What happens when engine timing is off?

Timing belt on pulleys

When the engine timing is off

Timing is everything, especially when it comes to how well your car is running. When the engine timing isn’t right on car, it can affect how it runs, drives, the gas mileage, and more. This is especially true for a German made car like the BMW. 

There are many components and parts to a car engine, many of them are rapidly moving to keep the car running. Each of these parts are important to the engine timing, such as the camshaft, crankshaft, engine timing belt, engine valves, pistons, pulleys, and rod being the main ones that keep your BMW running as it should.  

 The engine valves correspond with the pistons as they move up and down. As the crankshaft spin, the connecting rods pull and push. Each of these things have to work in perfect coordination for the engine timing to be in sync and run correctly and smoothly. There are two types of engine timing: cam timing and ignition timing. The pistons and valves are regulated by the cam timing, which is controlled by the engine timing belt.

 What can happen if the timing is off? 

The engine of your BMW can be damaged by timing that is off. There are “interference engines,” like those in BMWs, and the consequences of bad timing can be notably bad. Because the engine pistons and valves fill the same space in the engine cylinder, but with different timing, the intervals between the timing of the two occupying that space is less than one second, aka, the engine timing. 

So, if that part of the engine timing is off, the two can hit each other, which would likely result in the engine needing to be rebuilt if you’re lucky. The other scenario, the more expensive result would be engine need replacing. If the engine timing of the cam is off, your car will either be running rough or not at all. If the ignition timing is the problem, it isn’t as easy to notice because it has four cycles:

  • Intake valve sucks in air while fuel is delivered by the injectors.
  • The fuel mixture is reduced.
  • The spark plug and fuel mixture combust and push the piston down.
  • The exhaust valve opens, letting the exhaust out.

If the spark isn’t happening in perfect time, the car will idle rough or choppy, it could lose power, and the engine quits running. 

What are the symptoms of a bad timing?

The timing belt is commonly found in located in front of smaller displacement engines, under a cover specific to the timing belt. It rotates the cam and crankshaft to ensure that each cylinder fires in perfect timing. If the timing belt is key in the engine timing because if it isn’t right, the car doesn’t run.

However, there is not a timing belt in all engines have a timing belt. Larger engines with a larger bore and stroke are equipped with a timing chain. According to professional mechanics, timing chains have a longer lifespan than a timing belt. There are some common symptoms that are indicators a timing belt has reached its life expectancy: 

  1. Engine Has A Ticking Noise: A series of pulleys attach the engine timing belt the engine’s camshaft and crank, allowing the crankshaft to power the connecting rods that are attached to pistons. The cylinder head valves, and rocker arm assembly are operated by the camshaft and sends fuel through the combustion chamber where the burnt gases are expelled through the exhaust manifold. When the timing belt begins to wear out, a ticking sound will sometimes start inside the motor. That ticking sound is either low oil pressure or the not the right lubrication n the engine. Once you hear this ticking noise, take your car to the mechanic promptly. 
  2. Engine Won’t Start: If the engine timing belt has broken, it won’t be able to start. You may hear it “engage” as it is trying to start as you turn the key, but because the engine timing belt is what operates the camshaft and crank that turns the engine, it isn’t able to start.  A broken engine timing belt can also cause damage internally. Sometimes an engine timing belt breaks while the engine is on. Typical damage to an engine with the engine timing belt breaks could be to the cylinder head, including the crank bearings, oil pump, push rods, rocker arms, or valves. If the engine timing belt needs to be replaced can be determined by an experienced mechanic. 
  3. Engine Misfiring: A worn out engine timing belt can impact the firing rate of the engine. On occasion, the engine timing belt will slip from the camshaft. This will cause one of the cylinder to open and close sooner than it should, aka misfiring. If the engine timing belt isn’t replaced soon, catastrophic damage can result.
  4. Oil Leak: If there is oil leaking from the front of the engine timing belt cover has bolt and nuts holding it in place, there is a gasket under the cover. The bolts and nuts grow weak with age, the gasket become dried out, or it could be installed incorrectly. With the oil leaking from the engine timing belt cover, your engine timing and overheating could result in the engine timing belt needing replacement.          

What causes ignition timing to be off?

When any changes are made to the engine of a car, the ignition timing is adjusted accordingly. If not, you could experience several problems with your engine with improper ignition timing like knocking, hard to start, increase fuel usage, overheating, and reduced power. 

The ignition timing error is typically caused by damage internally like the pistons or valves inside the engine. A loose or weak engine timing belt that jumps time can cause the ignition timing to be off. 

Will a car start if timing is off?

Ignition timing is the setting of the spark plugs to ignite when there is a compression stroke. When it has been improperly set, the ignition timing will impact how the engine performs and may hinder the car starting. 

timing bel removed from engine block

How do you check engine timing?

An old school mechanic that has worked on older vehicles can adjust engine timing without timing light simply by listening to it. For newer cars, mechanics are required to have come computer technical training and will use a computer to check the car’s engine timing. 

The mechanic may advance or retard the timing as needed. This is done with attention to detail because ignition timing vs engine temperature isn’t set right, it and cause the engine to get too hot and ruin the engine. 

 A BMW is an expensive car because they are built to last forever. Even with that in mind, it is important to keep the car in proper running condition. Any sign of engine timing belt having issues, take your BMW to your trusted BMW mechanic immediately. Call 469-471-6433 today for your engine timing service in Dallas, TX.