Engine misfire?

Question

i have a 1997 mercedes e320. i diagnosed the code, it said cylinder 3 , and 5 misfire. what could cause this? thanks guys!

Answer 1

No one mentioned timing. Have a mechanic time it and go from there. If he says it was way out of time, that may be your problem.

If it's not, and he times it correctly, it should run better.

Answer 2

Most often human error. If they get anti-seize on the spark plug head or wire boot the juice will run around the plug and not through it.

If it has not had a tune up for ten years the plug gaps will all be different and some can be three to four times wider than specifications call for so the the spark flash has stopped too soon or too late when the piston is in compression position ready to fire. You're talking milliseconds on timing and if the spark has too short or too long a duration or too early or too late you'll get a misfire code. Timing is always based on the #1 cylinder and the electrical system can't adjust the spark timing for each individual cylinder so if the spark gap is off on half the plugs or just one plug you lose some efficiency and power.

Look for anything obvious on the engine by a visual inspection and then take a look at the plugs.
Most plug wires will last indefinitely but whe they go or when a coil goes there's juice jumpin got the block or head rather than running through the plug like it should. At night time you can pop the hood and start the engine and look for any spark under the hood around the wires and coil(s). If you see spark then there's an issue with a wire or coil.

You can ohms test the wires and coil(s) to eliminate them if the problem isn't obvious.

Good Luck!

Answer 3

As these two cylinders are next to each other in the firing order-1-5-3-6-2-4 ---next to each other inside the distributor cap then a likely cause is the spark is tracking across a carbon track between the two contacts

Answer 4

ALL of the above! Hope for a check engine light to come on and the error code might help diagnose the problem. Cylinder misfire can be caused by many things including ignition, intake manifold air leaks, emissions failures or maintenance needed etc.

http://www.samarins.com/diagnose/checkengine.html

Answer 5

a bad spark plug or a bad wire either one will cause this,usually its the plugs that cause multiple mis-fires like that,id try having the plugs changed and see if that helps it,it usually does,i just got done with one that did the same thing in the shop,and by just changing the plugs it fixed the problem with it,plugs should be changed every 50 thousand miles to be safe,it can also be a bad coil pack causing this to happen,but change the plugs first in it,that repairs them 99% of the time,good luck with it.

Answer 6

Vacuum leak?
Small vacuum hose came off the intake somewhere.
With the engine idling, listen for a slight sucking noise and feel and look around for a small hose that's not plugged into something.

Answer 7

Try putting dielectric grease on the insulators of plugs 3&5 and see if it cures the problem of spark tracking to ground.If that is not it,it could have something to do with debree on the crank possition reluctor wheel.

Answer 8

worn out plugs losse plug wires or broken plug wires shorting out to the engine block replace the plugs and wires chech cor a cracked distrubuitor cap

Answer 9

1. bad distributor or rotor. 2. bad spark plugs. 3. bad plug wires. 4. bad fuel injector.

http://www.aa1car.com/library/misfire.htm

check out this site. good luck, rob

Answer 10

CORROSION ON CRANK SENSOR?