What is that kik-tik sound?

[Akhil]

Hi guys,
I got a problem on my 92 525i (152,000 Miles) started a weird sound for past few days. Its kinda kit-kit-kit-……. Sound which is very clear audible when idling, and goes on faster with RPM. I tried to hear where its coming from but could not find what is causing it, but its coming form some where at top of engine. Additionally, when I start my engine in morning (when engine is cold) then I don’t get this sound until I drive at least 5 miles(until engine get hot). Can any one of you guys suggest me where should I start looking and what are usual suspects in this kind of symptom?

Thanks a lot
Akhil

[piman]

Do a valve lash adjustment is all you can do. And even then it still tics.

[Akhil]

But I don’t understand that why do it start tik sound after engine gets hot (not just worm)? Is this something related to oil thickness? Before my last oil change I always used 15W40 or 20W50 (conventional) but I never had this problem, last oil change I used Mobil1 0W40 synthetic (about 1000 mile ago) and now I am getting this sound. Could it be related to my oil?

Thanks
Akhil

[632 Regal]

it could be but I think it has a lot more to do with your valve adjustment and the thicker stuff was a bandaid.

But I don’t understand that why do it start tik sound after engine gets hot (not just worm)? Is this something related to oil thickness? Before my last oil change I always used 15W40 or 20W50 (conventional) but I never had this problem, last oil change I used Mobil1 0W40 synthetic (about 1000 mile ago) and now I am getting this sound. Could it be related to my oil?

Thanks
Akhil

[Alexlind123]

It could be an injector.

[SharkmanBMW]

it could be but I think it has a lot more to do with your valve adjustment and the thicker stuff was a bandaid.

key word, bandaid... now your problem becomes apparent.

[Jon K]

can 100% be injector click

You can't adjust M50 valves.

[Alexlind123]

You probably want to get your injectors checked out ASAP, a sticking injector could burn a valve.

[Rustam]

But I don’t understand that why do it start tik sound after engine gets hot (not just worm)? Is this something related to oil thickness? Before my last oil change I always used 15W40 or 20W50 (conventional) but I never had this problem, last oil change I used Mobil1 0W40 synthetic (about 1000 mile ago) and now I am getting this sound. Could it be related to my oil?

Thanks
Akhil

Your car uses hydraulic lifters for the rockers - that is the reason why the valves do not need valve adjustment. Those lifters get filled with oil. They perform valve adjustment in real time, every moment the engine runs. So the oil is a relevant element in affecting the ticking sound...

I guess for some reason the oil pressure drops when the engine heats up, not allowing the lifters to use as much oil as they need to continually adjust to the valves.

[Akhil]

Alexlind123 could be right, the location of tik sounds is very close to injectors or fule pressure regulator (closest to 6th cyl.), But I don't know what how injectors work so can't be sure. Is there any moving parts in injector which can cause this sound? And if it is injector, shouldn't that cause same sound always, irrespective of engine temp. ? How can I test injector?

Thanks
Akhil