Very loud chirping/squeling...any ideas

[mpe50]

Thanks in advance for any replies. Did a quick search, but couldn't find much. Have always found the advice and info here incredibly valuable, so thought I'd ask if anyone might have any insight.

'08 E70 3.0si with 88k miles. Been making a loud chirping/squeling noise for the past few days, but only when letting off the power at lower speeds...under say 40 mph or so. Step on the gas, it goes away. Sometimes at idle, but never on cold start. Seems to show up once the car is warmed up. First time I ever noticed it was after replacing the oil stand gasket. Cleaned up the engine with cleaner and started it up...briefly showed up then disappeared for 2 months til this week.

Brought it in to my Indy, of course it wouldn't do it then. So drove it, parked it for 20. Started it back up, and it showed up again. He said it's odd it only shows up when off the power, but guessed it is the pulleys and belt. Which is logical given it's on original pulleys. But I know there is possibility it could be alternator or water pump. Though pump was replaced 2 yrs ago. Was looking for any ideas on diagnosing I don't want to just throw in a $1000 alternator in the hopes it will fix it when it might have nothing to do with it.

Video of it. Though the sound didn't quite transfer as well. Much louder than in the cabin.

[nezarnuaimat]

I had such noise and found out to be from a loose driven bulley; tightened and all right.
Do this: Call a friend, open hood stare carefully to bulleies & belts while he switches on. You might be able to notice ... Good luck

[mpe50]

I'll check to see if the drive belt pulley is tight. Thanks for that. Definitely sounds like what one would expect a belt/pulley issue to sound like.

Probably completely unrelated, but I also started having VANOS solenoid faults at the same time the noise started.

[LeiZ]

Subscribing...... Same year, same model, same mileage.......

[mpe50]

So I was finally able to replicate it for the shop. He pulled off the belt and spun all the pulleys. Said they all felt fine with no noise or play, as does the water pump. I'm thinking it could possibly be a faulty alternator, but after reading this http://www.e90post.com/forums/showthread.php?t=613808, I'm concerned it might be related to the VANOS code it was throwing (2A82 and 2A89).

[mpe50]

Update. Took it to the dealer. They seemed to think it was related to the VANOS codes it was showing. Wanted $3000+ to tear into it. Figured I may as well try a new solenoid before going down that road, so I picked one up at the parts desk on my way out.

Easy install. The old solenoid was definitely jammed. After 2 days of driving, it seems to have solved my issues. The rough idle, difficulty starting, and noise are all gone thus far. No more codes either. Still confused how it could cause that noise, but happy I didn't agree to tear apart the engine. Hopefully the issue doesn't reappear.

[ard]

Originally Posted by mpe50

Update. Took it to the dealer. They seemed to think it was related to the VANOS codes it was showing. Wanted $3000+ to tear into it. Figured I may as well try a new solenoid before going down that road, so I picked one up at the parts desk on my way out.

Easy install. The old solenoid was definitely jammed. After 2 days of driving, it seems to have solved my issues. The rough idle, difficulty starting, and noise are all gone thus far. No more codes either. Still confused how it could cause that noise, but happy I didn't agree to tear apart the engine. Hopefully the issue doesn't reappear.

I read your first paragrah and my blood pressure shot up...

BMW dealers and VANOS are a sore subject after 10 years with the S62.

The lack of training at the dealership leve- the 'parts replacer' mindset- has cost customers dearly.

Next time simply clean the solenoid with solvent and get it actuating cleanly and smoothly. Long OCIs and fouling causes the solenoids to become sluggish. Running the vanos actuator tests (not just chasing OBD codes) can give you a clearer idea of where the issue is.

Every car that BMW has with VANOS has the same issues: oil fouling, heat, seal shrinkage; sluggish actuation, vanos gradually fails. BMW techs are taught 'replace the whole vanos assembly'. Crazy

And FYI: next time mention CEL and codes.

[mpe50]

I had a feeling they would throw out some crazy number. But I was frustrated with the independent shop not getting very far. Figured maybe the dealer might have more insight. Should have known better. Honestly this forum has been the best diagnostic tool I have found thus far.

I've been pretty good about the oil change intervals, but sounds like it's almost inevitable the VANOS will need servicing at some point. I also made the stupid decision to put off addressing the "service engine soon" message I was getting a week before hand. Glad it appears to be something so simple this time. Now I just have to address the oil dripping from my active sway bar.

[ard]

Easy. New active sway bar. Ive seen one or two posts about replacing this in the last 6 years, here or BF.

[mpe50]

Yeah, I've searched absolutely everywhere I can think of for a DIY on that sway bar. Any idea if it's a pretty simple DIY? Normal sway bar looks to be, but not sure how much the hydraulics complicate things.