E90 170k rod bearing question

[bmwpower603]

I recently bought a 2008 m3 sedan 6 speed. The car has 170k miles. It’s a dealer maintained 1 owner but has 170k. Actuators, and all fluids have been done. Everything except for the rod bearings ...

I’ve talked to various shops about getting the service done. All of them but one, said that I most likely cannot have the bearings done. Because the crank is most likely scored, and worn so doing the bearings would be pointless to replace. And a full engine rebuild is required.

Is this true? Or is there a good chance the crank looks okay, and I can just have the bearings replaced? I’m pretty sure it’s going to be a lot of $ just to pop off a few caps and observe the wear... I’m just looking to be steering in the right direction here.

Any advice would be appreciated.

[s14_kev]

How can they say this without seeing the condition of the bearings? I wouldn't assume that the crank is scored just based on mileage alone. Have you done an oil analysis to check for copper in the oil?

[Siajoon]

If your car is running fine then the chance of your crank being fine is very high.. I'm not sure why they told you that.

Just swap out your bearings and you should be good to go!

[amrazM]

Go to another shop

[bmwpower603]

I have not done oil analysis yet. I just purchased the car on Monday. I do not plan to drive it at all until the bearings are done.. So oil analysis would be judged off one oil change interval. I know bmw oil was used at BMW set interval. (8-10k) The car was never hammered on. But it was driven..

Turner motorsport are the ones who told me if the crank is scored. Then the engine needs to be replaced. 3D auto in Hudson NH told me he wants to do a full leak down test, and compression test to make sure everything is okay before replacing the rod bearings.

Im trying to make the correct decision, and the most logical decision for the car as well as for my wallet...

As for the way the cars runs.. Only issue I noticed is a hesitation/skipping at LOW rpm when you engage the throttle fully at idle. When you ease into it , it’s fine.. And it’s fine when driving the vehicle. . (I was told this is most likely plugs and coils) I have ista, no engine faults. No check engine lights.

Other than that. No knocking , no noises. Previous owner stated only bmw oil was used. And he has every single maintenance receipt.

[PKL]

How much did you pay for a 2008 with 170k miles? Shoulda bought something else IMO. Also shouldnt you have done more research about this particular car before buying it? Can you afford an engine rebuild if it comes to that?

[mapster37]

if there arent any noises im not sure why they are condemning the crankshaft. i would go to another shop....

[bmwpower603]

Originally Posted by PKL

How much did you pay for a 2008 with 170k miles? Shoulda bought something else IMO. Also shouldnt you have done more research about this particular car before buying it? Can you afford an engine rebuild if it comes to that?

I paid $12000 for the m3. I know I would need bearings, or throttle actuators. But not necessarily a crank shaft.

I’m prepared to pay for new bearings. But not an engine rebuild. .

Engine rebuild is still worth it in my option. Since it’s a rare color combo. And the last generation of naturally aspirated V8s.

Pics:

[wfdeacon88]

I think you should just do the bearings, have them check the engine while doing the service, and if it's good... you are good to go! looks pretty clean and you paid a fair price for the mileage. after that, assuming it's good to go, enjoy the car for another 100K! I'd find a shop that knows what they are doing and doesn't make crazy claims without seeing inside the engine.

PS, check that tire pressure. might be the slope, but might be low and related to the slow start. Beautiful m!

[bmwpower603]

Originally Posted by wfdeacon88

I think you should just do the bearings, have them check the engine while doing the service, and if it's good... you are good to go! looks pretty clean and you paid a fair price for the mileage. after that, assuming it's good to go, enjoy the car for another 100K! I'd find a shop that knows what they are doing and doesn't make crazy claims without seeing inside the engine.

PS, check that tire pressure. might be the slope, but might be low and related to the slow start. Beautiful m!

Well. It’s prob $1500-$2000 to just check the bearings to make sure they can do them. And make sure that the crank isn’t scored.

If they see it’s scored, and crank needs replacement I paid the $2000 and bearings weren’t done. Then I’ll need to spend 10K+ to do full rebuild lol

It might be worth having BMW do the bearings? And if it blows up, they will have to pay $25k for a new s65 ?

