Skip the auto shop - Our mechanics make house calls

Q: Cylinder #6 misfire on 4.0 liter SOHC

asked by on

I've replaced EGR plugs wires TPS idle control valve coil MAF sensor still show #6 misfire starts and runs but had vibration at 55 mph do u have an idea what this could be and has been wrong with similar vehicles cost to fix? Thanks Dan.

My car has 212000 miles.
My car has an automatic transmission.

A: Hello. Good job on getting the basic tune-u...

Hello. Good job on getting the basic tune-up work done! Given the mileage, this engine may have a longer-term issue, namely, accumulated wear on piston rings or a blown head gasket. Both of these can be diagnosed with a compression test, or a leak-down test if compression numbers are more consistent than engine running suggests. If the miss is constant and regular, a burned valve is also a good possibility. I recommend having a professional, such as one from YourMechanic, inspect the misfiring issue in person to diagnose this problem and assist 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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Clutch slave cylinder

Hi, thanks for writing in. If your slave cylinder is leaking in this vehicle, I would not recommend driving it at all. It is very likely that within just a few applications of the clutch, you could lose all of...

Q: My car does not move when I accelerate, the engine shakes when it is turned on and in a traffic it shakes sometimes.

Hi there. Check the engine for any misfiring conditions. Check the spark plugs and the fuel injectors and see if they are working properly. See if there is spark to the engine and see if the injectors are firing by...

Q: Power Steering Pressure Switch discontinued...

Thanks for writing in. You may not have considered moparrepairconnection.com or rockauto.com, both of which show this part as available. If you need help with this replacement, a YourMechanic certified mechanic can perform the power steering pressure switch replacement at...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.