I recently purchased a 2002 Dodge Durango with a 4.7L V8. After a couple weeks of beating on it pretty good as I do all my vehicles I noticed the oil pressure not sitting where it normally does. I checked my oil and there was not a drop on the dipstick. I added 5 quarts before it reached the safe level on the dipstick. Obviously it was pretty alarming that i risked blowing up my engine. The odometer in the truck reads 303k miles, I don't believe its correct though because when I crawled underneath expecting to see oil sprayed all over there is not a single drop of oil leaked, under the hood there looks like there may be a very slight valve cover leak but very slight. I believe its burning the oil because upon start ups, idling for long periods of time, and punching down the throttle, I get a strong smell of burnt oil. Also the o2 sensor for bank 1 sensor 1 is bad. I've read other forms saying that the PCV valve can cause pretty bad consumption in the 4.7s but is it possible to be so bad to burn 5 quarts of oil?

 

Can you see smoke out if your exhaust?

 

I also have a 2002 4.7 and it burns oil. When I accelerate from a stop there is a puff of smoke.
Mine has 140k on it and it runs great. This sounds like a rather common issue with the 4.7.....
I keep an eye on the oil level. never let get more than 1 qt down.
How is this issue fixed ???
Thanx in advance for any advice

 

I will check the plenum gasket

 

4.7 does not have a plenum gasket issue.

 

Any idea what could be causing this 4.7 motor to burn oil ? I can also smell the cad converter when I'm at a higher speed. 140k on it. Was gonna put on a new cad converter and muffler... couldnt hurt. I get a large plume of smoke sometimes when accelerating from a stop sign when the motor is warm. Would like to know how this oil consumption issue could be fixed...
Thanks in advance for any advice

 

iv actually never heard of an oil consumption issue on the 4.7, the 5.2/5.9, sure they plenum on those goes all the time, but the 4.7, never heard of one.

PCV valve going to bad shouldnt affect oil consumption that much, but its an easy part to replace so if you think that will help go for it and let us know for sure. as for being 5 qts low bc of that . . . only if your not keeping an eye on your oil level this is part of my SOP even on a NEW car, i dont trust the computers to tell me before its too late.

other things i would check would be to pull the spark plugs one by one to see if one of them is oil fouled, if so you have a likely head gasket leak into that cylinder. I also wouldnt replace the cat until you get the smoking issue under control bc burnt oil in the exhaust is known to kill cats.

 

I did replace the PVC valve and it was definitely bad but it didn't solve the problem. It sounds like the head gasket leak into one of the cylinders makes the most sense. When I start it up when its cold it has a bad knock for a minute or two. After that, it seems to run fine...thanks for your help. That sounds like an expensive fix...not sure what to do about it now. $$$

 

Sounds like bad piston rings.

 

I was told bad valve guides not seating