Question I have a 98 dodge ram 1500 5.9L360. Been having difficulty with the check engine light. Scan tool shows misfire on cylinder 8. Garage replaced intake gasket, new thermostat and gasket, replaced air filter, and no 8 spark plug as it had oil on it. The light is still periodically coming back on. We reset the light over month ago and it stayed off until 3 days ago. We reset it again and are hoping for the best. The truck runs good. What do i try now?
Answer Hi Barbara,
If the code is still for the number 8 cylinder missing (0308) then I would suspect, based upon the oil build-up on the plug, that there is either a worn valve guide or piston ring on that cylinder. Either of those would be expensive to repair.
What weight of engine oil are you using? One thing to try would be to increase the weight of the oil one step at the next oil change as that would reduce the in-flow of oil into the cylinder and prolong the running time before the plug gets oiled-up again.
Other than that, you could 'live' with the light/miss until it becomes a problem with the actual performance of the engine. Just periodically check the code, which you may be able to do using the ignition key: "on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window to see if the mileage reading is replaced by a 4-digit number preceded by a P which would be the fault code involved in the light being 'on'. That self-readout may or may not be available in your truck, but give it a try.
Free fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.
I answer questions seven days a week and respond to you in about 30 minutes. "Maxed Out" means I am answering another question or asleep overnight so try again later.
I have do-it-yourself experience (50+ years) and a library of 100 1982-2011 Chrysler factory shop manuals and 20 multi-manual Chrysler Corp. CD's.
I was voted "Top expert" from 2010-2015 here at AllExperts, and have answered 20,000+ questions.
Five decades as a 'do-it-yourselfer' on domestic and imported cars
Organizations Yahoo Autos Group called The Chrysler Lebaron Club (co-moderator)
Education/Credentials Degrees in Physics/bruised knuckles.
Awards and Honors "Top expert" of 2010, 2011, 2012, 2013, 2014, and 2015 here at Allexperts.
Quickest "average response time" at Allexperts (currently no. 1).