N47 2.0d X3 Metallic Rattle - Bottom End

[noodlemonkey]

Good Day everyone, Let me start by saying, I really hope someone here can help - I've been struggling for nearly a year on this issue,

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My engine makes a metallic rattling sound only when HOT - nice and quiet during cold start up,
Engine Mileage 150k

A little history on this engine:
- Cracked the block - Replaced with Recon block
- Engine Builder at the time installed incorrect journal bearings - Spun journal bearing no.4
- Crank cut 10thou
- Correct bearings installed
- Timing chain set replaced and aligned correctly
- All other filters and goodies were replaced,

Prior to the spun bearing - Engine Sounded AMAZING, incredibly quiet

Can anyone shed some light - I have pictures of nearly everything, so let me know what you want to see.

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Another Engine Builder (Mike Dixon) which has been assisting me during this process suspects that the oil/vac pump combo could be the issue as the noise is coming from the Far back side(gearbox side) of the oil pan...

 

[Solo Man]

Did you replace the dampener pulley on the crank as well. Sounds like you could have a cracked pulley. About R4k for replacement from Goldwagen!

 

[noodlemonkey]

Did you replace the dampener pulley on the crank as well. Sounds like you could have a cracked pulley. About R4k for replacement from Goldwagen!

Hi Solo Man - I haven't replaced the pulley - What makes you believe its the pulley?

 

[Solo Man]

On my E83 X3 2l diesel i had this funny noise (difficult to describe) but also rather metallic which turned out to be the dampener pulley which was cracked. I noticed the sound for quite a while and eventually coming back from Hartenbos with my caravan in tow the aircon belt came off. I thought at first that the a/c gas was low but when i got home i noticed the belt lying on the plastic splash plate below the engine and noticed the dampener pulley is wobbling. The sound would come and go but thinking back it could be that it was quiet when cold and tapping when hot?? Take a mirror and flashlight and have a look at yours.

 

[mahome1]

Hi

I have a 2013 BMW x3 20d. Had a similar noise which turned out to be a Transfer case Mounting (BMW Calls it a Bush). replaced and no issues thereafter.

 

[cOlDFuSiOn]

Just replaced Pulleys on my F30 335i, similar sounding noise.. Check them first.. :thumbs:

 

[noodlemonkey]

Thanks Everyone - The noise is coming from the sump - right at the back of the sump(oil Pan),

I'll check the transfer case mount as @mahome1 said,
Will check if the crank pulley is wobbling around,

Thanks

 

[noodlemonkey]

Crank pulley is not moving around in any direction and the Gearbox/Transfer case mount is Rock solid...

Anyone Spun a journal bearing so badly that is banged the Conrod 4thou Oval?

We suspect Piston Damage as that was the only item within Cyl no.4 which wasn't replaced.

Any takers on the theory?

 

[noodlemonkey]

UPDATE:

Problem Found - Warn out Small bush on conrod no.4 - Causing the piston to float to much, which caused it to lightly touch the intake valves.

All 4 conrods have been re-bushed on the small end's

Thanks for everyones input