E92 M3 S65 – Loud ticking + metal in oil + rebore 2 years ago – Repair or Sell?

[yillan_h]

Hi everyone,
I’m reaching out for experienced advice on my 2010 E92 M3 (S65 V8 + DCT). I really want to keep this car long-term (10+ years or for life), gradually mod it, and maintain it well — but I’m worried the engine may have ongoing issues.

Car basics:

Mileage: 140000 km
Previous owner did a major engine rebuild ~2 years ago, (causes unclear) including full cylinder rebore (oversize bore + new pistons/rings).

Big concern about the rebore:
I have no details on the shop, bore size, crank condition, or how they handled the Alusil coating. High-rev S65 rebuilds with boring are still quite rare in China, and I’m not confident the shop followed the precise tolerances and procedures that experienced builders in the US/Europe use. This makes me nervous about long-term reliability.

The big rebuilt and service include:
- ACL bearings
- Valve cover gaskets, intake manifold gaskets, oil pan gasket, VANOS seals
- Throttle actuators (ACDL), various seals (crankshaft, camshaft, oil pump, etc.)
- EGR gasket, exhaust manifold gasket, catalytic converter heat shields
- Oil filter housing, oil cooler lines, thermostat, coolant hoses
- Most recent: crankshaft pulley, belts, pulleys, and more seals.
- and the rebore

Current symptoms (videos attached):

Loud high-frequency ticking (“tatatatata”) at idle — cold and hot. It’s now quite noticeable even with hood closed, doesn’t disappear after driving, and is slightly louder when hot.
Recent oil change showed visible fine metal particles (more than just light sheen).
Borescope: very light, minor scoring (“cat scratches”) on cylinder walls.
CEL for O2 sensor (separate issue).

Videos:
Cold start + idle; Hot idle; Rev to ~3000 rpm

My goal:
I love the car — i just have connection to it and i feel it breathe and roar with me on the mountain roads. I want to keep it long-term, add mods gradually (exhaust, tune, etc.), and maintain it properly. But I’m torn: is the engine still savable for reliable long-term use, or will it keep having problems?


Questions:
- Is it possible to make some diagnosis based on the sound and video? What likely is the issue?
- With the rebore history + loud ticking + metal in oil, is this engine realistically worth repairing for 5–10+ years of ownership?
- How can I check/evaluate whether the rebore was done properly (especially since it was in China where S65 experience is limited)?
- Repair cost vs. selling and buying another car with clean bearing/rebore history — what would you do?
- Some even suggest me getting a new/used engine since the car otherwise is in pretty good shape. But how can I be assured that the engine coming in won't have some hidden issues?

I’d really appreciate input from people who’ve dealt with rebored S65s, ticking issues, or metal in oil. Thank you so much!

[RocketyMan]

Sounds to me like lazy lifter.

[RocketyMan]

I'm thinking this.

https://www.bimmerworld.com/Engine/C...0-E92-E93.html

[///M Power-Belgium]

yillan_h

That is not rod knock in your video.

That's a very noisy S65 valve train ticking aka. the S65/S85 sewing machine noise.
You should run it with the original/recommended BMW ///M Twin Power Turbo 10W-60 Engine Oil.
That will make it much quieter (!)

[yillan_h]

Originally Posted by RocketyMan

I'm thinking this.

https://www.bimmerworld.com/Engine/C...0-E92-E93.html

thanks a lot! will be a quick fix if this is it!

any way you'd think i can diagnose this more surely without taking the engine apart? would be great to be able to tell before next steps

[yillan_h]

Originally Posted by ///M Power-Belgium

yillan_h

That is not rod knock in your video.

That's a very noisy S65 valve train ticking aka. the S65/S85 sewing machine noise.
You should run it with the original/recommended BMW ///M Twin Power Turbo 10W-60 Engine Oil.
That will make it much quieter (!)

thanks mate. would be great if this is just about oil ! but i will get a full oil change first to see how it goes.

i've been using the original 10w-60 but it's been at least 2000km, and over the 2000km, it burned like half a liter, which is normal i presume?

[///M Power-Belgium]

Originally Posted by yillan_h

thanks mate. would be great if this is just about oil ! but i will get a full oil change first to see how it goes.

i've been using the original 10w-60 but it's been at least 2000km, and over the 2000km, it burned like half a liter, which is normal i presume?

Yeah , normal . Half liter is normal if you pushed it in the high rpm's ..

[sergbaja5t]

That sounds like cold piston slap. Me JE pistoned Mitsu did this when cold.

[yillan_h]

Originally Posted by sergbaja5t

That sounds like cold piston slap. Me JE pistoned Mitsu did this when cold.

but mine actually sounds louder when hot post run... so i guess it's not just that. likely some p-w clearance issue due to ring wear etc. or plus more?