n57 bad rattle, rod bearings?
Discussion
Girlfriend just came home saying her car is rattling. It does not sound good.
Strangely, I have been doing a lot of reading about BMW rod bearings, particularly in the V8s - I have a car with an S63tu that I'm thinking of keeping hold of for longer than I thought.
My thoughts are that there is a high chance that this is rod bearing failure here. What do you think? I have done a very basic test of unplugging a few injectors (one at a time of course) to compare the current rough-running to a cylinder-down rough running. I just did the front 3 cylinders though due to not being in a position for stripping bits down yet, but I confirmed they are running and that engine is even worse with each of those injectors unplugged.
Video:
I suppose my options are to get whatever tool is required for pulling an injector, and putting a borescope down each cylinder to have a look from the top, and/or pulling the sump and checking the con rod bearings from the bottom.
cheers,
Carl
Strangely, I have been doing a lot of reading about BMW rod bearings, particularly in the V8s - I have a car with an S63tu that I'm thinking of keeping hold of for longer than I thought.
My thoughts are that there is a high chance that this is rod bearing failure here. What do you think? I have done a very basic test of unplugging a few injectors (one at a time of course) to compare the current rough-running to a cylinder-down rough running. I just did the front 3 cylinders though due to not being in a position for stripping bits down yet, but I confirmed they are running and that engine is even worse with each of those injectors unplugged.
Video:
I suppose my options are to get whatever tool is required for pulling an injector, and putting a borescope down each cylinder to have a look from the top, and/or pulling the sump and checking the con rod bearings from the bottom.
cheers,
Carl
marcelN57 said:
I've decided to drop the subframe, take off the oil pan and look at it from below. Hopefully it's just a spun rod bearing and I can get away with replacing that and polishing the crank bearing surface.
Given I'm observing consistent codes for cylinder 5 balance only, I assume most likely it's that rod bearing rather than the pulley / cylinder 1. But we shall see! I'll take it apart this weekend.
Good luck. I have been contemplating the same, however I'm considering just removing the engine and taking my time, after I have checked the oil and oil filter, which will be this weekend.Given I'm observing consistent codes for cylinder 5 balance only, I assume most likely it's that rod bearing rather than the pulley / cylinder 1. But we shall see! I'll take it apart this weekend.
Thanks everyone. Apologies for the radio-silence. I have been frantically getting the stationary M6 road legal and MOTd while she drives my 125d and I talk my way out of work site-visits.
It's been a wonderful week for working on a car outside and being forced to ride motorcycle a couple of times. I feel like I've had a proper holiday from my life of working and endlessly watching people do stuff on youtube. I've been forced and kicked up the arse to do my long term project (get mill running to fix lathe top slide to skim m6 discs). Refitting the cats on the M6 was a crap job as usual and that is the last time I will ever do that job.
I should hopefully start looking at the x4 this weekend.
It's been a wonderful week for working on a car outside and being forced to ride motorcycle a couple of times. I feel like I've had a proper holiday from my life of working and endlessly watching people do stuff on youtube. I've been forced and kicked up the arse to do my long term project (get mill running to fix lathe top slide to skim m6 discs). Refitting the cats on the M6 was a crap job as usual and that is the last time I will ever do that job.
I should hopefully start looking at the x4 this weekend.
Marcel, I will re-post your images for you.
Also, can you give a brief rundown re: dropping subframe - any shortcuts etc. The weather has picked up, so think I will do the same tomorrow. Not sure if yours in an X3/X4 too but would like to hear your experience regardless. I was going to remove bumper and pull engine but it would be good to inspect from below first.
These are MarcelN57's images:
1. Rod bearings - number 5 is spun and pretty destroyed. Rod and rod cap look fairly okay.
2. Main bearings - number 6 has lots of wear and is somewhat distorted. It was also very slightly rotated when I took them out, maybe 3-5 degree, but not so much that it would block the oil flow. It doesn't look like it spun, the outer bearing surfaces look pristine.
Number 2 to 6 are visible in the photo below.
