N54 Rod Knock what to do

Matt's 08 335i

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May 18, 2018
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Hi everyone,
So any advice would be much appreciated for my situation, that I'm not to sure what to do. I have a 08 335i that sadly has given me my final good by. Recently the car was making a ticking noise under throttle above 2k. I do what I can to my car myself, so any noise that I hear that is not normal I notice instantly. After reading countless forms and listing to other videos it sounded like rod knock. Long story short I took my car in to my normal Indy shop and they confirmed what I though. So here's my situation. I own 9k on my car still. It's going to cost me so much to break down the engine and have it machined. I have no idea if I will need a new cam or any other parts that might need to be changed as well, or even a new oil pump who knows. It would probably be cheaper to just buy a used engine at this point. I figure for a engine is about 2k and some change, install would probably be a couple of grand as well. With all that work it would not be worth it for me to keep the car, nor do I have the funds for it. I dont know what to do with it. Do I just sell it for what its worth and take what I can get? The car has 70k miles on it and is an AT. What do you guys think I should do. If the car was a manual maybe I would keep it and rebuild. All I know is that this sucks, but this car has been a nightmare for me, new power steering pump, new water pump, new index 12 injectors, sensors after sensors replaced, value cover, oil pan, coolant and oil gaskets. Any advice would be nice thanks in advance.
 

Rob09msport

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Sounds like you have done alot already why throw that all away you can prob find a block for closer to 1k than 2 if you look around and transfer all your new stuff and im sure if you look around should be able to get the install done for more like 1200 to 1500 .on other platforms i have heard of people changing the bad bearing and getting alot of life out of engine also e60 m5 amd e92 m3 guys upgrade their bearings all the time i would maybe look into having a performance shop that works on s65s give price as seems like thats standard maint on those engines
 

doublespaces

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Good luck selling a car that still has a lien on it. Just get the rod bearings replaced if you can. If not put in a used motor, I see them sell for $1500 and you can do the install yourself. This is just a bad situation and you gotta deal with it. These are actually pretty expensive cars, they have just depreciated a lot.
 
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fmorelli

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May I ask where you are located and who the Indy shop is? 70k miles, nothing in the motor should be worn out. Not sure what exactly failed or why (how is the car configured ... any explanation behind the failure?) Did the Indy's look at the oil? Oil analysis?

Filippo
 
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langsbr

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I don't think you can just replace the bearing if it spun. The M3 and M5 guys that replace bearings do it before they spin one due to excessive wear. You'd at a minimum need to get the crank journal polished, and you still run the risk of having metal in the engine unless it's fully cleaned properly.

Unless it's a total DIY job to save money, a used engine is likely a better option. I'd expect $3,000 - $4,500 parts and labor, and that's finding a NICE indy that won't bend you over on trying to stack labor for swapping over the parts you've already replaced, or if the longblock comes bare.

I agree with fmorelli as for the failure. When you took it to the indy shop, did you tell them you thought you spun a bearing and wanted them to confirm it, or did you just drop it off saying it had a noise? Did they charge you for said diagnostic?

I think you're in for a $4,000ish bill in any scenario here. Replace the motor to get it running, or sell it as is. You'll likely take an even bigger hit selling it as is, if you owe $9K still. I'd expect you'd get $4,000 tops for it with the knocking motor, and that's if everything else is tip top.

With these cars, you either need to really DIY stuff, or have an extended warranty, or a BIG checkbook.
 

Milan

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Buy a used engine and swap it in, wont be too much money. Sell your motor on CL to recover some of the costs. If you are mechanically inclined you can do it yourself with some patience
 

fmorelli

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May I ask where you are located and who the Indy shop is? 70k miles, nothing in the motor should be worn out. Not sure what exactly failed or why (how is the car configured ... any explanation behind the failure?) Did the Indy's look at the oil? Oil analysis?
I agree with fmorelli as for the failure. When you took it to the indy shop, did you tell them you thought you spun a bearing and wanted them to confirm it, or did you just drop it off saying it had a noise? Did they charge you for said diagnostic?
The reason I asked is that I feel this thread is jumping to a whole lot of postulations and conclusions with a ton of data lacking. If I don't know who did the analysis, their conclusions, their competency, I'm not going to go assuming spun bearing / engine replacement / rebuild / et cetera. It would be helpful to know more particulars, to a level that convinces that we have a solid diagnostic. It would also be helpful to know if the Indy shop is one that has a reputation for working on BMWs and can guide the OP (or not). I don't even know the level of the OPs knowledge/experience/skill - this was his 3rd post on Spoolstreet - and so knowing more about that would also help in providing feedback.

