Welcome to Tech Talk, where our resident BMW tech Nick Owen answers all your pressing BMW technical questions, frustrations, and issues. Have a question for Nick? Email him at techtalk@roundel.org. Let’s get into it.
Front End Noise
My 2009 335i coupe with M Sport suspension has about 97,000 miles, and I do my best to keep it maintained and running well. The car runs great and is a joy to drive.
The issue that has developed is very puzzling. When taking the car out of the garage and turning the wheels, there is a popping sound like a spring moving. It only happens during turns and when there is a load on the front wheels. If I try to recreate it when on jack stands there is no noise. There is no drifting to one side or the other and the car is very smooth otherwise.
I have looked over the front struts thoroughly and checked the tightness of the bolts. The springs are sitting correctly in the rubber retainers and the spring support piece. There doesn’t seem to be any looseness in the front end and the shop that does my alignments has not mentioned anything. The bump stops are totally worn out but I wouldn’t suspect that this is causing the issue.
My guess is it might be that the strut mounts are binding causing the noise. Struts and mounts and other front suspension hardware were replaced at 45,000 miles.
However, there doesn’t seem to be much play in the suspension when pushing on the front end.
Any insights you might have would be appreciated.
John Calabria
Easley, SC
My 2008 335i does the exact same thing when pulling out of my drive way and hitting the brakes. Left front, every time.
This is usually one of two things:
- Bad ball joint
- Brake pads shifting in caliper
This is common with the E6X model as well. You can try to lubricate the backside of the front brake pads and clean the sliding points to allow the pad to shift in the carrier easier. If you want to check ball joints, you’re going to need a big pair of channel locks in order to compress the ball joints to check for play.
My experience says this is most likely caused by the brake pads.
VANOS Going Bad?
I am the owner of a 1995 325i convertible with an automatic transmission and only about 84,000 miles.
My question: what are the symptoms of the VANOS system failing and needing replacement?
My car idled rough on initial start-up and there is a rattling noise from the top end or cam box area. Replacing the idle control valve seems to have fixed the rough idle at start up. But there is still the rattling sound.
What are your thoughts? I would appreciate your input.
D
Vanos diagnosis on the M50 engine is virtually non-existent. The system is so basic; it cannot self-diagnose. Therefore, you won’t really ever know if it goes bad, except for lack of power on acceleration. Rattling noise from the VANOS area may indicate wear, but not failure. I have worked on dozens of E36s in the past and nearly half of them had a noisy VANOS unit. Even after replacement, there is still some kind of noise there. If you’re inclined to have it replaced, then I would recommend going through drvanos.com. Here you can find everything you will need for VANOS replacement.