Also, can you give a brief rundown re: dropping subframe - any shortcuts etc. The weather has picked up, so think I will do the same tomorrow. Not sure if yours in an X3/X4 too but would like to hear your experience regardless. I was going to remove bumper and pull engine but it would be good to inspect from below first.
These are MarcelN57's images:
1. Rod bearings - number 5 is spun and pretty destroyed. Rod and rod cap look fairly okay.
2. Main bearings - number 6 has lots of wear and is somewhat distorted. It was also very slightly rotated when I took them out, maybe 3-5 degree, but not so much that it would block the oil flow. It doesn't look like it spun, the outer bearing surfaces look pristine.
Number 2 to 6 are visible in the photo below.
Thanks very much! I do have an engine support bar so I can use that to help.
I've reposted your photos below.
These are MarcelN57's photos:
View from above on all the straps that hold the engine (engine mount) as well as steering rack and stabilizer in place
Sub frame just coming down. It's not too heavy, I did all of this by myself.
View from below with subframe removed
I've reposted your photos below.
These are MarcelN57's photos:
View from above on all the straps that hold the engine (engine mount) as well as steering rack and stabilizer in place
Sub frame just coming down. It's not too heavy, I did all of this by myself.
View from below with subframe removed
marcelN57 said:
Now you have definite confirmation it's not an injector or something like that!
Update from my carnage:
I polished the crank surface for the #5 rod bearing (the bad one), then put that journal back together using the bearing shells from one of the other (good) rods. The plan was to measure the bearing clearance with Plastigage. However - the journal had lots and lots of play. Knock knock
So I took it back apart and measured the crank diameter at #5 rod position. It's between 49.2 and 49.5mm depending where you measure - not round and totally out of spec (49.975 - 49.994)!
Sounds like I need a new crankshaft. Which means, I need to take the engine out. At that point, it also makes sense to replace the #5 connecting rod. Which means, head has to come off... Gone the dream of a quick fix for this.
Oh dear, I'm sorry to hear that. I was hoping you (and I!) would get away with a quick fix.Update from my carnage:
I polished the crank surface for the #5 rod bearing (the bad one), then put that journal back together using the bearing shells from one of the other (good) rods. The plan was to measure the bearing clearance with Plastigage. However - the journal had lots and lots of play. Knock knock
So I took it back apart and measured the crank diameter at #5 rod position. It's between 49.2 and 49.5mm depending where you measure - not round and totally out of spec (49.975 - 49.994)!
Sounds like I need a new crankshaft. Which means, I need to take the engine out. At that point, it also makes sense to replace the #5 connecting rod. Which means, head has to come off... Gone the dream of a quick fix for this.
I pulled pan on mine, oil was like black gloop. When I washed away the gloopy oil in the pan, I saw lots of beautiful glitter.
You can get a new forged crank from Autodoc for ~$1200 USD. Non-OEM but also not Aliexpress. You can also get one from Ali Express for half that :-) that won't be forged though.
Good stuff. Thanks for the update, I'm looking forward to following along.
Our engine is nearly out. I was stopped by the rain, and I couldn't find a wiper-puller for getting the rear cowling off the car. Hopefully I'll carry on this weekend.
It's looking very sorry for itself :-)
Our engine is nearly out. I was stopped by the rain, and I couldn't find a wiper-puller for getting the rear cowling off the car. Hopefully I'll carry on this weekend.
It's looking very sorry for itself :-)
Edited by carl0s on Wednesday 29th May 10:56
How're you getting on?
I finally got our engine onto a stand in the garage today. I pulled the engine and trans a few weeks ago and got it down into the garage, but have only today mounted it to the stand the turned it upside down.
I haven't removed caps yet but I can rattle rod caps 1 to 4 and they have probably 1mm of wobble/rattle in them, which does not look good at all. 5 and 6 are the only ones without the wobble.
I finally got our engine onto a stand in the garage today. I pulled the engine and trans a few weeks ago and got it down into the garage, but have only today mounted it to the stand the turned it upside down.
I haven't removed caps yet but I can rattle rod caps 1 to 4 and they have probably 1mm of wobble/rattle in them, which does not look good at all. 5 and 6 are the only ones without the wobble.
