I think that I solve this problem. Problem was insidiously vacum leak on brake booster hose. I put new hose in January and to this days, idle is fine.

DHFiS wrote: ↑

Wed Oct 27, 2021 9:26 pm

I had one noisy lifter and within minutes of an oil change with 10/40 it was cured.

Liqui moly 10w40 MOS2. Best oil for M40/M42.

twright wrote: ↑

Thu Dec 09, 2021 12:14 am

Just because your ICV is clean, doesn't mean it works. I'd try a new one. There are inexpensive aftermarket ones.

I was thinking about that.

Idle last day and today was perfect. But just like I said in first post, suprise with stalling is posible...

So, my E30 M40 last night stalling in traffic when idle. Then I start up engine again and idle is perfect. Also today, idle is perfect. Sometimes idle is great for a long time than again, I have problem like last night. Start engine again and everything is normal. ICV is clean, MAF boot is new, hose...

Problem solved! Adjusting pulley was overtightened. But on M40 engine there is a little hole on timing belt cover and you can through her adjust pulley/timing belt with hex key, without remove up/down timing belt cover casing. It is cover/hole number 13 on link, http://bmwfans.info/parts-catalog/E30...

Is it possible that timing belt is overtightened ? Last week mechanic replace timing belt on my E30.

Here is the video :

https://youtube.com/shorts/G16T5Puus9c?feature=share

Hello E30 fans! Last days I noticed that original timing belt which was built-in E30 M40 engine had width 19 mm. But when you check in EPC timing belt for BMW E36 M40 model, width was 20,7 mm. That "newer" timing belt you can fit on E30 M40 model also. My question is : Is it possible that BMW made s...