How bad is the Rod Bearing Issue?

Hey everyone. I'm pretty new to E9X M3s but I've heard that rod bearings are a pretty standard maintenance problem for most of them. Is this true? I'm looking to get one of these cars myself! Also, if I was to replace my bearings, how long would the new ones last hypothetically? Is there a general range that new bearings can last on these M3s? Thanks!

Check out Rod Bearings Condition thread and decide for yourself

Welcome David. This one you simply have to spend a few minutes of your own time to search and obtain a first level feel about. There is a TON of information on the subject.

How many miles will your car have? I would replace them with either BE or ACL extra clearance bearings just to be safe. Swap engine mounts as well while you’re in there.

With new bearings u have an engine with a lower chance of grenading. And its an expensive engine so that's why they are often changed out.

Helmsman wrote

Welcome David. This one you simply have to spend a few minutes of your own time to search and obtain a first level feel about. There is a TON of information on the subject.

I did some research on the topic like you asked. It was very helpful but also very overwhelming! After reading some forums I heard that VAC bearings are the way to go with a bit of a larger clearance, but that also main bearings are becoming an issue? What are aftermarket options for main bearings?

David_Vasha wrote

I did some research on the topic like you asked. It was very helpful but also very overwhelming! After reading some forums I heard that VAC bearings are the way to go with a bit of a larger clearance, but that also main bearings are becoming an issue? What are aftermarket options for main bearings?

Welcome to the club. Did a good couple of year research before I eventually replaced mine (ACL HX). VAC, ACL and BE you will find are three popular aftermarket brands all with extended clearance options.

Here's a good page for general deep dive although obviously with BE as preferred solution: https://bebearings.com/

Personal though; better to replace the rod shells with what ever (incl OEM) than hope for the best. It's a one time $2.5k exercise e.g. what you end up spending anually on insurance and oil.

Ps. Oh, and the main bearings are such a small percentage issues this far so would personally not bother about them at this point.

I'll just add that I was in the camp of "S65 rod bearing hysteria is an internet hoax".

But after watching people post pictures of their OEM rod bearings for 2 years, and not seeing any that I thought looked normal, I decided to change mine with the BE stuff.

And even then, when I started the DIY, I was certain I was going to pull the first rod cap and be mad at myself for opening the crankcase for no reason.

This car, while supercharged, has always lived in a mild climate, always garaged, always warmed up, meticulously maintained and had stellar oil analysis results for the 8000 miles prior to the RB change out.

I wasn't prepared to discover that my rod bearings looked like this at 65,000 miles…

Mains are a lot more involved

S65 Engine Main Bearing Service, Documented https://www.m3post.com/forums/showthread.php?t=1504062

This is crazy, how did BMW get away with this major engineering flaw? I understand that these engines are very fun to drive but damn I'd still be scared to rev it up even after a rod bearing change. Are there any situations of aftermarket rod bearings failing prematurely (I know there's the possibility of installation error)? I was originally hoping this DIY would be a one and done but I get the feeling that this is a recurring maintenance issue to perform every 50k miles or so. I could be off though. If so someone please correct me here. I would love to be wrong.

David_Vasha wrote

This is crazy, how did BMW get away with this major engineering flaw? I understand that these engines are very fun to drive but damn I'd still be scared to rev it up even after a rod bearing change. Are there any situations of aftermarket rod bearings failing prematurely (I know there's the possibility of installation error)? I was originally hoping this DIY would be a one and done but I get the feeling that this is a recurring maintenance issue to perform every 50k miles or so. I could be off though. If so someone please correct me here. I would love to be wrong.

There have only been a few cases where a second set of replacement bearings have been installed. Some cases where replacement bearings were examined after some other failures generally have shown improved wear patterns. It is likely more of 100k miles maintenance item. People tend to replace the originals earlier as it is much cheaper than a replacement motor.

David_Vasha wrote

Hey everyone. I'm pretty new to E9X M3s but I've heard that rod bearings are a pretty standard maintenance problem for most of them. Is this true? I'm looking to get one of these cars myself! Also, if I was to replace my bearings, how long would the new ones last hypothetically? Is there a general range that new bearings can last on these M3s? Thanks!

