Rod Bearing Replacement

yellaboyla

Lurker
Dec 29, 2019
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2008 535i
I believe my I just spun my rod bearings. 2008 535i 125k. It happened while it was parked, and maybe 5 min of engine on time. I have access to a lift. I need to throw on my FBO stuff, so I don't mind dropping the subframe. Have engine brace already. From reading this thread, seems pretty straight forward. What should I order? Imma prob do it over next weekend.
 

The Convert

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Jun 4, 2017
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I believe my I just spun my rod bearings. 2008 535i 125k. It happened while it was parked, and maybe 5 min of engine on time. I have access to a lift. I need to throw on my FBO stuff, so I don't mind dropping the subframe. Have engine brace already. From reading this thread, seems pretty straight forward. What should I order? Imma prob do it over next weekend.
What makes you think you just, “spun your rod bearings”?
 

Bnks334

Lieutenant
Dec 1, 2016
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New York
I believe my I just spun my rod bearings. 2008 535i 125k. It happened while it was parked, and maybe 5 min of engine on time. I have access to a lift. I need to throw on my FBO stuff, so I don't mind dropping the subframe. Have engine brace already. From reading this thread, seems pretty straight forward. What should I order? Imma prob do it over next weekend.

I think this is the main stuff:

* Oil pan gasket and bolt kit 11137548031 & 11132210959
* Rod bolts - 11247589671 (12x - 1 time use)
* Oil pump + windage tray bolt kit - 11410426472 (1 time use )
* O-ring for oil pickup tube - 11417527092
* Turbo oil drain o-rings - 11427563453 (2x)
* Power Steering pump bolts (I usually re-use these on the N55's I've worked on, but, N54s seem to have bolts back out on them so I would upgrade to the latest N55 part number 07129905738; they are made of different material)
* Green plasti-guage for .001-.003"
* Brake clean
* lint-free rags to clean with
* STD size rod bearings (assuming the crank and rods are still good)

Hope the main bearings are OK...

Newtis.info has everything you need instruction wise and torque specs. This is a time consuming job. Lot's of things to unbolt to get the pan off. Ends up being like $300 in materials to hopefully save an engine. Expect to have to swap the engine if the carnage is that bad. Cranks form stress cracks, journals get damaged, Cranks get warped, rods get stretched...
 

yellaboyla

Lurker
Dec 29, 2019
14
3
0
Ride
2008 535i
Thanks!!

Bearing should be ok..Short story;
Bought car, said engine was seized. Was the compressor. Wasn't started for over 7 months. I changed compressor, starter and battery. Engine was bone dry. While starting, the coupling from the oil cooler popped loose. Lost 2 quarts of oil. Before it came off, i checked oil. was clean. after fighting to start it, oil showed the glitter, and tapping under valve cover. I haven't ran it 10 minutes, so anything that happened should be very minimal.
 

yellaboyla

Lurker
Dec 29, 2019
14
3
0
Ride
2008 535i
I think this is the main stuff:

* Oil pan gasket and bolt kit 11137548031 & 11132210959
* Rod bolts - 11247589671 (12x - 1 time use)
* Oil pump + windage tray bolt kit - 11410426472 (1 time use )
* O-ring for oil pickup tube - 11417527092
* Turbo oil drain o-rings - 11427563453 (2x)
* Power Steering pump bolts (I usually re-use these on the N55's I've worked on, but, N54s seem to have bolts back out on them so I would upgrade to the latest N55 part number 07129905738; they are made of different material)
* Green plasti-guage for .001-.003"
* Brake clean
* lint-free rags to clean with
* STD size rod bearings (assuming the crank and rods are still good)

Hope the main bearings are OK...

Newtis.info has everything you need instruction wise and torque specs. This is a time consuming job. Lot's of things to unbolt to get the pan off. Ends up being like $300 in materials to hopefully save an engine. Expect to have to swap the engine if the carnage is that bad. Cranks form stress cracks, journals get damaged, Cranks get warped, rods get stretched...
oops...see above
 

Bnks334

Lieutenant
Dec 1, 2016
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New York
How do I know what thickness to use? I see diff ones...

Did you read the newtis.info guide? It explains how to get the code for which BMW bearings to use. Crank shaft is stamped with Y or R indicating standard red/blue or other shells. BMW mixed and matched shells to get every journal as close to target as possible. Target being somewhere around .0015" I believe.

No one really bothers using bmw bearings though. They are like $25 per shell. Expensive. You can get a standard set of builder bearings of the same quality for like $100. You're clearances just might have a bit more variance. Every e gine I've done usually lands between .0015" and .002" which is fine.

If you're just preventivly swapping bearings you should be able to just order up some King or ACL stadard (std) bearings and torque them in place with some plastiguage. Use your old rod bolts to do this. Check the clearance. Comes back between .0015" and .002" the. You're good. Clean off the plastiguage and re-torque using new rod bolts. If you have a journal that is way too loose or way too tight then you might have a bigger issue to look into. Most likely the bmold bearings would be showing some abnormal wear too.
 
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yellaboyla

Lurker
Dec 29, 2019
14
3
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2008 535i
Did you read the newtis.info guide? It explains how to get the code for which BMW bearings to use. Crank shaft is stamped with Y or R indicating standard red/blue or other shells. BMW mixed and matched shells to get every journal as close to target as possible. Target being somewhere around .0015" I believe.

