engine noise 4.4 Help!

[esoup]

Hi Everyone,

This is my first X5 and first V8 BMW. It is a 2002 4.4 with approx. 75k miles on it. I bought it in October with about 70k miles and was in pristine condition and thoroughly inspected by Erhard BMW in Michigan. At approx 72k miles I changed the oil with Castrol 5W30 as per BMW. After the oil change i began to notice a slight knocking sound. I only occurs after the engine reaches operating temperature and only on idle. Off idle around 1000rpm there is no sound whatsoever. I went to a highly reputable independant garage for a quick listen as was told not to worry: everything sounded fine. they suggested 5w40 however. Today I changed the oil with 5w40 but am still hearing this noise. It is more prevalent on the passenger side and if you put your hand on the valve cover you can feel more vibration compared to the opposite side. With the hvac and radio off you can hear it in the cabin at a set of lights. It's not terrible just something that was definately not there (or disguised) when I bought it. Any help or insight would be greatly appreciated. I have only owned the inline 6's and am now wondering if i should have sticked with them.

[Tomaz]

More than likely a valve lifter. They can become leaky or the oil port clogged. You may want a professional opinion, but it could become expensive. My lifters knock slightly at idle too when cold. (90K 0n my 01' 4.4) Generally, it is not hurting anything. At idle the sound is just the lifter contacting the cam, over 1000 rpm the speed overcomes the leak and the lifter tightens up. Next oil change try Amsiol 5w -30 which I am told is a thicker oil. Good luck

[wheelman]

Same noise with mine and yes its the lifters. Was told the same deal as well. Not to worry. It does bug me though....

[esoup]

...just wondering if it is a lifter, would the noise not be more prevalent when cold? does your noise quiet down when reaching operating temperature? mine is perfect when cold, even at -20C then begins to rap.

[sp33dd3m0n90]

Originally Posted by Tomaz

More than likely a valve lifter. They can become leaky or the oil port clogged. You may want a professional opinion, but it could become expensive. My lifters knock slightly at idle too when cold. (90K 0n my 01' 4.4) Generally, it is not hurting anything. At idle the sound is just the lifter contacting the cam, over 1000 rpm the speed overcomes the leak and the lifter tightens up. Next oil change try Amsiol 5w -30 which I am told is a thicker oil. Good luck