I recently bought a 1998 Ram 1500 with a 5.9 and 79000 miles on it. We noticed the spark plug wires were the originals, so we decided to do a tune up on it. Everything went well for removal until we got to cylinder 4. The metal sleeve that goes around the plug and end of the wire was messed up down around the hex head part of the plug and the socket wouldn't go down over the plug. Eventually, after many hours with hammers, screwdrivers, and pliers we got the sleeve off and were able to get a socket on the plug. Unfortunately it was seized in the motor and sheared off the head. We used a broken bolt removal tool and were able to get the rest of the plug out. After inspecting the pieces of the plug compared to one of the others, it looks like we got everything out, and no large pieces fell into the motor. We left the plug out and cranked it over a few times to blow any little bits that might have fallen in out. We then installed the new plug, and finished the wires, cap and rotor.

When we fired the truck up there was a tapping sound coming from the engine. It varies in speed to match the rpm, but doesn't seem to change in volume. Oil pressure seemed good, it's up over 40, however the "Check Engine" light is on. The truck seems to run pretty well otherwise, just making a loud tapping noise. My brother seemed to think it was coming from the head area on the passenger side, but wasn't positive. We finished up around 11:30 last night, and plan to give it another go this evening, but I thought I would see if you guys have any ideas. My brother is a fairly experienced mechanic, but Dodge engines aren't his specialty, and he was at a bit of a loss as to what the issue could be. He is going to bring home his code reader and stethoscope from work tonight so we can see if we can narrow it down a little.

The only other slightly related thing I can think of is that I changed the oil earlier in the day. After draining the oil I went to remove the oil filter, only to discover that the previous owner was He Man and I couldn't get the filter to budge by hand. I didn't have a filter wrench that fit, so I just refilled the truck with new oil, and will do the oil change again next weekend after I pick up a filter wrench. The truck ran well after the change, and got driven around 30 miles before the attempted tune up.

So... anyone have any ideas?

 

Take out the number 4 spark plug, and run the engine for a few seconds. Chances are, it will spit out whatever is in there. (just cranking doesn't build up the air velocity ya need.) A chunk of metal bouncing around inside the cylinder makes a heck of a racket.

What codes are you getting for the CEL?

 

I forgot to include that. After the tapping started, we took the #4 plug out and started it up and let if run for a new seconds. Something got blasted out, but I don't know if it was out of the cylinder itself, or just some of the loose rust from around the hole for the plug. After we put everything back together the tapping was still there.

 

Wonder if there is more in there......

Got a stethoscope? Might want to see if you can't isolate the noise a little better.

 

My brother is supposed to bring one home from work so we can do that, along with his code reader.

 

Was just reading this thread:

https://dodgeforum.com/forum/2nd-gen...-knocking.html

Looks like a tapping/knocking issue was fixed by fiddling with the crank position sensor. It sounds like it's located near the trans dipstick. I was doing stuff in that area routing the wires. I suppose it's possible I bumped the sensor or something. Anyone have any thoughts?

 

Just thought I'd give an update. We messed with it some more tonight. We finally got the stuck oil filter off, so we installed a shiny new Mopar oil filter, and a fresh 5 qts of 10w-30 oil. Didn't make any difference at all for the noise. I watched the oil gauge when I started it up. It sat at 0 for a second or 2, then went up to 40 and paused for a tick, then went on up to 50 or 60ish and sat. Through all of that, the tapping noise didn't miss a beat, and didn't change tone or volume in the slightest amount.

Next my brother broke out his stethoscope and checked around a bunch of places and couldn't really narrow it down to one side or the other. He said it sounds to him like it's coming from the center of the engine.

To try and rule out the bottom end, while it was running he disconnected the injectors one at a time to see if the sound changed at all. He went through all 8 and the sound didn't change. His reasoning is that the knocking you get when a rod bearing or something goes bad occurs when the fuel detonates and pushes the piston back down. So if the fuel was cut off, the sound we hear would either change or go away if the cylinder it corresponds to isn't getting any fuel. This didn't change the sound at all.

I also tried shifting it into and out of gear to see if it might be transmission/flexplate related, but that didn't change the sound at all, other than the slight change in engine rpm.

The only thing we were able to do was get it to go away momentarily by playing with the throttle. He was messing with the throttle while listening, revving it up, and down, and just kind of playing with it, and at one point the tapping went away completely for a second or 2, then tapped once or twice again randomly, then came back again. We messed with it some more, and couldn't get it to do it again.

As another test my brother pulled the coil wire, then had me crank it for a few seconds while listening, and we didn't notice the tapping noise, so it only occurs while the truck is running, just turning it with the starter isn't enough.

Unless someone here or a friend of his has a crazy idea, our next step is to pull the valve covers and see what we can see, because we feel that it is most likely something in the top end of the engine. Possibly a sticking valve or lifter because of some kind of debris that managed to get in there. Unfortunately that won't be until friday because he has to go to Pennsylvania for training (he is a Kia mechanic at a local dealership). He's going to try to call his friend who is an ex-Dodge mechanic and currently owns a truck customizing shop and see if he has any ideas.

So, if you guys have any ideas, I'm happy to hear them.

 

I would check the lifters

 

Yanking the valve covers and inspecting there sounds like a good plan. So far, you guys are doing everything right.

 

The thing that bothers us the most is that doing an oil change and a tune up shouldn't have caused this issue. We're very confused about where it came from because the truck ran great until after we finished changing the plugs and wires. No odd noises at all.