Stationary Gear Bearing Failure

Stationary Gear Bearing Failure is relatively common in the Mazda RX-8 and perhaps the worst, most unavoidable fault that the cars left the factory carrying.

Fortunately though, there are signs that can be identified which might give you a heads up, in advance of complete bearing failure.

‘Stationary Gear Bearing Failure’ Explained

Essentially Stationary Gear Bearing Failure is an issue which develops over time rather than occurring suddenly one day.

It can be caused by a number of factors but the main cause tends to be related to the ultra-low oil pressure that we see in the RX-8 engine at idle. Basically the oil pump does not pump quite enough oil to maintain its pressure at very low RPM’s . The uneven movement of the e-shaft as it turns (due to fluctuations in the pressure) allow it to touch the bearing surfaces through the oil lair which the shaft is supposed to be suspended by. It is possible for a worn bearing to be detected by the on-board diagnostics – but rarely will the engine management system be able to notify you of such a fault until it is far too late.

The tell-tale signs of Stationary Gear Bearing Failure that you should listen out for are:

  • a low droning engine note; this will be apparent at idle and through-out the rev range. If you are experiencing this noise the engine will normally also be very reluctant to rev when in the higher rev band.
  • a sharp and loud clatter when initially starting the engine after it has been parked for a time; this could best be described as a knocking or banging from the engine area and will only likely last a couple of seconds after starting the engine. Some have described the sound as if someone were banging on an old metal dust bin with a baseball bat repeatedly (at high revs).
  • a loud audible clatter at high RPM; this noise can be intermittent as it’s generally related to engine temperature and could be described as similar sounding to static or white noise which you might here from an un-tuned TV or radio.

You could hear any one of these noises alone or experience more than one of them together.

We suggest that if you hear or even suspect that you may have heard any of the above sounds that you bring your car to us promptly for diagnosis. This is by no means over-reacting as the nature of the problem is serious. Our mechanics will be able to tell you right away if your car sounds like it’s suffering from bearing failure based on an audible inspection.

Bearing Failure Repair

Unfortunately the only real fix for Stationary Gear Bearing Failure is a strip down and engine rebuild.

Diagnostics can be carried out to attempt to identify the condition of the remainder of your engine and will tell us whether or not it would be worth simply removing the engine and replacing the bearings alone – rather than disassembling the main block of the engine and rebuilding the entire engine unit.

In most cases any money spent carrying out this lesser-task would almost certainly be better spent being put towards a full rebuild.

If you have any questions or would like to talk to someone about your car and/or bearing failure, contact us.