Regular Oil Changes are Key to Maintaining BMW Performance In Plano Tx.

Regular oil changes are an important part of vehicle maintenance, but not everyone is clear about why or what counts as regular. We’re going to discuss that here, and we’ll share a cautionary tale of what happens if you delay an oil change too long. (Spoiler alert: it can mean an expensive yet avoidable BMW repair.)

More Than Lubrication

Oil minimizes wear and friction between engine components. It also pulls heat away from the engine, helping prevent it from overheating. In engines like BMW’s four cylinder 2.0 liter N20 it has a third function: it’s used to activate the variable valve timing system BMW calls VANOS.

VANOS works by pumping oil through a small orifice to move a gear that changes engine timing. This is one of the ways in which BMW gets 240 hp from that engine. However, if the oil isn’t clean the system doesn’t work so well, and may stop working completely.

Three Ways Oil Gets Dirty

  1. It collects microscopic particles as metal parts make contact at start-up.
  2. It gets diluted by combustion gases and unburnt fuel squeezing past the piston rings.
  3. High temperatures and pressures break down the molecules that give it lubricity.

What About Synthetic Oil?

Virtually all modern engines use synthetic oil. These are cooked up in a lab rather than being directly extracted from the crude that comes out of the ground. They last longer than the old oils but then modern engines work them harder, so yes, they still wear out.

What Happens When an Oil Change is Delayed?

BMW recommends the oil in their N20 engine be changed at 10 – 15,000 miles. We believe that’s too long, and here’s why:

  • Neglected engine oil turns into a sludge that blocks oil passageways and reduces flow. That degrades lubrication, cooling and the VANOS system.
  • Long before oil turns to sludge it loses effectiveness as a lubricant. That increases friction and wear.

A Cautionary BMW Repair Tale

A BMW 328 with the N20 engine wouldn’t start. Having verified that the camshafts were turning, (thus proving the timing chain was okay,) our Technician removed the valve cover. Here he found very dirty oil and promptly diagnosed a VANOS problem. Putting it simply, dirty oil had put the engine timing way out of whack.

This was a somewhat costly BMW repair, but more work was needed. Before we could change the oil we had to flush the engine to remove all the sludge. That was more time and money.

Oil Changes and Maintaining the Performance of Your BMW

We strongly advise having the oil changed every 5 – 7,000 miles. Why so often? Two reasons:

  1. It’s much less expensive than a VANOS repair and engine flush.
  2. It helps ensure the VANOS system functions smoothly, which contributes significantly to the power and torque the engine delivers

As to why we suggest a range, it depends on the type of driving you do. In a car that spends its life leisurely cruising the highways, oil doesn’t get worked too hard and so lasts longer. If however your driving is mostly short trips in urban environments, and especially if you enjoy using the performance your BMW has to offer, the oil will deteriorate faster.

Bottom Line

Oil changes are essential and it’s better to do them more frequently rather than less. If you need an oil change or have questions or concerns about vehicle maintenance, bring your BMW to EurAuto Shop in Plano TX. and we’ll take care of you. Call (214) 552-4194 or Make an Appointment.