At Fixya.com, our trusted experts are meticulously vetted and possess extensive experience in their respective fields. Backed by a community of knowledgeable professionals, our platform ensures that the solutions provided are thoroughly researched and validated.
I have a 99 gmc yukon denali. it has a multiple cylinder misfire, uses coolant, no visible leaks. and my spark plugs look black. i have gave it a full tune up. (plugs,wires,cap,rotor,and coil.) i am thinking my problem was head gaskets or intake gaskets. i have also replaced the upper intake. what is wrong with my motor?
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
P0300 indicates a random or multiple cylinder misfire. With the engine running rough unplug one coil at a time while listening for an RPM change or for the engine to run even worse. If there is no change from one or more coils than check those coils for spark. If there is no spark out one of the coils swap it with another coil. if there is still no spark replace the coil.
This is AFTER the intake repair? or did you do this to try to fix the misfire????First you will need to check Injector Flow to the #6 cylinder. A TECH2 scanner is required, Most likely the injector may need to be unclogged with high pressure air or nitrogen.
TRY LUCAS OIL,I USED A FULL LITRE FIRST,WILL LET YOU KNOW HOW IT WORKED.BEFORE THIS I CHANGED OUT TWO ROTTEN LOOKING KNOCK SENSORS,THEN TWO WEEKS LATER REPLACED THE REAR ONE AGAIN,AND IT FAILED AGAIN.AND SO I AM NOW TRYING THIS NOTICED A BIG DIFFERENCE IN POWER NOISES,NO PINGING,NO RATTELING LIKE IT IS A DISEL.
it could be alot of things...you could start by routine maintnence( new spark plugs, spark plug wires, air filter, oil change, the in line fuel filter) also take into consideration what kind of gas you are using...i know it sucks spending $100 a week in gas with your AWD 6.0 liter V-8...but if ur not running premium it could very well be your problem. I have also heard of the denali's having oxygen sensor issues...is it throwing a check engine code?
×