Back in the old days, instead of an engine computer telling your spark plugs when to fire, it was the distributor. These were phased out over the 1990’s to 2000’s period. If you have a car that still uses a distributor then it must be a classic - good for you! 

What is a distributor rotor and cap? 

When your camshaft rotates, it spins a gear located at the front or back of the engine. This gear then spins a shaft that spins a rotor that is covered by a ‘cap’. As the rotor spins it sends a magnetic charge to points inside the cap, these points then transfer the charge to the HT leads which take the charge to the spark plugs and fire them at the exact right time. 

Why do you need a distributor rotor and cap?

It’s what signals the ignition coil to send the charge to the spark plug. This makes your engine work as it should. If it starts to fail then that can lead to issues such as misfiring, engine damage and the car not running at all.

How to tell if you need a new distributor

If you find that the car is backfiring, misfiring or not firing at all, then it could be the fault of the distributor. If you notice a rough idle or that it keeps stalling out, that’s also a key indicator. Any moisture can ruin a distributor and these symptoms imply the need for a new one.

What’s involved in getting a distributor replaced?

The mechanic will lift the bonnet and locate the distributor by following the ignition leads. The leads will be disconnected from the distributor and the distributor cap will be unclipped and removed. The distributor rotor will be unbolted and the assembly removed. The new distributor will be installed in its place and the cap fitted. The leads will be refitted and the engine run and timed. 

How much does a distributor rotor and cap cost near Hawera?

It depends on the style and price of the new distributor. Generally starting around $325 and easily climbing over $600

How often do I need a distributor rotor and cap replaced?

Sometimes they’ll last the lifetime of the car. Most of the time you won’t have to worry about them till after 150,000km

Is a broken distributor rotor and cap unsafe?

It will generally mean that your car won’t run or will run very poorly. It can also lead to engine damage which can set you back far more than a new distributor.

You can find a mechanic near Hawera with My Auto Shop