How Do You Know if You Need a New Distributor Cap on Your Car

Distributor caps and rotors: Your FAQs answered

Every time you go into your car and hitting the ignition, a complex chain of events unfolds nether the bonnet. In a matter of seconds, the ignition system generates a colossal corporeality of electrical free energy, which produces a spark and ignites the fuel and air in the combustion chamber. The engine then roars into activeness, and y'all're set up to become.

The distributor — including the rotor arm and a cap which covers it — is one of the many parts in this organization. So, naturally, y'all'll experience all kinds of problems when something is wrong with it — in fact, your motorcar may not start at all. To assist you get dorsum on the road every bit quickly as possible, we've put together this handy guide to distributor caps and rotors, include a step-by-pace guide on how to replace them. Nosotros'll embrace:

• What does a distributor do?
• Signs of a moisture or bad benefactor
• When to supercede a distributor
• How to supersede a distributor

What does a distributor exercise?

The purpose of the distributor is to direct high-tension voltage (besides known as the secondary current) from the ignition coil to the spark plugs at exactly the right fourth dimension and in exactly the right lodge to create a spark. This then ignites the engine, firing upward the cylinders and powering the car.

The benefactor is comprised of a number of dissimilar components, the almost important of which are the rotor arm, ignition points, and a benefactor cap with output contacts that connect to the spark plug cables. There are multiple contact points arranged in a ring around the rotor arm, and each connects to a dissimilar spark plug. The benefactor rotor arm is connected to the ignition coil by a cable and a leap-loaded carbon brush. This sealed unit is mounted on the distributor shaft, which is continued to — and driven by — the engine camshaft.

When the engine turns the camshaft, the distributor shaft turns every bit well, spinning the rotor arm inside the distributor. As it turns, the metallic role of the rotor arm passes very close to the output contacts. A very high voltage (the secondary current) is and then delivered from the ignition curl into the distributor rotor arm. Because the voltage is very loftier, information technology is strong enough to jump across the pocket-size gap between the spinning rotor arm and the output contacts, which and so direct the charge to the advisable spark plugs. This allows the benefactor to deliver the high-voltage current to the right spark plugs at the right fourth dimension, which keeps the engine cylinders firing in the correct club.

These days, car manufacturers are moving away from traditional benefactor ignition systems, and nearly mod cars are now fitted with electronically controlled systems instead. However, many vehicles produced before the mid-noughties nonetheless use distributor ignition systems.

Signs of a wet or bad distributor

Simply like whatsoever other serviceable part, the distributor can wear downwardly over time, and it tin besides be susceptible to water damage if any moisture seeps within the cap. If there'south a problem, you may notice the post-obit signs of a wet or bad distributor:

The car doesn't first

If the engine won't turn over, the culprit could exist a faulty distributor. When the distributor cap is loose or damaged, and then the rotor arm may not be able to generate the spark needed to direct voltage to the spark plugs. Without this, the spark plugs tin't fire and ignite the engine.

If your engine has died suddenly, then retrieve that in that location may be any number of other causes for this: the problem isn't necessarily with the distributor. If you can't find whatsoever faults with the distributor, and then accept a look at our car-starting problems guide to figure out what may exist causing the issue.

The engine misfires

If any part of the distributor is faulty or damaged, then the ignition timing will be affected, which tin cause the engine to misfire. So, you'll want to check the distributor for signs of water damage or vesture and tear — nosotros've outlined what to check for below.

The check engine light comes on

While at that place may be many reasons for the Cheque Engine lite to come up on, one of the possible causes could be a bad distributor. If you own a fault code scanner, y'all can apply this to piece of work out whether or not the distributor is causing this.

You hear strange noises coming from the engine bay

When the distributor rotor and cap are malfunctioning or muddy, the cylinders volition try to burn down only fail to ignite. This means a surplus of air starts to circulate through the engine, resulting in a loud squealing or whistling noise. The engine may also splutter loudly or make tapping and clicking noises.

How can I tell if the benefactor is bad?

If y'all suspect that the distributor has developed a fault, you'll want to get under the bonnet and bank check to see if it is damaged, worn, or loose. Visually inspect the cap and rotor carefully: the internal and external surfaces should be make clean and complimentary from corrosion or rust. The rotor arm in particular needs to be in very good condition, every bit the spark may not be able to pass from one last to some other if it is dirty or damaged. So, check it carefully for whatever build-up of carbon or pitting.

You should also check that there are no loose parts and that the cap and all cables are tightly secured. If you observe a problem, you will need to replace the affected parts or mayhap the unabridged distributor.

When to supplant a distributor cap

As a rule of thumb, the distributor should be replaced every l,000 miles or 5 years, depending on which milestone you reach first. Still, service intervals for the distributor cap and other distributor parts tin can vary, then bank check the owner's manual or Haynes manual to detect out exactly when to replace them. You lot will likewise demand to replace your benefactor cap earlier than the recommend interval if information technology develops a fault or becomes damaged by water, as this could forestall your car from starting at all.

If your distributor is overdue a replacement, don't put this job off. The benefactor rotor arm is exposed to loftier voltages every time the engine runs, and if they aren't maintained or replaced regularly, it can gradually reduce the engine efficiency of your vehicle. Then, be sure to service your distributor at the recommended intervals and supercede it when necessary.

