A Beginner’s Guide to the BMW M50 / M52 / S50 / S52 Engine

So, you just bought your first BMW E36…congratulations! The BMW M50 Family of engines is one of our all-time favorites here at 5150, with most of our founders owning an E36 as their first BMW. And we’re not alone; the E36 is a favorite among countless tuning and performance enthusiasts for builds and track projects. So, we’re breaking down everything you need to know about your new-to-you BMW to help restore it to proper functioning before any high performance upgrades:

First, the Good

With 50 / 50 weight distribution, the BMW E36 boasts exceptional handling characteristics. For enthusiasts looking for a platform well-suited for track days, drifting, or autocross, the E36 is an excellent choice. 

Rear Wheel Drive means the BMW E36 provides excellent driving dynamics and a natural, responsive feel. Combined with its lightweight and compact body, the E36 is both nimble and solid.

A widely-produced BMW, the E36 has a huge aftermarket of new and used components for enthusiasts to choose from, as well as a massive stash of community knowledge and know-how. For nearly any modification, repair, or upgrade you need to perform, there is another enthusiast who can offer you insight on how to best get it done. 

The M50-family, including the M52, S50, and S52 engines, are widely celebrated for their durability and tuning potential. This hearty engine is a great platform for power-adders, such as turbochargers or superchargers. 

Next, what to look out for

Cooling System Failures

You’ve probably already heard other enthusiasts discussing the E36’s faulty cooling system and for good reason; it’s one of the most common systems to fail on these vehicles. Let’s break down some of the most common weak-points of this system:

Our recommendation: Replace these components with their aftermarket alternatives right away for peace of mind and to prevent the much more significant damage an overheating engine would cause, especially for those who anticipate traveling significant distances. If you can only change one, upgrade to a Stewart Water Pump, which features metal impeller blades. 

Suspension and Steering Component Wear

It goes without saying that, aging well into their 30’s, the bushings and suspension components in your classic BMW are well-worn. The clunking you hear while driving is likely caused by your front control arm bushings and ball joints. Replace these ASAP for a smoother, quieter ride and improved handling.

In the back, the RTAB [Rear Trailing Arm Bushings] are also, more likely than not, in desperate need of replacement. Common symptoms of worn bushings are compromised wheel alignment and poor handling stability. 

For all suspension bushing replacements and upgrades, we recommend Powerflex, especially their Handling Pack for E36, which includes both upgraded control arm bushings and upgraded RTAB.

Drivetrain Issues

Clutch and Transmission Issues: as your transmission ages, it will begin to show symptoms of wear and failure. 

Aging automatic transmissions in these vehicles have gained notoriety as ‘sludge boxes,’ known for being less responsive, with a delay in shifting gears. Our recommendation: for those who aren’t ready for a manual swap, flush and replace the old, contaminated fluid in your automatic transmission with high quality transmission fluid and replace worn transmission mounts for better power transfer. If you are still experiencing issues after basic maintenance, it may be time for a rebuild or replacement. 

On manual transmission E36 models, you may find that your aging clutch components are in need of replacement. Some signs that you will need to replace your clutch include difficulty shifting gears, a slipping clutch, spongy clutch pedal, burning clutch smell, etc (in other words, it won’t be fun or easy to drive). 

5150 carries a variety of clutch kits to suit your driving style and needs, available to browse here.