Q: Engine knocks
The engine knocks on my vehicle.
Engines can make a lot of different noises when there is something wrong. If it is extremely loud and consistent, your engine will need replaced. If it is ‘knocking” when the engine is cold and is quiet when it’s warm, it could be “piston slap”. This is worn cylinder bores and piston skirts. If the noise is only when the engine is hot, it could be “pinging”. Also known as pre-combustion, or detonation. This happens when the engine is overheating.
The statements expressed above are only for informational purposes and should be independently verified. Please see our
terms of service
for more details
Get an instant quote for your car
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing
What others are asking
Surge of acceleration when brake pressed
There is currently no approved safety recalls or Technical Service Bulletins (TSB) for the 2012 RAV4 that address this issue. In the past, there have been 2 recalls, NHTSA Campaign #11V113000 and NHTSA Campaign #10V017000, but these have not been...
Car overheating and not accelerating
As far as the thermostat causing the motor to sound muffled, I personally have never heard of such a thing. Your thermostat controls when the flow of coolant in your cooling system starts, allowing the coolant to flow and cycle...
What kind of oil change do I need?
Hi there, thanks for writing in. I'd be happy to offer some insight about these services for you. It's usually a matter of personal preference and driving style. Synthetic oil is designed primarily for high mileage and high performance engines...
Car began knocking after an oil change, then exploded blowing 2 holes in the side and the oil pan off
It may be hard to figure out why the engine failed without knowing if the oil leaked out or was not filled up. I have seen situations where after performing an oil change the oil leaked out from an oil...
Car won't start. When trying to start, starter makes a clicking noise and then closed back hatch recloses.
It sounds like there is some type of drain on the battery (https://www.yourmechanic.com/services/battery-will-not-hold-a-charge-inspection). When there is low voltage in a battery, it can cause several symptoms. The electrical systems can act very strangely when they don't have the correct voltage...
I have a engine miss codes po174 po420 are on now I had code multiple cylinder miss fire. I changed spark plug wires and plugs l
Hi there. Your issue might be caused by a faulty O2 sensor. You might want to read this article about the P0174 OBD-II trouble code (https://www.yourmechanic.com/article/p0174-obd-ii-trouble-code-system-too-lean-bank-2-by-blake-griffin) as it will show you possible causes, symptoms and solutions to resolve the problems....
largest motor for 2008 chevy cobalt
The hardware and software of the computer (powertrain control module) and transmission control module (TCM) in the Cobalt will only work with your present engine. If you change the engine to one that is not a catalog interchange for the...
Just bought a 2017 altima and I'm hearing a scraping sound when I step on the brakes what is wrong with my brand new car? And will
Hi there. I would seriously doubt that you have brake damage, but this is something that you should immediately bring to the attention of your Nissan dealership where the car was purchased. It's possible that there is a leaf or...
Related articles
What Is the Purpose of Engine Gaskets?
Engine gaskets work as seals to maintain pressure, hold fluids, and prevent debris from entering the engine. Gaskets are vital for engine performance.
How to Find Top Dead Center
There There are many reasons why you might need to find an engine’s top dead center. Top dead center is the point when the piston of the number one cylinder in an engine is at its highest point, and on...
Subaru Certified Pre-Owned (CPO) Car Program
If If you’re in the market for a used Subaru vehicle, you may want to check out cars under their certified pre-owned program. Many manufacturers have a certified pre-owned (CPO) program, and each one is set up differently. Read on...
Browse other content
Estimates
Maintenance