[Mvy]

First off, find a new shop. What they told you is not true and sounds like a place that is taking advantage. If they had said the car is due for an engine rebuild due to the 170k miles, that would make more sense. But the rod bearing scoring the crank is pure crap. Id check compression to see how tired shes running. Do the plugs and coils for sure. Next, change the bearings for piece of mind. Fact is your motor already won the lottery so its just insurance at this point. You clearly didnt have the tollerance stack issue that everyone talks about and go to that mileage. If you do some searching on here you will see people do it at many different mileages and you would have to be one of the longest running cars on here. As long as you dont have rod knock, its not likely the crank is scored. I would be surprised if a dealer would do a bearing change for you and if they would it surely would be far more expensive than an indy shop thats likely to charge $2-2.5k. No one is going to replace your motor because of a known rod bearing issue and that high of mileage unless they really screwed the pooch on the install and it happened immediately after. Im sure they would blame the mains or something else. The oil change interval from BMW being followed is my worst fear for your motors longevity, but shit its already got a ton of miles on it. Its absurd to change oil at 9-11k intervals on a motor like this. Id highly recommend you start doing it every 6k from here on out. Change the bearings to BE extra clearance, use ARP bolts and go have fun with your car. If you get 5 years out of it with that mileage you certainly got your moneys worth out of it. And who know, you could go a lot longer if your mains are in good shape. .

[pbonsalb]

Don’t let a dealer near the car unless you want a massive bill. Change the rod bearings with BE bearings and ARP studs. You will have about $1k in parts and 8 hours of labor.

There is a risk that during the change the shop will find the old bearings badly damaged and the crank scored. Nothing you can do to change that risk other than do the bearings ASAP. If you do nothing, the risk is greater that your engine will fail. Hopefully, they will be fine. If they are not fine, hopefully the crank is not damaged. If it is damaged, then you should find a good used engine, change the bearings in it, and swap it in. A used engine is about half the cost of a rebuilt engine.

You could also sell the car for $12k and spend $20k on a 100k mile car and do the bearings in it.

170k mile cars are great for DIYers to buy cheap and fix. Not so great for those who have to pay shops.

[Helmsman]

What the guys say: Don't go near that shop again! Plenty of great garages who will replace your rod shells while taking a general look around for anything else urgently needed to address.
With 170k miles - assuming shells still are fair - I'd even consider going with the later OEM shells (702/703 which are a tad more open than your current 088/089).

We all look forward to see the shells!

[VictorH]

How long and for how many miles do you plan to keep the car?

I think a properly maintained S65 is a pretty durable engine. I changed my rod bearings myself at 90,000 miles and my bearings looked fine. I now have 142,000 miles and my motor burns about 0.5L of oil between 7500 mile oil change intervals (including track days).

If you plan to keep it for a couple to 3 years and it's not a daily driver maybe it's reasonable to leave the bearings as is. If it's going to be a keeper, then by all means just take the plunge and find a shop or do the rod bearing change (if you have the skills, it's not that hard) yourself. Good luck.

[330ciprem]

The shops don't know what they are talking about - they are trying to milk you.

Just get the bearings changed - your car doesn't even have the knock! 99.9% the crank would be pristine.

[tdott]

If there is no rod knock, get the bearings changed and the crank inspected while doing it.

Find another shop, they sound like they've never done a bearing job before let alone one on a s65 and are not the type of shop you want doing this job.

Originally Posted by Helmsman

I'd even consider going with the later OEM shells (702/703 which are a tad more open than your current 088/089).

Stop spreading mis-information, OEM bearings are the worse option available today.

702/3 bearings are not more "open", the difference is negligible and within manufacturing variances. Read the Bearing Wiki and the spec BMW just published.

[Helmsman]

Originally Posted by tdott

Stop spreading mis-information, OEM bearings are the worse option available today.

702/3 bearings are not more "open", the difference is negligible and within manufacture variances. Read the Bearing Wiki and the spec BMW just published.

