S65 Rod Bearings E9x M3

11 Sept

Let’s talk about the famous issue that seems to plague almost every performance BMW engine…. rod bearings!

Do I need to replace my rod bearings?

The S65 are you probably know is the naturally aspirated V8 engine found in BMW M3, produced from 2007 - 2013. This amazing engine is loved within the enthusiast community and holds a special place in the hearts of BMW fanatics. But it definitely comes with its own problems. Most famously being rod bearings.

These are known to wear out prematurely and it is recommended to have them refreshed before you hit the 70,000 miles mark as preventative maintenance. This is due to the tight bearing tolerances from factory, these bearings are referred to a 089/088. BMW also used 10W-60 for these engines, which is a thick oil. The offshoot of these two is the premature wear facing every E9x M3, S65 owner.

Some manufacturers, most famously ACL Race Bearings are doing what’s called ‘uprated bearings’. The idea being they will last longer than the OEM ones to avoid another replacement being due in another 70,000 miles or so.

It is also common to see specialist garages offering options for ARP Bolts. So what are these? These are 12 point hex bolts that are designed to be a lot stronger that standard Genuine BMW bolts. Do you need them? In our honest opinion, if you are planning to keep your engine stock, with not much track time, no tuning or mapping then BMW bolts should see you through just fine. However if you are planning to push your engine then uprated bolts are something not to skimp out on. The last thing you need is your conrod bolt failing at 7k rpm!

Should I get other work done whilst my mechanic is doing rod bearings?

Yes! The E90 M3 also is known to have failing engine mounts where they collapse and sink over time. This causes the oil sump pan to rest on the front subframe and under all that weight and vibration has been to known to crack. Obviously that causes major engine damage as the oil pressure falls to zero. Engine mounts will usually cost you around £100 and there shouldn’t be much/any additional labour incurred as all the pre-work has already been done here. We are proud to offer this additional service with no extra labour here at Element Performance.

Signs your garage will do or has done a good job

Finding a specialist that you trust with your pride and joy is difficult at the best of times but for a major job like this, you really want to make sure that they know about your specific engine and its unique needs.

At the end your garage should give you your old bearings and bolts back. Always ask beforehand and it they say they don’t do that, that’s a big red flag! With too many garages not carrying out the full work they promise this is now common practice to return the used parts, especially when on a big internal job where it is not immediately apparent if the work has been done.

Ask which oil they will use. These engines should be using 10W-60 oil, ideally Castrol. If they want to run something thinner, that’s a sign they don’t know about your engine.
All oil filters are the same right? Wrong! A lot of cheaper aftermarket oil filters lack the seal around the paper filament. This is why we always use OEM Parts or the OE Supplier for every car in our care.
Ask your garage about measuring the bearing clearances. This is commonly done using Plastigauge and is a double check essentially that everything is as it should be. Also worth asking for photos of this and a clearances data sheet for your record. If they have problems doing this, it’s probably a sign that they were not going to check them anyways!
Power steering has to be disconnected as the entire front subframe is removed for this job. Do check that new power steering fluid is used. You ideally want CHF 11S fluid.
The sump oil pan gasket should also be replaced, this is not something you want to be re-using. Also worth trying to get a genuine BMW one for your car. It is common to find aftermarket ones are ‘split gaskets’ meaning the gasket is in sections. They often are not as strong as genuine ones.

Hopefully this article has left you feeing more confident in how to approach your rod bearing replacement and how to find a specialist who will do the job properly.

Here at Element Performance, we are proud to offer everything mentioned above.

Prices start at £1500 for ACL Race Bearings and BMW Bolts. This includes all labour, parts, gaskets, oils and clearance checking. No extra costs!

Any enquires: do contact us on 07732852211 or email info@elementperformance.co.uk

You can speak directly to our technicians about any questions you may have and we can help advise you, around what suits you best.

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