Filippo
 
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Rob09msport

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The reason I asked is that I feel this thread is jumping to a whole lot of postulations and conclusions with a ton of data lacking. If I don't know who did the analysis, their conclusions, their competency, I'm not going to go assuming spun bearing / engine replacement / rebuild / et cetera. It would be helpful to know more particulars, to a level that convinces that we have a solid diagnostic. It would also be helpful to know if the Indy shop is one that has a reputation for working on BMWs and can guide the OP (or not). I don't even know the level of the OPs knowledge/experience/skill - this was his 3rd post on Spoolstreet - and so knowing more about that would also help in providing feedback.

Filippo
Makes really good point spun bearing usually more of hollow knock sound at high load low rpm and idle that in early stages usually gets quieter as revs increase and is loudest at startup. Could you post video of cold start and after 30 sec slowly increase rpm in park/ neutral .
 

RSL

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Recently saw someone else that diagnosed rod knock based on YouTube vids and it turned out just to be a loose PS pulley.

Sucks if it is rod knock, but I wouldn't spend a dime to start swapping motors or rebuilding one without being 100% sure. At the very least, do some actual diagnostic work: check the oil (and pullies) or even better, pull things apart to actually verify.
 
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Sshec152

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Recently saw someone else that diagnosed rod knock based on YouTube vids and it turned out just to be a loose PS pulley.

Sucks if it is rod knock, but I wouldn't spend a dime to start swapping motors or rebuilding one without being 100% sure. At the very least, do some actual diagnostic work: check the oil (and pullies) or even better, pull things apart to actually verify.
That happened to me as well, i thought the motor was toast, then it actually got worse but would change pitch when turning the steering wheel, found the power steering pump bolts were loose.
 
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RSL

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That happened to me as well, i thought the motor was toast, then it actually got worse but would change pitch when turning the steering wheel, found the stteering oump bolts were loose.
I'll bet that was a relief. If my car ever started making noises like that, I wouldn't be able to sleep until I found out what the source was.
 
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Rob09msport

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Can't imagine how people felt before we knew wastegate rattle was issue with these cars that can sound like valve train saying bye bye
I had heart attack when my pressure converter went lol I'm a big bitch when comes to noises cause with my luck it's usually expensive and my ocd never lets me just turn on radio instead i roll down windows and look for probs that most time i imagine
 
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Matt's 08 335i

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Hey everyone thanks again for the reply’s. My car is just sitting for the most part, haven’t had the time yet to take it somewhere else. I uploaded a video to YouTube of the car after it had been driven for about 30mins, so everything is to temp. I will upload a cold start soon but you dont really hear it from a cold start at idle, or in general you don't here the knock at idle. So in the video I am holding the throttle at 2k in order to really here the knock. I hold it at 2k and rev it up so that you could here it at a higher RPM, and towards the end the engine is just at idle. I wanna say that it kinda goes away as rmp increased, as in its not so loud of a knock. I've bought this car at 36k miles. Since owning it I've only had the JB4 and duel cone intakes, and that was probably around 45k when I bought the JB4 and installed it. I have never had anything else performance wise. I have never ran E85 as well, change my oil about around every 10K miles. For the most part this car has been pretty stock.
Here's a link to the video.
 

fmorelli

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Sorry to hear you are having this problem. With that said I'm going to leave this thread. I won't speculate whether a motor is trashed based on a video. I understand that you may not wish to answer the questions I asked. I wish you the best of luck with your car. Hopefully it is something minor.

Filippo
 

Rob09msport

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Sorry to hear you are having this problem. With that said I'm going to leave this thread. I won't speculate whether a motor is trashed based on a video. I understand that you may not wish to answer the questions I asked. I wish you the best of luck with your car. Hopefully it is something minor.

Filippo
Filippo is a really smart guy that can diy everything. Like he said without history it's hard but that isn't a very common problem on low mileage unless something was abused or not maintained. Rod knock is when the metal wears and creates too much clearance so under high load "torque not hp" it slaps around that's why up hill high gear lugging will be loudest. But unless taking apart engine no one could tell me to spend the money needed to fix this without checking oil , at the least pull filter and shine light on it in dark room looking for metal. Trust me we would all love to say it's not the prob but don't want make you cause more damage but also most will tell you not waste the money without being sure. An oil analysis is cheap and will give you time to explore options and prepare for worst hope for best
 

langsbr

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30 bucks for an oil analysis might yield some valuable info, even if it's not bearings.
 

Torgus

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Do what you do with a sick horse, sell it to someone else.

Seriously. Sell/Trade it to a dealership, when they sell it to someone else they get a free motor(in theory) after they take it back for a bad engine and it's under 90 day warranty or whatever. Or whatever, it's not your problem at that point.