No one really bothers using bmw bearings though. They are like $25 per shell. Expensive. You can get a standard set of builder bearings of the same quality for like $100. You're clearances just might have a bit more variance. Every e gine I've done usually lands between .0015" and .002" which is fine.

If you're just preventivly swapping bearings you should be able to just order up some King or ACL stadard (std) bearings and torque them in place with some plastiguage. Use your old rod bolts to do this. Check the clearance. Comes back between .0015" and .002" the. You're good. Clean off the plastiguage and re-torque using new rod bolts. If you have a journal that is way too loose or way too tight then you might have a bigger issue to look into. Most likely the bmold bearings would be showing some abnormal wear too.

ok..I will read over it. Thanks for the info.

I definitely have 1 that spun or has gotten loose. Getting the rattle of death, but idle is super smooth. The engine literally ran under 10 min with the knock. it was not started for 7 months, i checked oil, clean, dumped it, put in more oil, started the engine, no knock for 1min, then it started. I cranked it a few times, checked the oil, saw glitter. Haven't started or drove it.
 

ShocknAwe

Captain
Jan 24, 2018
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N54/3 1er ///Mutt
My N54 is at a machine shop due to rod knock. Machine shop said I would need 0.5mm oversized rod bearings. MMP said they dont have any, what are some other options?

Needs fact checking from a more experienced member but I believe you are describing these.

 
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Bnks334

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Dec 1, 2016
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My N54 is at a machine shop due to rod knock. Machine shop said I would need 0.5mm oversized rod bearings. MMP said they dont have any, what are some other options?

Lots of options on ebay and elsewhere...


Machine shop is calling for a undersize bearing because they are probably cutting the crank shaft to repair damage to the journals. The .5 bearings are thicker to account for the new smaller crankshaft journal diameter.
 
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gmagnus7

Corporal
Dec 3, 2018
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135i N54
I agree about checking the clearance first and don't just blindly install them. Honestly, I'd like to see none less than 0.002". That's already considered tight for a 30 wt oil, never mind 40 wt's. 0.002" to 0.0025" is also the sweet spot for bearing load capacity. Larger clearances also mean cooler operating temps, more oil can flow through and cool the internals for a given pressure. If I ever do mine (maybe the next time the pan is down?) I'll get them properly done, even if it's by a shop.

Edit: The cooler internals may compound the stock oil cooler problem on these cars, not sure.
 

Bnks334

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Dec 1, 2016
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New York
I agree about checking the clearance first and don't just blindly install them. Honestly, I'd like to see none less than 0.002". That's already considered tight for a 30 wt oil, never mind 40 wt's. 0.002" to 0.0025" is also the sweet spot for bearing load capacity. Larger clearances also mean cooler operating temps, more oil can flow through and cool the internals for a given pressure. If I ever do mine (maybe the next time the pan is down?) I'll get them properly done, even if it's by a shop.

Edit: The cooler internals may compound the stock oil cooler problem on these cars, not sure.

With a virgin crank and rods, you can mix and match std shells on the cap side and "x" shells on the rod side to gain .0005" clearance. That should produce .0022" or so of clearance from my experience. There is a limit to how much you can open up clearances since small changes to clearances can exponentially increase the volume of oil needed to maintain the same oil pressure. N5x oil pumps seem to have decent overhead but there is a limit.

Since the crank is being cut, he would need to contact the machinist to find out what kind of clearance will be produced since he is doing a stage 2 repair on the crank and calling for .5mm undersize rod bearings.
 

Torgus

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Nov 6, 2016
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ok, well got the pan off. only the top part of bearing on #6 came loose. the bottom was in place with tab and lip on walls. the crank and rods all look the same...no scratches or damage.

Congrats!
 

doublespaces

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Oct 18, 2016
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ok, well got the pan off. only the top part of bearing on #6 came loose. the bottom was in place with tab and lip on walls. the crank and rods all look the same...no scratches or damage.

Thanks for reporting back, good to see a positive outcome every once in a while.
 
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Coupes66

Corporal
Dec 26, 2017
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BMW 335i N54
ok, well got the pan off. only the top part of bearing on #6 came loose. the bottom was in place with tab and lip on walls. the crank and rods all look the same...no scratches or damage.
If all of the bearings look ok, then what is causing the knocking noise? Can you see if any of the conrods are slightly bent. This was the cause of knocking noise in my engine.
 

yellaboyla

Lurker
Dec 29, 2019
14
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2008 535i
If all of the bearings look ok, then what is causing the knocking noise? Can you see if any of the conrods are slightly bent. This was the cause of knocking noise in my engine.
Maybe I didn't post it right. Only cylinder 5 was loose. When I pulled the bottom of the rod, that bearing was in place, but worn. The top of 6 was disintegrated. The crank and piston rod looked fine. No damage. The other rods were tight, but I went ahead and pulled those, too. Very minimal wear. Ordering parts now.
 
Last edited:

yellaboyla

Lurker
Dec 29, 2019
14
3
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Ride
2008 535i
Buy an oil pump bolt kit, you'll need it for the windage tray and oil pump bolts.
I have Bearings in stock if you need them as well :) Lots of them.
If you want them coated as well, not an issue.
No, you don't have to pull the bedplate for rod bolts like someone mentioned above.
Hey, i need some bearings. Coated or whatever you recommend. I am right down the road in Lake Charles. I ordered the bolts from FCPeuro......