The culprit is oil collecting in the cylinder and not being burnt off. Generally it is caused by 1) leaky valve seals, 2) worn rings, 3) leaking head gasket.
The first check should be a compression test to verify if the rings or heads are leaking. If they are fine the only thing left is the valve seals. Not an easy fix but can be done by a home mechanic with some effort.
Fouling spark plugs can happen when the tip temperature is insufficient to burn off carbon, fuel, oil or other deposits and causes spark to leach to metal shell...no spark across plug gap will cause a misfire. Wet-fouled spark plugs must be changed as they won't fire. Dry-fouled spark plugs can sometimes be successfully cleaned by bringing the engine up to the operating temp.
Wear. Fouled. Cracked.
Faulty/fouled spark plugs or spark plug wires. I had this problem and a set of new wires fix it.
if the spark plugs are black because your car is running too rich. your plugs are fouled.
possible fouled spark plugs, bad fuel. check both and if both are good, get back to me.
intake manifold gasket is leaking and water is getting on the plugs, plastic piece melts and causes leak
Yes, fouled spark plugs can cause engine shaking, and loss or power. I'm not sure about knocking but I'd guess that too.
Absolutely. Worn plugs or carbon-fouled plugs can cause an engine to not start.
Possible wrong heat range of plug. Make sure you have the right plugs for the vehicle.
no The starter should engage whether the plugs are fouled or not. However, the engine may not start if enough plugs are fouled. If you feel that you have flooded the engine or fouled the plugs you may need to clean them before it will start. If you have caused the carburetor float level or other settings to be significantly changed, the engine will flood and it will not start.
You should check your spark plugs periodically as they can give an indication as to how your engine is running. If the spark plug is fouled the engine wont work as efficiently as it's supposed to. A normally operating engine should result in a light brown discoloration, check your spark plugs against a reading chart like http://www.ngksparkplugs.com/techinfo/spark_plugs/faq/faqread2.asp If the spark plug is fouled or eroded, replace it. It's a simple job and spark plugs aren't too expensive.
Spark plugs do not loose power, rather, they become worn and erroded. On occasion they may also become fouled, indicating a mechanical or fuel problem.
If you have good power when on highway and it only hesitates at low speed or from a stop you have a weak spark somewhere. Possible causes: Needs a tune up Fouled spark plugs Old plug wires Ignition coil about to die improper timing
If the spark plug or plugs are bad the car will not start If the car does not start, (for various reasons) the spark plugs may be fouled or damaged by this and require replacement.
Spark plugs are cheap so, when you pull them to read them, don't put them back in. Replace them with new. To read the plugs, you need to compare them to the pictures at the link. They will tell you about your engine's health. Fouled plugs are not the problem, they are the symptom.
No spark from coil, bad plug wires, or bad plugs.
spark plugs fouled with oil. blue smoke from tail pipe.
You have to remove them and inspect.You have to remove them and inspect.
Have the codes checked to know possible causes.Have the codes checked to know possible causes.
if it's runninng rough my guess could be spark plugs are fouled up. if not then next check the spark plug wires then the distributor.
If the spark plug is fouled ("too rich" or in other words: Too much fuel, not enough air or spark to ignite): It is possible that the rich fuel will dirty up an O2 sensor, which may trigger a P0420 error.
only if the plugs and wires that replaced them where not fouled most time yes is the answer. after changed start the vehicle and it should be aparent.
There are many possible causes. Including, worn spark plugs, failed oxygen sensor, leaking injector, improper reading from the MAP or TPS sensors, etc.There are many possible causes. Including, worn spark plugs, failed oxygen sensor, leaking injector, improper reading from the MAP or TPS sensors, etc.
Could be as simple as fouled spark plugs.
Sparks plugs deteriorate or become fouled over time. Replacement spark plugs are spark plugs you buy to replace the old ones. What the gap is supposed to be set at.. that varies by vehicle. If you're trying to do this, and you don't know how, I'd very strongly suggest you buy a Chilton or Haynes service manual for your vehicle.