Has a new mds lifter bit the dust?!

[CLFitzpatrick0103]

Just replaced injectors and now the truck has a misfire on cylinder 4. Started immediately. Just rebuilt the whole top end of the motor, plus upgrade on oil pump, new timing chain and gears, new mds solenoids, cam, lifters, push rods, lapped valve seats all about 6months ago. Could the MDs lifter on #4 gone bad already.

 

[jws123]

Check your push rods its common to miss the hole or have it not clicked in all the way on one cylinder causing a msifire remove valve cover and confirm they all move and are seated. Did the truck have a misfire before replacing injectors? what was your reason for replacing them? I would still confirm that injector 4 is firing ect.

 

[Burla]

Did you hang spin engine after you buttoned it up? If you push rod went out of cup you would be ticking most likely. How much of a chance did you give it? Start a couple times after clearing it and still showing up?

So your truck ran fine for 6 mos but replaced injectors and now pulling p0304? I think it's the injector if all that is correct. Did you upgrade injectors or went OEM?

 

[Ken226]

Just replaced injectors and now the truck has a misfire on cylinder 4. Started immediately. Just rebuilt the whole top end of the motor, plus upgrade on oil pump, new timing chain and gears, new mds solenoids, cam, lifters, push rods, lapped valve seats all about 6months ago. Could the MDs lifter on #4 gone bad already.

Why did you rebuild the top end to begin with?

If it was a lifter failure that caused the rebuild, how thoroughly did you check the oil control valve, MDS solenoid screens, oil filter, pump and oil pan for metal debris from the original cam lifter failure?

The primary reason Chrysler recommends engine replacement if there is ANY metal in the VVT solenoid is because any debris left in the oil system will result in a quick subsequent failure when that debris makes it into the new parts.

 

[CLFitzpatrick0103]

Originally misfire on 3. Research led me to remove engine and replace everything I mentioned earlier. Cam lobe on 3 had a deep groove and scarring on other lobes. I did remove oil pan and replace gasket and thoroughly cleaned oil pan. Oil pick up tube and screen cleaned. BTW the injectors weren’t replaced at the time of rebuild. I did take them out and “service” them and they e been good up until recently.

 

[Wild one]

Originally misfire on 3. Research led me to remove engine and replace everything I mentioned earlier. Cam lobe on 3 had a deep groove and scarring on other lobes. I did remove oil pan and replace gasket and thoroughly cleaned oil pan. Oil pick up tube and screen cleaned. BTW the injectors weren’t replaced at the time of rebuild. I did take them out and “service” them and they e been good up until recently.

Did you use OEM lifters or aftermarket lifters. Aftermarket lifters have a rep of failing in a short time frame.

 

[Ken226]

Originally misfire on 3. Research led me to remove engine and replace everything I mentioned earlier. Cam lobe on 3 had a deep groove and scarring on other lobes. I did remove oil pan and replace gasket and thoroughly cleaned oil pan. Oil pick up tube and screen cleaned. BTW the injectors weren’t replaced at the time of rebuild. I did take them out and “service” them and they e been good up until recently.

Primarily Chrysler recommends the VVT oil control valve screen as the first check for debris when deciding whether to repair or replace. Was the oil control valve screen and MDS solenoid magnets contaminated?

To check the injectors, swap #4 injector with another and see if the misfire follows or stays. If it stays, do the same with the coil. It it still stays, pull the valve covers and check the rockers for range of motion. If a cam lobe is worn badly enough to start causing misfires, you'll be able to tell. You can check the pushrods while its open.