Noise

From Celica GT-Four / Alltrac - ST165 ST185 and ST205

Your first task is to isolate roughly where the noise is coming from, so we can narrow down the area, and what it sounds like:

Knocks

• Knocks over bumps, most pronounced when hitting bumps with one wheel or diagonally with both would tend to indicate Anti-Roll Bar bushes or droplinks. These can be at the front or the rear.
• Knocking on acceleration or lift-off, from the rear of the car is often the rear diff cushion failing.
• Knocking from the front of an ST205 can be due to the super strut suspension arms wearing - more to follow.
• Knocks on application of the brakes when changing car direction, forward to reverse or vice versa, is often due to the pads shifting in the caliper - double check the retaining pins and springs are correctly aligned and learn to live with it, all cars can do this.
• Knocks while turning, usually at near full-lock and when applying power, are most commonly due to outer CV joints failing, usually this will be accompanied by grease leaking from the affected joint - if the knocking has only just begun you might be able to rescue it with a stretchy boot - leave it for 100 miles and you'll need a new joint.
• Knocks, similar to an outer CV joint knock, in a straight line are often due to inner CVs failing, but these are rare.

Grinding

Grinding indicates moving parts in contact, there are limited places where grinding can occur. Inside the engine or transmission, near the belts or in the driveline. Often grinding is due to play in the wheel bearings allowing the discs to catch the pads oddly - jack the car up and wiggle the wheel in all directions, there should be no play.

• Grinding under braking - check your pads and discs!
• Grinding when cornering - again, bearing play or your car is lowered so far you forgot you needed arch space!

Screech

Screeches come from belts, turbos and brake pad wear indicators mainly.

• Usually belts squeel with rev changes or first thing in the morning.
• Turbos squeel when their bearings have failed and they are boosting, they usually make a shrill whine - do not continue to use the car until this is fixed - shards of compressor can be sucked through your engine.
• Pad wear indicators vibrate on the disc and make a very high pitched squeel, usually when braking.
• Other sources of squeels are failing chargecooler, air conditioning or power steering pumps.

Rattle

• Rattles are normally due to loose heatshields, also loose exhaust manifolds leave their gaskets rattling in the pulses of exhaust gas.

Tapping

• Again, tapping can be attributed to loose exhaust manifolds, gaskets and heat shields.