The content of any article might be expanded / improved in the future - revisit it sometimes.
Seen a mistake? Know something that isn't written? Edit and change this article yourself!
Some images in the article (if present) can be enlarged by clicking on them.

This article is just an embryo. It is an idea for someone to "pick up" onto and to expand the article further.

Introduction

If your M13A engine develops strange operating noises (like whirring, higher picthed buzzing, squealing, etc.), this article might help in the diagnosis.

The cause is usually one of these (from the most common to least common):

• One of two drive belts (lost tension or jut worn out);
• Some belt pulleys or tensioners;
• Alternator bearings;
• Radiator fan;
• Water pump;

Diagnosis

There are several method of diagnosis. They are listed from the quickest / simplest to the most labor intensive or complicated ones.

"Stethoscope method":

• Take a long wooden or metal rod (for example a long screwdriver or a long wrench) and put it against various engine parts and accessory devices.
  • Be careful not to "slide" the rod around!
• Then put your ear up to the rod and try to locate on which part the strange sound is pronounced the most.

Temporary belt softening method:

• Put a little chalk dust onto a belt.
  • If the noise vanishes, the belt is probably worn out.
• You could also try this with WD40, but this is recommended only if you intend to replace the belt afterwards anyway.
  • Reason: WD40 might spoil belt's friction properties for a long time.

Temporary bearing lubrication method:

• Spray wd40 into each pulley's or other bearings whilst the noise is being generated.
  • Use the straw on the WD40 can to avoid WD40 getting on the belts.
    • If the noise changes when some bearing gets sprayed with WD40, you have found your main suspect.

Coarse elimination method:

• Take off the belt for the power steering, by slackening the bolts through the adjuster.
• Then turn on the engine and see if it is still noisy.
  • If the noise is gone, it's either that belt or the power steering tensioner.
  • If the noise is still present, then it's most likely something of the remaining parts from the above list.

Total elimination method:

• Take both driving belts off.
  • Note: You should not turn the engine on while both belts are off, at least not for more than a couple of seconds.
• Then spin the alternator and water pump by hand and wiggle the pulleys to feel for play or any noise or coarse turning.
  • If one is tight or has too much movement in the bearing, it becomes the main suspect.
    • The power steering pump pulley will be hard to turn, so you'll only be able to feel for excessive movement.

---

Page last edited on 27/04/2018 by user Bosanek