This weekend I worked on a tool to remove the crankshaft pulley bolt from the crankshaft. I rebuilt an N54 a few months ago and that bolt was unbelievably tight. My DeWalt 20V 1/2" electric impact gun couldn't get it out, and it's supposedly good to 1,000 ft-lb. Last time around, I bent the crankshaft trying to extract the bolt because I didn't have the right tool for the job.

This time around, I wanted to fabricate the right tool. I hunted around work for a piece of scrap steel approximately the right dimensions. I settled on a steel plate roughly 3" x 6" x 1/2". Then I machined the appropriate bolt pattern for the holding screws, as well as a precision bore for the center hub. Finally I had my friend weld the plate onto a piece of steel tube I bought at a local metal shop's scrap bin for a couple bucks.

Happily the tool worked! I have no way of knowing for sure, but I estimate it took about 400 ft-lb to remove the bolt. I had to use a cheater pipe on the breaker bar in order to get enough torque. You could visibly see the pin-hole on the breaker bar elongating under the load.

Today I stopped in at the crankshaft machine shop to have the original crank inspected and to get repair quotes. Repairing my original crank would cost about $325, and include welding + grinding the damaged lobe. The others would be ground & polished as needed to remove any scoring. For this engine, oversize replacement bearings are only available for mains, not for connecting rods. So they would only be able to be polished.

They could also polish the ebay used crank, but didn't recommend that option as highly. That would cost about $165.

As long as I'm changing out the main bearings, it seems like the best option is to buy the remanufactured OEM crank + bearing set for $1400. I'm pretty confident I have the best price on that. If I'm re-using the old bearings, then the better play is to repair the crankshaft and reassemble. As can be seen from the spreadsheet, bearings are actually the most expensive part of the project.

Any updates?

Any new tools made? :)

Nothing too exciting to report; I'm on vacation at the moment. I placed the order for repair parts and it totaled about $2050. I still have not yet sourced a replacement connecting rod, which is a major issue. BMW only sells a set of 6 for $611, ouch.

If anyone has a possible source for an N55 connecting rod, please let me know...

You could try Bavarian Auto Recycling, some people love them, some don't. YMMV. BMW Parts used and rebuilt bmw auto parts

Down the road from me.... Personally Ive found that their used prices are within 20% of discounted online dealer prices....

Big Mikes in Michigan is showing an N55 listed as "parts" for $500. They may be willing to part out the rods. 1-586-468-8244

Yep. I've heard the same.

I called Big Mike's and they simply said "we don't have any N55s." Can you tell me where you found it on their site?

Bavarian Auto Recycling also said they didn't have any cores. I've cold-emailed a bunch of eBay sellers who sold other N55 components but so far all have said they don't have rods.

Update! Using the car-part interchange I found a place with an "engine core" for sale. I called and they agreed to sell me a rod for $150 plus shipping. Expensive, but it sure beats $600 and having to eBay the remainders.