Tapping noise in my dodge 318

[dakota99]

Okay so here's the deal. This tapping noise started very faintly back in the winter but i never thought anything of it. Since then it's been getting worse and i would like to get to the bottom of it. I believe it's something in the valvetrain, either a lifter or rocker, somewhere in that area. It's not a knock, more like just a tapping noise. I can faintly feel it in the gas pedal, and if i put my finger on the passenger side valve cover i can feel it also. It changes with RPM, and at idle it's barely noticeable. If i rev the engine while parked you can't hear it, and if i let off the gas while driving it pretty much goes away. It seems to only occur in gear, whether it be driving or backing out of my driveway.

When you start the truck in the morning it sounds great, and when you put it in gear and drive off it sounds good. You can start to hear it after about twelve blocks. The truck has never been beat on or run low on oil, and it has had mostly synthetic the last five years. I switched to yellow bottle just for the heck of it, but it never changed the noise. My friend wants me to run seafoam through the oil but im very hesitant on putting a solvent in my crankcase. He thinks it's a stuck lifter. Another person thought it might be a loose rocker arm. If i drive the truck when it's warm and heat the oil up to temp, sometimes it will go away completely. It's just really weird.

Any help is appreciated.
-Colin

 

[ted s]

its a lifter

 

[wrcsixeight]

Hard to imagine a ticking lifter transmitting vibrations to the gas pedal.

 

[Dakota1820]

probably a lifter.

 

[Chris142]

it has a non adjustable valve train. of it's a valvetrain problem it could be a bad lifter,bent pushrod,worn pushrod ends or worn rocker arm. another common noise maker on those was a worn lower distributer bushing or loose flexplate bolts.

 

[Jimmy9190]

Could be the evap purge solenoid. I believe on that year of Dakota's the solenoids were mounted on the firewall. When they go bad they can make a tapping noise like that. I have read on the Dodge Forum of others having that problem. At least it's a possibility that may be worth a look.

 

[dakota99]

I looked everywhere else under the hood and it's definitely coming from the engine. I'll order a bottle of auto rx just for kicks, I guess it can't hurt. It seems safer than seafoam. If its a bad lifter or pushrod I'll have to save my money.

Will driving it like this lead to a more serious problem? It seems like some days it's worse and some days it's not as bad.

 

[dakota99]

Well i put the auto rx in today, we'll see what happens. I don't rack up a lot of miles so it may be some time.

 

[mechtech2]

Even non adjustable valve trains ARE adjustable.
With different pushrods, or grinding the valve stem, or using a shim cap. Maybe even a new rocker.
The fact that heat makes the noise appear indicates a clearance is opening up - this is not a leakdown problem.

That 318 is gonna run another 100,000 miles, either way!

 

[BAJA_05]

What have your results been with the 318 and your engine noise?

 

[dakota99]

Well i just found this thread again. The auto-rx didn't do much of anything, the oil didn't even look dirty when i drained it out a little over 3000 miles.

Someone suggested MMO in the oil but honestly i'm not sure it would help. I feel i should just park it while it's nice out and tear it apart to replace the lifters. If i do i figure i might as well replace the pushrods too.

I hate to take that intake off again but if it has to be done, oh well.