engine vibration

my guess would be engine supports or bushings as what other describe them.

You did not mention the mileage on the car, or if this started suddenly, or if any trouble codes were noticed by the check engine light on, but start with simple and inexpensive stuff first.

It could be a cylinder misfire.

Tune up parts. Change all filters, spark plugs, ect.. Buy new Toyota parts, they work best. Try a dose of injector cleaner as well.

Done 110,000kms. Changed all spark plugs, ignition leads, timing belt, engine mounts. Had injectors cleaned by a mechanic. The vibrations seem to reduce after the car is running hot and when I accelerate. Could this be an oil problem? Perhaps sludge?

I would doubt oil or sludge would be a cause. You did not mention if it does it only in motion, or stopped as well, and under load or no load conditions. If it only does it in motion, look more towards the drive train , such as CV joints, clutch or torque converter, output shaft bearings.

If it does it while stopped as well, look more towards secondary ignition components, you may have a bad plug, coil, or wire. If it has a manual transmission, it may be the clutch.

It may take a bit of investigation to diagnose this one.

Happens both stationary and in motion. Automatic car. Will rechek the spark plugs. The ignition leads are new and are Toyota genuine parts. When the problem occurs, significant vibrations felt @ steering wheel and a labouring sound accompanies the prob from beneath the car chassis. Intermittent.

Try shifting from neutral to reverse or drive. Do you get a big jolt there from the engine? If so check the mounts. Some of these can crack but are hard to see. Just changed out a dog-bone on the passenger side like that.

Don't get the jolts you're talking about. Also engine mounts been changed recently.

Loosen the motor mount bolts, start the engine and raise RPM to 2,000 RPM, shut off the engine, tighten the bolts.