Symptoms of Bad or Failing Timing Gears (Gear To Gear)

The purpose of timing gears is to allow the camshaft and crankshaft to turn the timing chain. The crankshaft turns to move pistons up and down inside the cylinders. The camshaft turns to allow intake and exhaust valves on the cylinders to open and close. These components are important for proper engine timing. As the piston moves downward inside the cylinder, the intake valves open to allow fuel and air into the cylinder. As the piston moves upward inside the exhaust the exhaust valves open to expel exhaust valves from the cylinders. If the intake valves are not opening and closing properly, the correct air/fuel mixture will be unable to enter and remain inside the cylinders. If the exhaust valves are not opening and closing properly, exhaust gases will be trapped inside the cylinder.

If the timing gears are going bad or failing and the timing chains are unable to be turned by the camshaft and crankshaft, valve timing and ignition timing will be off. If valve timing and ignition timing are not accurate, noises from the engine compartment may be noticeable. It is also possible that timing gears that are going bad or failing may cause the engine to run rough, backfire and/or not run at all.

1. Rattling noises from the engine compartment

Rattling noises from the engine compartment may be an indication that the timing gears are going bad or failing. There are several things that can cause noises from the engine compartment. Those attributed to timing gear failure could be caused by the timing gear itself, the timing chain rubbing or hitting something it shouldn’t, or the timing chain guides being broken or worn out. This is a symptom that may be present at the start of the problem or as the problem progresses and should not be ignored. Allowing time to progress without addressing noises heard from the engine compartment could cause damage to other engine components.

2. Engine runs rough or backfires

An engine only runs smoothly when all of its components are in working order. The timing gears are an important component of engine and ignition timing. If the timing gears are going bad or failing, the valves may not open correctly to allow air and fuel into the cylinders or close correctly to release exhaust fumes from the cylinders. When this happens, ignition timing will be off because the spark plugs are not being fired in time, or in order. This will cause a rough running engine condition. It may also cause the engine to backfire. This is a symptom that may be present at the start of the problem or as the problem progresses. It should be addressed as soon as possible to prevent total engine failure.

3. Engine does not run

When a timing gear is going bad or failing, the camshaft and crankshaft may be unable to turn the timing chain. As a result the camshaft will be unable to turn in order to open and close the valves. Also, the crankshaft will be unable to turn in order to move the pistons up and down in the cylinders. It is necessary for all of these components to be in good working condition in order for proper engine timing. If the timing gear is faulty and the camshaft and crankshaft are unable to turn, this may result in the engine not running at all. This is a symptom that may be present at the start of the problem or as the problem progresses.


Next Step

Schedule Vehicle Engine Mechanical Inspection

The most popular service booked by readers of this article is Vehicle Engine Mechanical Inspection. Once the problem has been diagnosed, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Vehicle Engine Mechanical Inspection reviews

Excellent Rating

(169,816)

Rating Summary
159,374
5,600
1,163
825
2,854
159,374
5,600
1,163
825
2,854

Raymond

37 years of experience
382 reviews
Raymond
37 years of experience
Cadillac Brougham V8-5.7L - Vehicle Engine Mechanical - Las Vegas, Nevada
Talent and passion for what you do in any field is critical, Raymond seems to have both. I have dealt with many Mechanics in my day Raymond is one of the best. Thank you sir.

Rusty

23 years of experience
506 reviews
Rusty
23 years of experience
GMC Sonoma L4-2.2L - Vehicle Engine Mechanical Inspection - Arlington, Texas
Great overall impressions. Vechile is driveable and runs terrific now.

Damian

11 years of experience
430 reviews
Damian
11 years of experience
Ford F-100 V8-4.8L - Car is not starting - Satellite Beach, Florida
Very diligent

Duane

25 years of experience
498 reviews
Duane
25 years of experience
Chrysler 300 V6-2.7L - When I slow down and stop the car, engine shuts off - San Diego, California
Duane, new exactly what was going on with my vehicle and fixed it right away. He is my go to mechanic he very knowledgeable and always tells me what i need and how long i have to get things serviced. I definitely recommend Duane to anyone and everyone looking for a great mechanic

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

How to Replace a Timing Belt
Timing belt replacements are a common automotive technician job. Find out how to replace the timing belt on a car with this step-by-step guide.
How to Remove, Install, and Adjust Ignition Timing
Ignition distributors help spark the gas and air in the engine. Worn distributors need to be removed to be cleaned to maintain proper ignition timing.
How to Adjust Timing on a Car
A well timed ignition will allow the engine to run powerfully and efficiently. The timing needs adjustment when the engine runs too lean or too rich.

Related questions

I need to know what's the rattling noise the engine makes when I turn on the car

I would have to hear the noise to know exactly what the noise is since I have seen a serpentine belt tensioner make a knocking noise on these engines and it is an inexpensive repair to just replace the tensioner...

My timing belt broke, is there a chance there is no damage? 2000 Dodge Neon

Unfortunately, the valves are most likely bent along with possible piston damage. The 2.0ltr in both single and double-overhead-cam configurations are interference engines. The valves and pistons occupy the same space. The job of the timing belt is to keep...

The 8th digit to my honda civic LX sedan is 5, its a single overhead cam, 1.8A engine, what are the timing marks?

Here is the directions for replacing the timing chain. The manual groups all 1.8 engines together and you will need to pick the one that is for your engine in the timing chain instructions. (https://www.dropbox.com/s/xsdbtde3mw1vd39/2015%20honda%20civic%20timing%20chain.pdf?dl=0)

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com