[Oberumen]

This is 2014 428i xdrive with 110,000 miles. N20 engine.
-No tunes
-no codes except a "drive train malfunction" message when the car was on idle (this only happened once, that same day I stop driving the car)
I've owned this car for just a little over a year and spark plugs where fine when we checked them then. Never serviced the injectors.

This past weekend my mechanic listened to the sound with a Mechanic's Stethoscope and could tell the rattle/knocking was coming from the passengers side of the engine and it was a lot louder around the turbo so we thought it would be a good idea to change the watergate and the turbo thinking it would fix the problem but it didn't.

Then I made the decision to remove the valve cover to check the timing chain. Turns out the timing chain guide is broken where it clips. This would probably explain the whining noise I began hearing for the last couple of months. After this we decided to remove the oil and check for metal particles, which there were. So according to him he suggests we just get a new engine because bad Rods are probably the reason is knocking.

I sense there is something else going on and it's not the Rods but perhaps something on the top of the engine making this knocking noise. Any suggestions? Before I make the decision to get another engine?
I'll leave the link to the video below.

[zeikei]

Sounds like rod knock to me.

[MHF30]

I might be wrong here, but it kinda also sounds like you have the high pitch whine of a impending timing chain issue as well. Might want to get the car checked out before you run into a bigger problem.

[Oberumen]

Originally Posted by MHF30

I might be wrong here, but it kinda also sounds like you have the high pitch whine of a impending timing chain issue as well. Might want to get the car checked out before you run into a bigger problem.

After opening the valve cover and seeing that timing chain guide was broken. I was hoping replacing it might fix the issue. But I know how time consuming and costly it will be. If that does not fix the issue then it will be just a waste of money and time. Could it be the time chain is making this noise? Or it's too loud to be that?

[MHF30]

Originally Posted by Oberumen

After opening the valve cover and seeing that timing chain guide was broken. I was hoping replacing it might fix the issue. But I know how time consuming and costly it will be. If that does not fix the issue then it will be just a waste of money and time. Could it be the time chain is making this noise? Or it's too loud to be that?

I can't say if it will fix the knocking issue or not, but definitely do not drive the car with a broken guide. You can cause serious damage and could end up blowing the engine. At a good indy shop, it'll cost you around $3-4k to get the timing chain work done.

[Billfitz]

That's timing chain and more. The cost to fix that engine probably exceeds its worth.

[Wires]

That is just a lot of sadness in that block. Could be the timing chain jumped and now the pistons are hitting the valves.

Really hard to guess without digging in deeper, but my guess is you have a paperweight.

[celticfc]

That is a combination of rod knock and timing chain. Given that you have already found the chain guide to be broken (the Achilles heel of the N20) and the death knoll of the whining timing chain it makes zero sense to do just the chain. There are most likely broken pieces of the guide in the oil pump which would contribute to the oil starvation to the rod/rods. As previously mentioned the cost to fix it will be more than it is worth. However, check our the N20/N26 Class Action Lawsuit thread, hopefully your vehicle will fall within the claim parameters and you get it repaired under warranty.

[Billfitz]

At 110,000 miles he'd get zilch.

[Wires]

Yeh, age plus driving around for a couple months with the broken guide does it no good.

[Oberumen]

Originally Posted by oluedo

When driving, does it seem to come from under the center console?

When I first heard this, i thought the noise was coming from the exhaust, not the front of the engine. So I guess it did.

[oluedo]

I had a similar sound and it was the brake cable clip that was broken. There was rattling against the drive shaft. Had to be replaced.

[oluedo]

Had the idea to look into it after seeing this page. They were right. You could compare the sounds.
https://f30.bimmerpost.com/forums/sh....php?t=1574489

[thejeremyman9]

Originally Posted by oluedo

I had a similar sound and it was the brake cable clip that was broken. There was rattling against the drive shaft. Had to be replaced.

This is totally different. I had the cable break and not only is the sound totally different but that issue doesn't happen in neutral...

[Wires]

Originally Posted by oluedo

I had a similar sound and it was the brake cable clip that was broken. There was rattling against the drive shaft. Had to be replaced.

He said his mechanic used a stethoscope to listen to the block. You can 100% pinpoint location of sound with that. And then couple in that death whine says it's more than a clip.

[Oberumen]

Attached is a photo of the timing guide not clipped.
Could this be the reason of the "knock" maybe the chain is slapping against it when the car is revved up because it's not in place as it should?

[m1256]

That doesn't look good at all.

[chrism9852]

The knock is absolutely your oil starved rod bearings. the busted/pulverized guides are in bits in your oil pick up tube.

The only saving of that engine is a total rebuild which is wholly cost prohibitive unless using the exercise as a learning experience.

Also that photo is not all in focus, but there look like metal shavings in there.

[m1256]

What's the build date on the door tag ?

[Xplict]

In my case I have an N55, while revving at 1.5k rpm it starts knocking. My mechanic believes it’s a broken timing chain guide. The engine is at 129k miles

https://youtube.com/shorts/dLCUIPE3jIM?feature=share

Let me know your thoughts on what this could be, thank you ahead of time!

[Billfitz]

Originally Posted by Xplict

In my case I have an N55, while revving at 1.5k rpm it starts knocking. My mechanic believes it’s a broken timing chain guide. The engine is at 129k miles

That's not timing chain, which is a loud whine that varies in pitch with revs. My assumption is that your mechanic is aware that guides can fail but doesn't know the symptom. That slapping noise isn't it.