Hi dodge friends, I am looking for some help finding this annoying vibration in my motor. It is most notable around 1500-2000 RPM, but can still be felt through out the every RPM.I have changed the plugs and the old ones looked perfect so then I changed the plug wires, cap and rotor, did noting to help. I also changed the plenum gasket because it ats about 2 quarts of oil every 3000 miles still nothing and it still eats oil. If anyone has any sugestions they would be greatly appreciated.

 

Do a compression test.

 

2 quarts of oil holy crap! That means you're losing almost half your oil between an oil change, do a compression test and check the common signs for a blown head gasket. Also, check your valve cover gaskets and oil pan gasket to make sure there's no leaking there because 2 quarts is quite a lot.

I had a leak one time on a valve cover that I got cheap and put a cheap gasket on and it went thru about a quart in 3,000 miles.

 

wow my truck only uses about 1/2 a quart every 5k miles(4.7 holds 6 qts), 2qts is ALOT to loose from those engines, definitely check all the gaskets for leaks.

 

I did a compression check and I had 145 lbs on 6 of the eight cylinders and 160lbs on the other two. There are no external oil leaks at all, the motor is as clean as can be. I have noticed that I do lose some engine coolant over time, its not alot but I do have to add coolant about once a year. There is no oil in the coolant or coolant in the oil.

 

The only other place I can think of oil leaking internally would be the valvetrain.

 

Yeah, it sounds to me like your valves and/or rings are gone. If the oil doesn't show up outside it must be burning it off. Do you notice any odd smoke coming out of the exhaust once it's warmed up?

 

Ya once it's warmed up for a bit, there shouldn't be too much white smoking coming out, can't recall what burning oil smells like but I've sure it's noticeable so deffinetly check that first.
I doubt your piston rings are bad, these engines are build tough as nails and I've seen ones with 400k on them from vans still have hardly any wear on the rings, but it all depends on what gets past your air filter so don't rule it out yet, just keep it in the back of your mind. Some of your valve seals are most likely either worn or gone.

 

i hate to say it, but with coolant and oil being used, id expect the problem to be in the headgasket, even if there is no oil in the coolant or coolant in the oil, could be leaking minutely enough into the cylinder that it just evaporates and blows out the exhaust, and the oil will just burn up in the cylinder (you SHOULD see smoke from it tho, not sure why you arent, unless you just havnt mentioned it)

 

Mine always burnt a little coolant, it's not a big deal but the oil certainly is, you'd be surprised how much smoke a few drops of oil getting burned will make, once your engine is warmed up and running for a little bit the white smoke should just be noticable, nothing major, if it still always looks like it does as soon as you start the engine on a cold morning, then it's burning oil. For testing more gaskets, your best bet is just leak down tests, those rarely ever lie.