Rod Bearing Issues(N55 E90)

bmw335i · 06-01-2024, 05:21 AM

I went on a drive taking videos drive was safe. Turn the car off and on about four times at a few stops.

Once I got about a mile is away from my house I pulled over to get food and noticed a knock(rod). Then I sat still and noticed it was gone. Continued to rev the car and it came back.

It was only a mile away from my house so can the issue be new engine serious? How would I know if it is new engine serious ? If it’s the rod bearings how can I check myself ?

Dynamics99 · 06-09-2024, 07:56 PM

Drop the pan and check if any bearings spun. If the noise is coming from the top it could be a stuck valve, or piston slap which I doubt. Early N55s are known to eat bearings. If the bearings are spun either rebuild or drop in another motor but do replace the rod bearings on the new motor before you drop in and stick to low-interval oil changes (3.5k-5k intervals).

06-01-2024, 05:21 AM	#1
bmw335i Registered 0 Rep 2 Posts Drives: N55 335i E90 Join Date: Jun 2024 Location: Los Angeles iTrader: (0)	Rod Bearing Issues(N55 E90) I went on a drive taking videos drive was safe. Turn the car off and on about four times at a few stops. Once I got about a mile is away from my house I pulled over to get food and noticed a knock(rod). Then I sat still and noticed it was gone. Continued to rev the car and it came back. It was only a mile away from my house so can the issue be new engine serious? How would I know if it is new engine serious ? If it’s the rod bearings how can I check myself ?
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06-09-2024, 07:56 PM	#2
Dynamics99 Private First Class 38 Rep 179 Posts Drives: 2011 E92 & E90 335i 6MT MSport Join Date: Oct 2019 Location: Philadelphia iTrader: (0)	Drop the pan and check if any bearings spun. If the noise is coming from the top it could be a stuck valve, or piston slap which I doubt. Early N55s are known to eat bearings. If the bearings are spun either rebuild or drop in another motor but do replace the rod bearings on the new motor before you drop in and stick to low-interval oil changes (3.5k-5k intervals).
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