced. This barely edged out the E39 M5 production run of 20,482. However, those numbers don't account for the M6 which ended production 2 month later.

It is the Coupé that pushed the S85 above and beyond the S62. 

In the context of sourcing a used S85, this is a great start. There's a relative abundance of supply. 

First MY popularity. 

The first Model Year (MY) is the most popular due to the being the latest and greatest product on the bloc. The E60 M5 had a lot of hype, notably from the BMW Motorsport F1 heritage and the reviewers played off of it. 

Jeremy Clarkson was at the peak of his entertainment powers when the V10 M5 came out during Series 6, Episode 9. Making the argument the M5 was "perfect" when the M button was pressed. 

"In M mode, this car is pretty hard to describe. But 'perfect' will do for the moment."

As an example, 14,589 M3 V8s were sold in the first year out of 65,985 S65s produced. It amounts to 22% over a 6 year production run. 

I couldn't find the equivalent data for the E6x M5/6, one can assume the proportions are most likely higher considering the next point.

I previously had a MY2009 E92 M3 and bought a MY2012 on my second go knowing this. 

In the context of sourcing a used MY07+ S85, this is a negative.

The Great Recession. 

In 2008, BMW M's biggest market in the world melted. BMW's stock price plunged to levels unseen since 1996, without accounting for inflation. The financial crisis of 2008 plunged automotive markets in 2008 and didn't recuperate until 2012. 

Sale and revenues dropped, but profits took a deeper dive.

Crisis are time of opportunities: BMW took advantage to reshape its operations during the future of low emissions target. The drop in sales correlated to lower CO2 emissions, it most likely served as an incentive to accelerate the transition to turbos, and look ahead to EVs. 

Used S85 market dynamics.

Fundamentally, enthusiasts have caught on: the end bell has long been run on naturally aspirated engines. The S85 sits firmly on the mount Rushmore of legendary engines for better or for worse. 

Many other factors are currently leading to dwindling used S85 supply and their increasing prices: 

1. Owners are increasingly repairing S85s over parting out cars. 
2. S85s are climbing up in years of service and failures will naturally increase. 
3. The swap market demand is strong. 

Furthermore, in S85s is expected to grow as plug and play DCT solutions are becoming available.  I may or may not have a spare unit for "testing". 

Set your priorities.

Like most marriages, there is no perfect used S85. The process of sourcing a used engine is filled with compromises. You need to set your thresholds and determine what you optimize for. 

Ultimately, you'll be operating under the usual Price / Quality / Lead Time triangle. 

1. You want relative peace of mind? Better be patient, and ready to pay a premium for an 08+ engine
2. You want the cheapest one around? Be ready to flip a coin on its condition, and the long term reliability of an 05-xx production. 

Considering BMW's documented updates to the V10, I optimized sourcing an S85 that was at minimum a 2006-01 and up production, as quickly as possible. I was ready to spend. 

Most important to me, I wanted to avoid the most expensive, mission critical update: the VANOS high pressure oil pump and its internal line. 

Sourcing my used V10.

I was lucky enough to know a great "junkyard" operator and V10 enthusiast in the Bronx. Michael had previously helped me out with a PS pump and auxiliary radiator fan. 

In the Summer of '23, he had a few S85s available including a previously running MY07 engine with a lot of mileage. The previously owner supposedly blew out the clutch and didn't want to spend more money on it. 

Junkyards have a lot of junk - more at 11. You're going to have to focus on what matters, and remember why you're doing this: to avoid your car ending up there too. 

It's all trust based. 

The only way to validate the production date of your S85 is by using the VIN from the chassis it came out from [...] and trusting the seller that the engine did indeed come from that chassis.

This chassis VIN's is WBSNB93546B584713. Per this free VIN decoder, it was produced in 2006-03-28. 

There is unfortunately no VIN engravings on the S85 block. There used to be a few stickers but they are more than likely gone 15 years on. 

This is the engine block SKU. 

Ideally, you want timestamped videos of the engine running in the chassis before having been taken out. Having some form of warranty would be great, but ultimately that is also based on trust. Lastly, a recent diagnostics for codes is useful - if there's trust. 

The engine sounded good. Michael was honest about it throwing codes for VANOS values. I could handle that. 

I bought the engine in July, with vacations and transport company delays, I ended up working out cross-border transport to InnovAuto later in September. The engine showed up on a pallet with specialize transport company. We had no loading deck, they came prepared. 

It was a beautiful day. 

View this post on Instagram

A post shared by Matt Di Vita (@m3_epoustouflant)

The S85 came with something extra: a used DCT transmission in good condition. 

My S85-002 price was inclusive of all accessories, only missing the power steering pump. Even the oil housing was dangling off the engine. 

Even the notoriously expensive AC compressor, and alternator were still bolted to the engine. 

Preliminaries. 

The first step to the S85-002 was removing all accessories from it. Our framework is to re-use previously working accessories from the S85-001 that didn't come in contact with oil flow, and potential metal shavings.

We were eager: we undressed components off the engine on the pallet itself.  

The car didn't throw codes for misfires across an entire bank. We were confident the Ionic Control Modules were in working condition. Both were removed.

Both Idle Control Actuators were present, and removed. With the car idling fine in the validation video, we were confident these were still good. 

Throttle actuators - AH! 

They had seemingly been replaced with OE replacements from VDO. 

We noticed symptoms for the probable idle misfires showing up on codes. The PCV connectors were covered in oil - indicating a potential oil recirculating issue.

AH! We found what was the probable culprit. The kinked ITB boots are often responsible for air leaks. The Idle Control Actuators end up working overtime to create vacuum, most often - it isn't enough. 

Codes are thrown, and oil doesn't adequately recirculate. 

The fuel rails and injectors were all removed. 

Another expensive part was also present: the engine starter. It had been removed before I showed up to grab pictures. 

The MSS65 had obviously been removed - but the entire engine harness was still present. 

Ignition coils and spark plugs were all there - and also fully removed. 

By using this method, you end up with a stash of spare parts, or valuable accessories that can be sold. You're looking at +/- 2,000$ in parts. 

With the S85-002 having made it safe and sound, it was time to get to work,

Up next: the V10 is put on a stand and flipped over. 

We inspect the bottom end and perform rod bearings replacement with a new variant of ACL bearings.