My Dodge is consuming oil at the same rate it did before I did the plenum repair. I have to put in a half quart about every two days, and that's less than fifty miles of driving. I am also noticing that the oil is very dirty on the dipstick. It literally looks like the oil you would find in a diesel motor. I've changed the oil twice since the plenum repair and it only maintains a "clean" appearance for a couple of days, then gets dark and runny. I'm wondering if I'm closer to grenading this engine than I thought...

I want to change to Rotella 20w50, but I'm wondering if this could cause more harm than good.

 

I think your best bet is to do a compression test to see where you stand. Do a dry test and then a wet test (squirt a couple of ounces of oil into each cylinder before testing). The wet test will tell you if the rings are worn.

When you take all the plugs out (they all have to be taken out before you do the test, and make sure the throttle plate is wide open, and the coil unplugged), keep track of which cylinder they each came from, and study them carefully for clues about how your engine is running. Burning that much oil, I'd expect them to be a little bit fouled. Might as well put in a fresh set of plugs while you're at it; $15 well spent since you're pulling them anyway.

Blow out the heat shields with compressed air before you remove the plugs.

 

Ok. Hopefully my buddy still has his tester. We just put plugs in it a couple weeks ago when we did the plenum.

 

It could be a cracked head or leaking gasket letting a small anount of colant in

 

+1 on compression test. Was there any oil on old plugs when you pulled them?

 

No. One of them was a little sooty when we pulled it, but nothing out of the ordinary. The plugs hadn't been in too long, maybe three months.

 

How are you valve cover gaskets? Rear main seal? Timing cover gaskets? And lets not forget the end seals on the intake manifold.... Another possibility is the PCV valve having to high of a flow rate. (get one from the dealer, less than ten bucks.)

 

It's an oily engine on the outside, but no more so than most other trucks that age. If the truck were to sit in one spot for any amount of time, there is nothing on the ground. I would think if I was losing that much oil I'd see it on the ground.

The other morning I fired it up and headed to work. I looked in the mirror and I'd swear I saw a blue plume of smoke following me around for at least a mile or so. Haven't had that since the plenum issues.

So, my buddy is thinking valve guides/seals. Tonight I came home and changed the oil, dumped some Rotella T 15w40 in it. See if it likes a thicker oil.

 

Probably valveseals. If you only have blue smoke for a mile or so when firing it up, it is valveseals. As the truck sits, oil pools in the cylinders until it is burned off. Then the process repeats itself after the truck sits and is restarted.

New head time

 

I'm doubting that most of your problem is valve stem seals. My Jetta has needed them for a long time; puts out a big ol' cloud of blue smoke on every cold start; and hardly uses any oil between changes. You're using a quart in a hundred miles, or 8 gallons between changes.

Does it smoke all the time? With valve stem seals, you usually get a big cloud, then it clears up quite a bit.

And if your seals are bad, it's not too bad a job to replace them without taking off the heads. Hooking up compressed air to each cylinder holds the valves up really well.

How many miles on this truck? Gotta do the compression test.