Skip the auto shop - Our mechanics make house calls

Q: My engine light is on, has increased emissions and reduced power, and car also shakes

asked by on

My car has shaken a lot since the engine light came on. I went to a mechanic and they diagnosed misfire on 7 of 10 cylinders. So they advised me to get tune up and change spark plugs so I did that. Still no change. After that I got another code saying misfire on cylinder 10 and delayed upstream o2 sensor. I drove it for one day then went back to Mechanic they read the codes again and it came up as misfire on cylinder 10 delayed o2 sensor and something about the coolant low on thermostat. They advised me that one problem was the misfire on cylinder 10, which they said was a bad coil so I let them swap the coil from cylinder 10 to another cylinder. I drove about 25 miles and the next day I took it to AutoZone they read my codes and now it says misfire on cylinder 10 and 3 and coolant thermostat (coolant temperature below thermostat regulating temperature). Please help.

Hello, thanks for writing in. The coolant temperature code can be due to low coolant or a failure in the thermostat. Most of the time this is a thermostat issue. As for the misfire problem, it is common for one or more coils to fail and cause this to occur. I usually test each coil to see if any of them are marginal. Many times on these vehicles just to prevent having continued issues with coils I change them all with the spark plugs if there are a lot of miles on the vehicle. I also do a compression test to make sure that the engine is fine internally. If there are multiple cylinders misfiring I also do a fuel pressure test because low pressure will cause this to occur. If you are looking to have your misfire and temperature codes looked at, consider YourMechanic, as a certified mechanic can come to your home or office to inspect this and make or suggest how to proceed with repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  • Home
  • Questions
  • My engine light is on, has increased emissions and reduced power, and car also shakes

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

Get a quote

What others are asking

Q: What would stop the ignition lock cylinder from going back in its casing?

Unfortunately, without physically seeing the ignition cylinder in person, it would be difficult to determine why it is unable to go back in. One thing you can attempt to do is to take your Dodge's ignition cylinder to a...

Q: Why is the check engine light always on?

You are correct that when the Check Engine light is illuminated with no drive symptoms you will not have any indicator if any more problems are happening. That is, unless another light comes on or you get symptoms you did...

Q: Location of thermostat.

Hello, thank you for writing in. While it is strange to think the thermostat can be located on the lower radiator hose, this is common practice for some manufactures. The concept works exactly the same. The coolant entering the radiator...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.