In this brief article, we are going to discuss the suspension issues that occur in the BMW E46, what causes these failures and some troubleshooting tips.
The Top 5 Most Common problems with BMW E46 Suspension are:
- ‘Judder’ while hard Cornering
- Rear Squeaking Noise
- Steering wheel shake at low RPM
- Knock Sound while Steering
- Front ‘Clunk’ Noise
BMW E46 Suspension
The BMW E46 is the fourth generation of the BMW 3 Series range manufactured between 1998 and 2005. The E46 M3 performance-oriented model was introduced in the year 2000 in a coupé body style.
The E46 front suspension is carried over from the E30 3-series models. It is a MacPherson Strut suspension with an Anti-Roll Bar.
The rear changed from a simple trailing arm of the previous E30 to the more advanced “Z-link” rear suspension. This arrangement has a large semi-trailing arm, an upper link and a lower link per side.
Troubleshooting problems with BMW E46 Suspension
‘Judder’ while hard Cornering
- The problem appears while during slightly fast cornering
- RH cornering feels OK even if speed is slightly increased
- While LH cornering, HUGE ‘judder’ and the traction light comes on
- It feels as if the rear inside wheel is ‘flapping about’
Troubleshooting ‘Judder’ Problem
- Judder problems usually point to a problem in lateral grip. Now this could be either the tires or the Rear Shocks.
- It seems that the inside wheel was not planted enough on the tarmac to get lateral grip
- If the Tire is ruled out then the only remaining Root Cause is the Rear Shock absorber. Weak/Leaking Shock Absorbers can cause lateral grip problems.
- Check the shocks for Ruptured mounts and oil leakage stains on the shock tube
- Even if there are no oil stains, the shock could have simply worn out over the miles. Typically the shocks would last around 40K miles depending on usage. It is recommended to replace at 50K miles, when you would most likely see deterioration in performance
- While replacing the shock, make sure to replace the rubber mounts and bump stops as well.
Rear Squeaking Noise
- The Rear squeaking happens when going slowly and climbing a carpark ramp
- Otherwise no noise issue while going over bumps
Troubleshooting Rear Squeaking Noise
- In order to identify where exactly the squeak is coming from, you can simulate the rear suspension movement and closely observe the squeak closely
- For this, lift your rear body and place it on Jack-stands
- Now use a hydraulic jack to lift and lower the rear wheel hub to simulate suspension movement
- Move the rear wheel carrier up and down a few times and listen closely for the source of the squeak noise.
- If needed, you can use a long shaft Screwdriver and place the handle at your ear while the tip is at various suspension mounting points.
- Lower Control arms are known to squeak from past experience
- If the bushing is still intact and in working condition, you can try a “Quick-Fix” solution to eliminate the noise problem
- Use a Pointed tool to poke holes into the exposed Rubber Portion of the Bush
- Spray WD 40 into the new bushing holes using a nozzle
- Once again, using the Hydraulic Jack, move the rear wheel carrier up and down in order to let the lubricant spread throughout the joint.
- Lower the vehicle and see if the problem has been eliminated in normal driving
Steering wheel shake at low RPM
- The steering wheel starts to shake at low RPM / engine loads.
- Tire Balancing verified to be OK
Troubleshooting Steering wheel shake at low RPM
- The first item to suspect would be the Control Arm bushings
- From experience, these do wear out and cause minor stability issues
- To avoid risk, BMW front control arms are frequently replaced when the bushings wear out, as they are press-fit.
- If, for some reason, during the press-fit process, the control arms get bent or distorted, it could result in a variety of problems related to the steering and front suspension.
Knock Sound while Steering
- When the car is at standstill or very slow speed, ‘Knocking’ or ‘Creaking’ sound every time the steering wheel is turned
- More noise when locking the steering
Troubleshooting Knock Sound while Steering
- Jack the vehicle and remove both front tires
- Have someone move the steering wheel back and forth while you listen carefully to the sounds that the front suspension is making
- For MacPherson type of Front suspension, Strut Top mounts are known to become noisy when they fail.
- Damaged Top mounts do not allow the strut to rotate when turning the steering wheel. This creates the ‘Knock’ or ‘Creak’ sound
Front ‘Clunk’ Noise
- Almost a continuous noise during normal driving
- The Noise gets really worse on a rough patch
Troubleshooting Front ‘Clunk’ Noise
- Front Clunk noises on a Rough patch is most indicative of Anti-Roll bar (ARB) linkage related issue
- Apart from cornering, the ARB’s work a lot while driving on a rough road since the wheels articulate in a roll motion
- Inspect the ARB assembly and check all linkages
- The first linkage to fail within the ARB assembly is the Drop Links
- The Rubber boot covering the ball-joint usually ruptures due to ageing and the ball-joint inside loses lubrication and eventually rusts or seizes
In this brief article we have discussed the suspension issues that occur in the BMW E46, what causes these failures and some troubleshooting tips.