BlueMR2 said:
At the end of the video the dash did seem to state it was 2 years late for a service.
However considering you are happy pulling an engine to bits, I'd imagine you would do the oil yourself but perhaps not be able to update the computer.
It's my girlfriend's car and she definitely missed the last service, and the one before that was a 'we pick it up and return it to you all done' and I have my doubts what they did..However considering you are happy pulling an engine to bits, I'd imagine you would do the oil yourself but perhaps not be able to update the computer.
Historically she didn't seem too eager for me to mess with her pride and joy but I think we're beyond that now. I did keep telling her that she really ought to get her service booked in but it fell on deaf ears
That is some impressive work Marcel. I can't believe how clean everything looks.
The vibration thing, it's not like a thud-thud-thud in the back while accelerating is it? We had that on this X4. It was hard to tell that it wasn't just bumps in the road at first, but I thought something was wrong, and it gradually got worse. I realised it was probably the transfer case, and I went down the rabbit hole of measuring overall wheel/tyre diameters, and pricing up new/refurb transfer cases. In the end I did an oil change on the transfer case. I put in some Ravenol TF-0870, and it solved it. I suppose your issue might only be this if you happen to have lost some fluid during the strip down, otherwise as you say it's probably front axles.
My mum's Golf had a bad CV joint and I made the mistake of replacing both sides with non-OEM Chinese driveshafts, and then when I put it back together and went for a drive, the car had a vibration at 3,700rpm, (which I didn't know hadn't been there before because all I could hear before was a clacking CV joint!).
I ended up changing out the clutch and flywheel (DMF), and an engine mount I think, only to later realise that one of the Chinese driveshafts was junk - they used the same solid tube on both sides whereas OEM is hollow and wider diameter on the longer side ( https://www.mig-welding.co.uk/forum/threads/cv-joi... )
Hope your new driveshafts are good quality :-)
The vibration thing, it's not like a thud-thud-thud in the back while accelerating is it? We had that on this X4. It was hard to tell that it wasn't just bumps in the road at first, but I thought something was wrong, and it gradually got worse. I realised it was probably the transfer case, and I went down the rabbit hole of measuring overall wheel/tyre diameters, and pricing up new/refurb transfer cases. In the end I did an oil change on the transfer case. I put in some Ravenol TF-0870, and it solved it. I suppose your issue might only be this if you happen to have lost some fluid during the strip down, otherwise as you say it's probably front axles.
My mum's Golf had a bad CV joint and I made the mistake of replacing both sides with non-OEM Chinese driveshafts, and then when I put it back together and went for a drive, the car had a vibration at 3,700rpm, (which I didn't know hadn't been there before because all I could hear before was a clacking CV joint!).
I ended up changing out the clutch and flywheel (DMF), and an engine mount I think, only to later realise that one of the Chinese driveshafts was junk - they used the same solid tube on both sides whereas OEM is hollow and wider diameter on the longer side ( https://www.mig-welding.co.uk/forum/threads/cv-joi... )
Hope your new driveshafts are good quality :-)
marcelN57 said:
Thanks Carlos!
I used this degreaser diluted about 50:50, a brush and a pump sprayer to clean most of the parts. Took some time but worked pretty good!
Interesting with the transfer case noise. It's coming from the front in my case, and of the front drive parts, the CV axles are the ones that had to suffer the most / any abuse in this project because they were constantly in the way, so I assume it's them.
I ordered these from GKN - made in Spain and supposedly OE quality. Let's see!
Thanks very much for the degreaser tips.I used this degreaser diluted about 50:50, a brush and a pump sprayer to clean most of the parts. Took some time but worked pretty good!
Interesting with the transfer case noise. It's coming from the front in my case, and of the front drive parts, the CV axles are the ones that had to suffer the most / any abuse in this project because they were constantly in the way, so I assume it's them.
I ordered these from GKN - made in Spain and supposedly OE quality. Let's see!
Oh yes those are top notch driveshafts. You are into a few dollars here for sure :-)
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