How to supervene upon a distributor

Replacing a distributor cap is an intermediate task that most apprentice mechanics with a bit of experience and a solid understanding of the ignition system should be able to carry out. However, the complication of the job tin can vary depending on the brand and model of automobile. And then, we would always recommend checking your car possessor's guidebook or reading the relevant section in your Haynes manual. If the job is beyond what you feel comfortable with, be certain to consult a professional mechanic.

Before y'all begin, you volition need the following tools and parts:

• A replacement benefactor. This should include the rotor and distributor cap. These must be the correct blazon for your vehicle — check your handbook for more information or use our product-finding tool to view the right parts for your auto.
• Assorted hand tools including a wrench, screwdriverset, and socket set.
• A marking pen for mark the right position of the rotor and the guild of the spark plug cables. Make certain this is a bright color that will clearly stand up out against dark materials and won't rub off.
• The timing specifications for your vehicle. In social club to correctly install the replacement distributor, you'll need to set the timing of the engine once the new office is installed. All vehicles take their own unique timing specifications, so be sure to discover these before you lot begin. They can ordinarily be found on a sticker nether the bonnet or in the engine compartment. They may also be detailed in the owner's manual. This information is crucial, so if you can't discover the specification, don't attempt to carry out this job yourself: take your auto to a professional.

Now, permit's take expect at how to supplant a distributor step by footstep:

1. Get set up: Park your car on an even surface, appoint the handbrake, and switch off the engine. Gather everything you'll need for the job (listed above). Ground the battery by removing the negative battery cable.
2. Detect the distributor: Open the bonnet and locate the distributor. In most cars, information technology'south positioned direct above or to one side of the engine, but cheque the Haynes transmission or owner's guide if you tin can't come across it. The distributor volition exist cylindrical in shape and should have a plastic cap with several thick cables attached to it — these are attached to the spark plugs. There'south also some other wire which attaches to the ignition coil.
3. Remove the benefactor cap: The cap will normally be held on using hinged clips or bolts or a combination of both. Pop the clips off by hand or with a flat-head screwdriver and unscrew whatsoever bolts with a socket wrench or screwdriver. Once all fastenings are removed, pull the cap away from the body of the distributor.
4. Marker the spark plug cables and output contacts: Take your marker pen and number all of the spark plug cables and output contacts so y'all tin can reconnect the cables with the matching outputs on the new cap. This will ensure you don't accidentally interfere with the firing order.
5. Marker the engine mounting point: To get in easier to fit the new distributor correctly, marking the signal on the exterior of the distributor housing where the distributor is mounted to the engine. This will make it easier to accurately line up the new housing the with engine mounting signal. The replacement rotor may accept an indentation on it to betoken where the mount should line up with, merely it never hurts to exist too conscientious!
6. Mark the rotor: Mark the distributor housing to betoken the position of the rotor. It's important that this is equally accurate as you can brand it, as the machine won't showtime if the new rotor isn't in exactly the aforementioned position equally the old 1.
7. Remove the erstwhile distributor: Unscrew whatsoever bolts or screws that are holding the distributor in place and carefully elevator information technology away from the benefactor shaft.
8. Mark the new distributor: Have the replacement benefactor and make the same marks on the housing and rotor that you made on your old distributor, taking care to put them in exactly the same places. This will ensure the role is in the same position equally the old version.
9. Line upward the rotor and re-install the replacement: Re-install the replacement distributor. The position of the new rotor must friction match the position of the sometime one or the car won't start. So, brand sure the new rotor is lined upwards with the marker yous made earlier. Exist careful not to accidentally nudge the rotor out of alignment when placing information technology onto the distributor shaft.
10. Secure the distributor using the mark on the engine mount: Secure the new distributor in place. To make sure it's in exactly the right position, make sure that the mark on the distributor housing lines up with the marking you lot made on the engine mounting point. When it's in right position, supervene upon whatsoever bolts or screws. Don't fully tighten them, still — yous need to be able to adjust the position very slightly afterwards when checking the ignition timing.
11. Replace all the cables: Replace each cable using the markings you made before as a reference point to brand sure that each one corresponds to the original connection on the one-time rotor.
12. Check your connections are sound: Check the connections between the cables and the distributor are sound. Reconnect the negative battery terminal.
13. Effort to get-go the engine: Try to switch on the engine. If it starts on the first endeavor, let it idle for a minute or two to warm up the engine. If the engine won't quite plow over, you'll need to re-conform the rotor arm by turning information technology very slightly and try again.
14. Check the ignition timing: Once y'all've successfully started the engine and left it to idle, switch it off again. Place a timing lite device on the first spark plug and and then re-commencement the engine. Post-obit the timing instructions for your vehicle, adjust the timing by rotating the distributor housing by very small amounts. When the timing is exactly right, you can finish tightening the bolts or screws that concur the benefactor housing in place and lower bonnet.

Well washed — you've now successfully replaced a distributor! If information technology's been a while since you concluding serviced your ignition, you could besides have this opportunity to clean and alter the spark plugs .

Here at GSF Car Parts, nosotros take all the parts and tools you need to go your ignition system back up and running, including ignition cables, rotor artillery , ignition points , ignition condensers , and benefactor caps for all makes and models of car, all with free Britain delivery when you spend over £25. Or, if y'all need to go your distributor fixed in a bustle, take advantage of our speedy Click and Collect service, which allows you to pick up your new parts as rapidly every bit an hour subsequently ordering. While y'all're here, be certain to check out our auto advice centre to discover helpful how-to guides on all things automotive.

How Do You Know if You Need a New Distributor Cap on Your Car

Source: https://www.gsfcarparts.com/knowledge-hub/distributor-cap-and-rotor-guide