Q: What is causing my engine misfire?

asked by on November 13, 2016

my 1995 mercedes c180 developed a missfire i have changed the spark plugs it is still the same. a mate who is a qualified mec said it could be a burnt out valve but did a pressure test and every thing came back ok. he said it was the coilpack he replaced it and the problem still there. with the old coilpack he said it was missfireing on no4 plug with the new pack he said it is doing it on no3. so i have ordered another one . is he missing something????? any help wpold be appreciated

My car has a manual transmission.

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Ignition key won't turn

My car cranks but won't start. I can hear it trying to start and then there is a single thump noise.

There are many causes of hard starting but illustrative ones are a faulty engine coolant temperature switch (sensor), worn spark plugs, inadequate fuel delivery or pressure (e.g., clogged fuel filter), dirty fuel injectors, contaminated or old gasoline, malfunctioning idle air...

Will the code po171 effect the emissions test?

Hi Cassi. Thanks for sending us a message tonight. Yes, the P-0171 OBD-II trouble code indicates a lean mixture issue, which will impact the pass/fail of most emissions tests. Depending on where you live, any check engine light or code...

2008 Chevy Impala 3.5 reduce engine power I have changed out the oil pressure sensor throttle body and the camshaft position senso

Hi Twan. Thanks for contacting us today. A Reduced Power light usually indicates a fairly serious problem with the throttle system. When this light illuminates the vehicle will often go into a “safe mode”, which will severely limit the speed...

Oil light goes off and on.

This light will usually come on when one of two things are happening. Either the motor is in fact low on oil or the oil pressure sending unit is not working properly and may be producing a faulty reading. I...

Car starts, then stalls in one second.

Hi there. This can be a computer issue, but from the codes and the issue it sounds more like a voltage problem. If there is low voltage from a bad battery or a bad connection then the vehicle will act...

I have a 2010 saturn outlook XE AWD, I have noticed that my temperature gauge goes from 210 to 235 while I drive over 70 mph

You may have a problem with the radiator not flowing through all the channels and this will cause the engine to run hotter at higher speeds. You may also want to check the radiator cap to see if it is...

Battery dying when I don't drive car very often

If you do not drive your vehicle very often, and when you do it is only a short drive, then yes the mechanic was correct. The battery will last a about a week before needing to be recharged with enough...

Thunk sound when shifting

Hello. This is a common issue on this vehicle. If the transmission does not appear to be slipping then you either have a failing driveline coupler or a bad transmission mount. Over time both of these can rot out and...

Related articles

How Long Does a Fuel Return Hose Last?
Most Most of the older cars on the market have a carburetor that helps to disperse the fuel that is need during the combustion process. While these carburetors are very reliable, there are a number of repair issues that can...
How Long Does a Fuel Injection Line Last?
Most Most car owners are unaware about just how complex their fuel system is. In order for a car to run and operate as intended, many different components will need to work together. The fuel injectors on your car deliver...
The Check Engine Light Demystified
Your car Check Engine Light can mean many things. The Check Engine Light comes on when there's an electrical or mechanical problem with your car.