To be honest , the list is 'very long => https://www.m3post.com/forums/showthread.php?t=786615

On the other hand : We can see S65's running with 200K+ on it , and with original bearings .

Personally , I see the S65/85 as a German Lottery !

David_Vasha wrote

Hey everyone. I'm pretty new to E9X M3s but I've heard that rod bearings are a pretty standard maintenance problem for most of them. Is this true? I'm looking to get one of these cars myself! Also, if I was to replace my bearings, how long would the new ones last hypothetically? Is there a general range that new bearings can last on these M3s? Thanks!

I change the rod bearings with every oil change, they don't last long at all

MPG_LOL wrote

David_Vasha wrote

Hey everyone. I'm pretty new to E9X M3s but I've heard that rod bearings are a pretty standard maintenance problem for most of them. Is this true? I'm looking to get one of these cars myself! Also, if I was to replace my bearings, how long would the new ones last hypothetically? Is there a general range that new bearings can last on these M3s? Thanks!

I change the rod bearings with every oil change, they don't last long at all

I figured as much. $2,500 every oil change sounds like a damn sweet deal to me.

Rod bearings are like covid. Many people believe it exists and get their shots. Some don't, and some of that group contract it and die but others don't. So it's up to you to decide what to believe and to roll the dice.

I did mine at 130k, I'm 2nd owner, was on original Bearings, good thing I change it!

If you still haven't purchased a E9x M3, you must take into account that most maintenance items cost more than a more common vehicle. If you're not doing the work yourself, you can expect to pay around $100 per hour shop time for a mechanic. Parts such as throttle actuators have come down in price, but others are still expensive. Price out parts for brakes, tires and other more rare replacements and you will get a better feel for the cost of ownership.

Redd wrote

Rod bearings are like covid. Many people believe it exists and get their shots. Some don't, and some of that group contract it and die but others don't. So it's up to you to decide what to believe and to roll the dice.

Cool

There are clear costs involved for admission to the ///M Club. Always have been. These are not Honda Civics that only need regular oil changes to get 300k miles out of, but instead cars that have been designed to push limits in all directions. Each platform has had its own issues. E36 had the shit cooling system, E46 was Vanos and subframe, and here the E9x has it's rod bearings.

Personally if I don't have paper showing they have been done by a PO, I will be doing them myself when I buy an E9x. It is simply insurance against the possibility. There are lots of examples of the bearings lasting for many years, even the first versions before they made the change to the non-copper bearings. But for every one of those there is someone like Davisca455 who found out how close they came. So, just like the first thing you do when you buy an E36 is you get a cooling system refresh or the E46 you check and reinforce the subframe and do the Vanos solenoids, with the E9x you do the rod bearings. Plain and simple.

70,000 miles, daily driver, several track days a year and no issues (yet?). Not worried.

drrust wrote

If you still haven't purchased a E9x M3, you must take into account that most maintenance items cost more than a more common vehicle. If you're not doing the work yourself, you can expect to pay around $100 per hour shop time for a mechanic. Parts such as throttle actuators have come down in price, but others are still expensive. Price out parts for brakes, tires and other more rare replacements and you will get a better feel for the cost of ownership.

Other than the rod bearings and tires, I do the rest of the work myself, I am by no means a professional, but I do try to save money in that department by doing it myself.

David_Vasha wrote

drrust wrote

If you still haven't purchased a E9x M3, you must take into account that most maintenance items cost more than a more common vehicle. If you're not doing the work yourself, you can expect to pay around $100 per hour shop time for a mechanic. Parts such as throttle actuators have come down in price, but others are still expensive. Price out parts for brakes, tires and other more rare replacements and you will get a better feel for the cost of ownership.

Other than the rod bearings and tires, I do the rest of the work myself, I am by no means a professional, but I do try to save money in that department by doing it myself.

Seriously, if you're considering buying one and you're fretting about the cost of a rod bearing job, price out other parts that are likely needed. It helps to know what to expect. Some parts can be purchased through FCP Euro and be warranted (even oil and filters). But many parts are only typically needed once (depending on how you drive).