Q: Backfiring under hood 2008 Chrysler 300

asked by on February 27, 2017

I have a 2008 chrysler 300 2.7 Changed spark plugs on car. After i put it back together and started the car up, it started to backfire under the hood. I thought maybe it could need new ignition coils now that spark plugs were new. So i changed all 6. Its still back firing. What could have caused it to back fire and how can i resolve it. It wasn't back firing before i changed anything on it. Please help.

My car has 197000 miles.
My car has an automatic transmission.

Engine is backfiring Inspection $79.99 - $89.99 Get a Quote

Hello it sounds like perhaps one or more plug wires were not re-attached in the correct order. This is especially easy to do on an engine like yours that still has plug wires routed all over the engine. The firing order, which should be on a label somewhere under the hood is: 1-2-3-4-5-6 (believe it or not), and #1 cylinder is the front cylinder, passenger side of the engine. For assistance with this problem, I recommend a backfiring inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

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

On a 2008 enclave there is a p0018 code. How do you know if it's a failed sensor or timing chain?

Hi there. Locate the crankshaft position sensor and check for power to it with the key on. If there is power, then with using a paper clip to back probe the wiring with the plug installed on the sensor, check...

Drove car with little 2 no oil & made pop noise & started smoking then adventually died

Little to no oil may have damaged internal engine components. Timing chain tensioners for example, are typically oil pressure fed. They rely on the proper oil level and pressure to maintain correct tension on the timing chains. Incorrect tension can...

Control arm bushing replacement

The service that you are referring to, namely control arm assembly replacement includes the bushings. That control arm has two bushings in it, already pre-installed in the control arm. So, the price is "complete". If you want this service performed...

Diesel in gasoline tank

Yes, this can happen from time to time. The entire fuel system will need to be drained and flushed, the fuel filter, which is in the fuel tank as part of the fuel pump, may need to be changed. The...

Battery not staying charged

Hello. The battery is basically a storage device that requires constant charging from the alternator. I would have your alternator tested. If the alternator is not the problem, I would check for a parasitic draw. This happens when something in...

Exaust smell coming through car vents, especially when idle. Engine has a clicking noise since having the spark plugs replaced.

From what you've described it sounds like there may be a loose spark plug. This would cause both of the issues you are describing. The clicking is the exhaust gas escaping through the spark plug hole, which also allows this...

Abs+brake warning at engine start

When you first start the vehicle the systems lights should come on and then go out. This is the system doing a self test. If there was a problem then one or both lights would stay on. As far as...

My windshield wipers only have one speed

Wiper speed not changing with settings can be caused by a couple of different things. The wiper switch may have broken mechanical contacts or broken electrical circuits internally. Also, the wiper motor may have electrical issues. AN internal resistor may...

2008 VW Jetta AC not cold

Hi Allen. By far the best way to have your AC system correctly diagnosed is by having an AC inspection completed first. By having one of our professional mobile mechanics come to your location to diagnose the issue correctly, it...

Related articles

How Often Should Spark Plugs Be Replaced?
While your engine runs on gasoline, it also requires electricity. It’s needed to operate most of your accessories, but is also required to...
What Does a Spark Plug Do?
Your Your ignition system is pretty complex, and there are a number of important components that must work with one another to crank the engine and then keep it running. Your spark plugs are among the most important of these,...
How to Gap a Spark Plug
The The spark plug is used to ignite the air/fuel mixture inside the engine. The spark plug must be in good condition and must be properly gapped for proper engine performance. The...