Pulsating noise at idle please Help!

[SpeedsterBek]

Hello all,
I have 5spd 525i with an M50 engine. Production date is 09.94 and the car has 182xxx miles. Lately, it's been having a pulsating (tap tap tap) noise at idle that goes away when I rev. I can barely hear it from the inside but it's really annoying, and I don't know whether it's a serious problem or not. I don't know if it's because of the oil grade I am using (I switched to Mobil 1 0W40 oil last time I did an oil change ) or whether there is a vacuum leak somewhere I don't know. Any suggestions on troubleshooting?

p/s I'll probably record the video and upload it later...
Please help!
Here is the video btw:

http://www.youtube.com/watch?v=rQHMqT_O1kA

[russiankid]

Wouldn't be surprised if its your VANOS.

[ShapeShifter]

sounds like the litters are not holding pressure with the thinner oil.

[russiankid]

I have this same issue and it was present with thicker oil. I think its the VANOS.

[SpeedsterBek]

I have this same issue and it was present with thicker oil. I think its the VANOS.

So should I switch to different oil? I never had any problems with BMW 5W30 or 15W40 oil. Also, if it's VANOS, how much $$ it's gonna cost to fix it?

[russiankid]

So should I switch to different oil? I never had any problems with BMW 5W30 or 15W40 oil. Also, if it's VANOS, how much $$ it's gonna cost to fix it?
Well the fix isn't cheap. I would venture a guess around $200. However, if you do not notice any problems in performance I wouldn't worry about it. You could try switching oil. I have Castrol GTX 10w30 in mine and it purs like a kitten with the slight tap noise as you mentioned.


Now that you made me think of it you need to listen carefully. I just remembered mine comes from the torque converter. From past experience, that isn't the first time I've heard them do that.

Edit: You have a manual....oh I envy you.

[SpeedsterBek]

Well the fix isn't cheap. I would venture a guess around $200. However, if you do not notice any problems in performance I wouldn't worry about it. You could try switching oil. I have Castrol GTX 10w30 in mine and it purs like a kitten with the slight tap noise as you mentioned.


Now that you made me think of it you need to listen carefully. I just remembered mine comes from the torque converter. From past experience, that isn't the first time I've heard them do that.

Edit: You have a manual....oh I envy you.

Haha yeah I love the manual, but there are days when I with I had M3 with a DCT :D.(my dream car!) At least it keeps people from borrowing my car since they can't drive a stick!
Anyways I uploaded the video. I'll be switching to BMW synthetic 5W30 on the next oil change. For some reason, my car didn't like the mobil 1 synth. 0W40 oil. It's not as smooth as it's used to be, and it idles like crap. So I'll see how it goes on the next oil change.

[russiankid]

That sounds like an exhaust leak or a loose spark plug.

[CleanE34]

yeah. not to worry you or anything. but my car used to do this noise, well atleast before the engine went. but on another note. does the noise go away when you rev the motor? if i remember, i think that noise was the intake.

[russiankid]

From the video I doubt its his intake. It doesn't sound like the bottom end.

[SpeedsterBek]

Should I also check for a vacuum leak?

[russiankid]

Wouldn't hurt to do so.

[attack eagle]

that sounds like lifters or an exhaust leak.