AI001

I noticed while coming to a halt after finishing a short journey (20 minutes round trip) in my 535d LCI (2007 MY with 40k on the clock) there is a metallic ticking noise coming from underside. I remember the night before also it was making this noise. Its like tick tick tick at 1 sec interval coming from area around exhaust pipe. I recorded that ticking and will post it here from home.

I started driving again but this time I connected my DIS and checked DDE data and said DPF regeneration active after around 5 minutes of driving. It was active for 10-15 minute while I drove around town (no fast speed just upto 30-40mph) car was keeping in high gear, once regen done everything was back to normal. I wonder why would it make ticking sound while doing regen. Exhaust temperature was quite high like 450C+ and engine temp like 92-93. Does your car making ticking noise too while regen?

I did replace EGR stat due to car not reaching full operating temperature and since then its like on 86-90C but I generally make short journeys. I am not sure if regen process was fully complete ever. I am sure it tried regen a night before and then again next day I drove which finally finished and regen counter reset. I will keep in eye on next regen if this happens quite often I have something wrong in DPF area.

No fault code present though.

Rez

I hear ticking/ rattling noise from below the engine. It happens right after starting kept at idle while warming up. It is at a faster pace than 1 second intervals, and last about 10 seconds.

AI001

I don't know if the noise is coming while driving the car as its not that high noise and not linked to engine rev. I only find it if engine is stopped, not linked to engine speed at all.

Snitzl5

i have a ticking sound as well. I did some searching and found a lot of talk about it and even a service bulletin. Its called the Intermittent Hydraulic Valve Adjuster (HVA) Noise. From the bulletin "An occasional ticking or rattling noise from the camshaft hydraulic valve lifters (HVA) may occur during cold engine starts, due to frequent short-distance driving, or the noise may occur for an extended period of time even though the engine is at operating temperature." I've attached the pdf bulletin for you to check out. Hope this helps

SIB_110907 Engine tick HVA Noise1.pdf

AI001

Mine is M57N2 diesel so this SIB doesn't seem to be relevant here. Thanks for sharing. Its no rattling noise I don't feel anything inside the cabin, either its in way back the tail pipe or only ticking when engine is off.

I will wait for this to happen next and then keep the engine running and see if not noise still present or goes away.

KAF

Mine does this regularly, I have always assumed it is metal expansion/contraction in the exhaust system.

Never worried about it.

Snitzl5

Oops my bad bro