As a BMW enthusiast, you might be familiar with the concept of “wear items” — car parts such as tires, brake pads and clutch disks. Because these types of components are designed to wear down, you expect to replace them over the course of your vehicle’s life.
Some components that need replacing are in the gray area, though. Your Bimmer’s springs are one of them. Depending on how long you own the car, you may never observe any noticeable difference in spring performance, but if you’ve come into possession of a car later in its life, your springs might well be due for a refresh.
Why Springs Matter
Your BMW uses coil springs to control lateral body movement. This is typical on driver-oriented cars like your Bimmer, and is generally held to be a more responsive design than the long leaf-type springs used on pickup trucks and even some modern cars, although they may last a bit longer.
Your car’s springs are at work all the time, even when your car is parked. They have to work harder when your car is on the road, and harder still during spirited driving or if you’ve got a very full car.
While your car’s springs are made of highly resilient steel, it is possible for them to fail outright. Typically, if this happens, it’s related to another problem in your car’s suspension, or due to corrosion from the setting you’re driving in. If you can avoid rust and drive the car regularly, but not abusively, your factory springs will continue to provide a responsive driving experience for a long time.
Identifying a Worn-Out Spring
Over time, your car’s springs may start to sag a little bit. If you’re very fastidious about your BMW, you’ll want to replace them right away, but there’s no danger in driving with slightly worn springs. However, your car will exhibit more body roll than it should, and you won’t get the same performance driving experience BMW built the car to deliver.
If a spring fails entirely, you’ll want to replace it right away. In this scenario, the symptoms will be much more pronounced on the corner of the car where the failure has occurred. You may even hear the suspension bottom out during hard cornering.
When Is It Best to Replace Springs?
For owners with earlier-model cars who want to breathe some life back into their suspension, a good rule is to swap your springs out at around 140,000 miles. Depending on whom you ask, you’ll get answers that range all the way up to 250k. It’s more a subjective measure at that point. How sloppy can you tolerate your BMW handling?
Most BMW owners don’t have much patience for this type of thing, and will make the decision to install fresh springs rather than trade in the taut, grippy feeling their car should have. In higher-mileage applications, it might be a good idea to check on the condition of your struts or shock absorbers as well. These components tend to have similar service lives.
With a fresh set of springs installed, you’ll be back on the road enjoying your BMW the way it was meant to be driven.
Who wrote this CRAP? Springs measured by MILES? What? The more the whee rolls the more the spring wears out? So no weight sits on the springs when the car doesn’t move?
Springs don’t “Wear out” or “Sag” That just doesn’t happen. Crappy steel may fatigue over TIME and come out with reduced strength when loaded with weight. But you’ll need really crappy car to do that. If the article was true, we’d have 1970’s GM cars sitting all the way to the ground!
What wears out is your suspension DAMPER aka Shock absorber. They do not absorb any shock, they actually make the SHOCK you might feel if they resist the spring movement too much in order to control the spring and reduce bouncing.
When the seals on the damper rods wear out over time, the fluid and gas leak out, nothing really controls your springs. The reduced resistance from damper makes the weight all on the springs and lower the car a bit as well.
Without dampers, the car will keep bouncing anytime the springs are worked over bumps. Handling will become very poor and dangerous. The car will keep slamming into the ends of the suspension travel, making poor ride quality.
If your car drives like crap, replace the dampers. Most of them go out after 60k miles on normal roads.