Ticking or Rattling noise from Engine

Abstract: Ticking or Rattling noise from Engine during cold start or short trip


Applies to: BMW 3 Series 2006-2009(E90, E91, E92, and E93 with the N51, N52 or N52K engines)


Let me know how it works for you. Comment below on changes that would improve the article, whether it works for you, etc. - Nick

An occasional ticking or rattling noise from the intermittent hydraulic valve adjuster (HVA) elements may occur during cold engine starts or frequent short-distance driving. In these situations, the HVA elements may not yet have been supplied with sufficient amounts of air-free oil. This condition will not cause any
damage to the engine, and usually remedies itself with a longer driving distance or operating times at full operating temperature.

HVA bleeding procedure:

The bleed time may take anywhere from between two minutes and (in rare cases) to a maximum of 30 minutes. This procedure is to be performed
on a level surface with the vehicle stationary, and in a properly ventilated area.

Before performing HVA bleeding procedure chack that:
*Engine oil level is correct
*Engine is at operating temperature

-Bring the engine up to an operating speed (no load) of 2000-3000 rpm and maintain this condition for three 1. minutes (bleeding procedure).
Let the engine idle for 15-30 seconds and reevaluate whether the noise is still present or not.

-Engine quiet - procedure is finished.

-Engine noise is still present - repeat the procedure; perform steps #1 3. and #2 up to a maximum of 5 times.

-Only if the noise remains after performing the bleeding procedure 5 times: proceed by performing the procedure for a final time, also at an
engine operating speed of 2000-3000 rpm, but for a total time duration of 15 minutes.

If bleeding procedure is unsuccessful or ticking noise returns shortly after HVA bleeding procedure cylinder head replacement may be necessary.

Before Performing any Work

Please read Cautions and Warnings before proceeding with any work on your vehicle

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