Vibration during idle

[Red_Bean_Bun]

Unfortunately now my 08 X6 has the same symptom. Changed everything and it does not work, next servicing will consider thicker oil perhaps 10w40.

Injectors changed ?

 

[Barrudas]

An update to this thread. As I wanted to be sure so I went to diagnose my car at a few workshops. But the results all differ so I'm feeling a little frustrated. These are the diagnostic results
1. Valve cover diaphragm tear (oil separator) which causes high vacuum pressure inside the valve cover resulting in rough idle.
2. Entire exhaust is slightly bend because I hit a stone before and is causing the vibration
3. Third results comes from a compression test I did where my fourth cylinder measure a lower pressure (25 lesser than the benchmark 150/without oil & 170 with oil) which might indicate of my my valve might be leaking due to wear and tear.

As it has been a very expensive journey so far so I am going to progressively do the following fixes to try to see if this improve.

Replace valve cover (less than 1k sgd)
Replace exhaust (about 3k sgd)
Engine overhaul again (about 3k sgd)

Depressing. Maybe I should consider changing car


Sent from my iPhone using Tapatalk

 

[Red_Bean_Bun]

An update to this thread. As I wanted to be sure so I went to diagnose my car at a few workshops. But the results all differ so I'm feeling a little frustrated. These are the diagnostic results
1. Valve cover diaphragm tear (oil separator) which causes high vacuum pressure inside the valve cover resulting in rough idle.
2. Entire exhaust is slightly bend because I hit a stone before and is causing the vibration
3. Third results comes from a compression test I did where my fourth cylinder measure a lower pressure (25 lesser than the benchmark 150/without oil & 170 with oil) which might indicate of my my valve might be leaking due to wear and tear.

As it has been a very expensive journey so far so I am going to progressively do the following fixes to try to see if this improve.

Replace valve cover (less than 1k sgd)
Replace exhaust (about 3k sgd)
Engine overhaul again (about 3k sgd)

Depressing. Maybe I should consider changing car


Sent from my iPhone using Tapatalk

Noob at these things but IIRC for item 3 should use the variance between highest and lowest reading as a gauge. And that is only for testing the piston ring. If cylinder reading very low then pour some oil inside then measure again. All that for piston ring wear.

For valves - can use the leak down test. Then hear how.

Exhaust bent or kena dent ? If bent cannot bend back ?

 

[Barrudas]

Noob at these things but IIRC for item 3 should use the variance between highest and lowest reading as a gauge. And that is only for testing the piston ring. If cylinder reading very low then pour some oil inside then measure again. All that for piston ring wear.

For valves - can use the leak down test. Then hear how.

Exhaust bent or kena dent ? If bent cannot bend back ?

I think you are right about the gauging but I don't really know how to explain.

For the exhaust I hit the catalytic converter area and I was told can't bend back.