Different opinions, this is an open forum remember.

Assuming its the original shells, what ever shape they are in we're looking at good crank/housing dimensions. Should the shells even be in fair shape after 170K, why would he increase the clearance any further.
Ps. While I maybe would go with for instance ACL/VAC with OEM like clearance to get a softer surface for debris pick up.

[tdott]

Originally Posted by Helmsman

Different opinions, this is an open forum remember.

Assuming its the original shells, what ever shape they are in we're looking at good crank/housing dimensions. Should the shells even be in fair shape after 170K, why would he increase the clearance any further.
Ps. While I maybe would go with for instance ACL/VAC with OEM like clearance to get a softer surface for debris pick up.

Sure, you can have a hard headed opinion with no facts to back it up. Also, 702/3 not being more "open" as you put it is what I was saying was misleading/false information.

But it's pretty much a fact that any type of significant wear on the bearings even at those miles means there is a problem. OEM bearings have no chance of fixing the problem. You also don't know where in the tolerance stack the new oem bearings you put in are going to be, what if they are even tighter and push you over that edge, you'd have false hope that you can make it another 170k.

The smart choice based on years and years of industry wide knowledge is to go with a bearing that more aligns to that and has a better chance of preventing future rod bearing wear.

[tdott]

Originally Posted by Helmsman

Ps. While I maybe would go with for instance ACL/VAC with OEM like clearance to get a softer surface for debris pick up.

Also more wrong info.

ACL/VAC does not have OEM like clearance.

[pbonsalb]

While I lean strongly towards agreeing BE bearings are the way to go, BMW has more engineers than BE and chose this clearance for some reason and used it for 8 years, from the 2005 M5/6 through the 2013 M3. I would love to read BMW’s logic.

Other car makers are also reducing clearance but those are lower rpm and lower stress motors and they use oil as thin as 0W20. What BMW did goes against the industry standards but they knew those standards and had reasons for their deviations. It is now years later and BMW has not yet acknowledged any error or offered any explanation for the hundreds if not a thousand engine failures—such as blaming the owner for improper warmup or driving.

Back in 2014, before BE had any bearings to sell, I changed mine that had 60k miles to new OEM with WPC. I am curious what they look like now, 40k miles later. If I get bored and am desperate for a project, I’ll change them again. My view is that if the ones that came out looked like they still had some life left, then you don’t need to change them again until at least the same mileage — for me 60k miles. At the rate I drive, that could be 3 more years. I don’t mind changing rod bearings every 8 years.

[Helmsman]

Originally Posted by tdott

Sure, you can have a hard headed opinion with no facts to back it up. Also, 702/2 not being more "open" as you put it is what I was saying was misleading/false information.

But it's pretty much a fact that any type of significant wear on the bearings even at those miles means there is a problem. OEM bearings have no chance of fixing the problem. You also don't know where in the tolerance stack the new oem bearings you put in are going to be, what if they are even tighter and push you over that edge, you'd have false hope that you can make it another 170k.

The smart choice based on years and years of industry wide knowledge is to go with a bearing that more aligns to that and has a better chance of preventing future rod bearing wear.

Not hard headed, just an opinion. Facts to back it up in this particular case would be that it run for 170k miles with shells coming out ok, assuming this is the case.
I'm aware that 3rd party "non extended" shells like ACL are a tad more open which I'd view as perfect here to compensate for possible maximum shell thickness, with lead surface as a bonus.
The 702/703 is slightly more open, thought that was a well known fact.

Ps. May mention that I my own engine got extended shells, which I judged as a reasonable low risk solution as my 702/703 had wear at 37k miles. Time will tell whether true or not.

[SYT_Shadow]

Get the bearings changed with BE ones. There is no reason to assume your crank is scored.

There's a DIY in my signature. Parts are around 1000.



We have seen many, many engines here in the forum and the pre LCI ones are just as bad as the post LCI. Both of my E9Xs are post LCI and both of them had bearings with a lot of wear at 30k miles.