The MGF Register Forums

In my ongoing quest to learn about how our cars tick I have come across some interesting opinions about manual cars.

In the US, many manual cars now come with a 'clutch switch'; the idea being that the starter motor will not go unless the clutch pedal is depressed,
ensuring a child cannot turn the key and start the car. One of my sons used a driving school car with a switch like this.

I am told with the clutch depressed, the pressure plate exerts force onto the crankshaft thrust bearings ( also called thrust washers )

This is fine with a running engine with normal oil pressure, BUT in the moment when you crank the starter motor there is no oil pressure,
and all the bearings are going to be dry, particularly when cold after a night ( or weeks ) on the garage. I am reliably told that your main and big end bearings can handle this, and anyway you have no other choice except to walk; but car makers are supposedly finding faster wear in the thrust bearings of cars with clutch switches.

Ssssssoooooooo...... do not crank you starter motor with the clutch pedal depressed. Always start with neutral gear engaged and your foot OFF the clutch pedal.

As with all things on here, this is just an opinion, but it can't seem to do any harm starting our cars this way.

I remember a friend having a Japanese car (can't remember what) on which you couldn't start the engine unless the clutch was depressed. Another way to time limit a car so that repairs are necessary?

Not just the US, Canada as well. Our Toyota is like that, what a pain in the butt.

Always start mine with the clutch in ,all my cars from the when I started driving .It prevented running down the chap with the red flag if the gears were engaged . My bikes have switches on the clutch as well.

Most new cars have to have the clutch depressed to start our last 2 Skodas did.

My daily alfa 159 requires either the clutch or the brake to be depressed, I normally press the brake.

Advanced driving organisations always advocate depressing the clutch when starting the car. This guards against the car being in gear and reduces the load on the starter motor and battery - which can be useful in cold winters.

I was taught to do this when I learnt to drive and have been doing so for the last 50-odd years. It certainly saved me on at least one occasion when the 'stirring the pudding' gear lever/gearbox in a (it was either an Allegro or Metro) suggested it was in neutral but was actually in gear when starting.

Similar to others above, it's a requirement of my current Audi.

Far simpler to fit a switch to the gearbox so that the car won't start unless it's in Neutral.

I think someone is trying to solve a problem that doesn't need solving. Having been an Advanced Police Driving Instructor we ALWAYS taught students to start the car with the clutch depressed. This is because we encourage people to leave the car in gear when parked, to stop it running away - there are many cases of that happening particularly cars with handbrakes that work on rear disc rear brakes, and also to avoid smashing the front or rear of the car into a wall or another vehicle when operating the starter (believe me it happens, often).

In all my years driving and dismantling engines I have never come across this "worn out thrust bearing" scenario, except when allied to other wear problems in the engine.

One benefit is if you stall the car when you dip the clutch pedal it starts up well at least our Skodas do

My MG6 cannot be started without depresssing the clutch...

Also i was always taught to hold the clutch down when starting as it reduces wear and load on most componant. ..

I suppose whatever you do, someone will find fault and a better way to do it, i for one will keep depressing the clutch on my ZS, the F and even the RX8 (missed the 6 deliberately, as no choice with that one)

Reckless Rat wrote:I think someone is trying to solve a problem that doesn't need solving.
In all my years driving and dismantling engines I have never come across this "worn out thrust bearing" scenario, except when allied to other wear problems in the engine.

As far as I'm aware, thrust bearings don't normally get a pressurised oil supply, depending on the plentiful supply of extruded oil from nearby bearings. On a cold start, no bearing gets a full pressure oil supply anyway

A benefit of depressing the clutch on a cold start is taking the load of the drag of the gearbox bearings/ oil off the starter motor, sometimes essential to spin the engine fast enough to fire up.