I have a 97 ram 1500 4wd 5 speed RCSB. I got the truck for 300 bucks with 185000 miles. The only problem it had that I knew of was that the driveshaft was bent. I picked up a new driveshaft, but not before I happened to look inside the rear differential and find chunks of metal. So I threw a 4:10 rear end in it. But since I got it running, I have noticed that it burns oil. BAD. Every two weeks, I put at least 5 quarts in it. That is also about how long a tank of gas lasts. I checked the spark plugs to see if it was one or two cylinders burning it, but all the plugs showed signs of burning oil. I checked down the throttle body, and it looked wet, but there wasn't oil puddled up, so I don't think the plenum is bad. Are there any ideas why it is burning so much oil?

 

If it hasn't been fixed, the plenum is bad. Look toward the back of the intake, see oil pooling there? (may need to remove the throttle body, and use a mirror.)

Valve seals are probably also shot. (not a big deal to change, just tedious.)

Rings would be the next thing. Do a dry/wet compression test. See what the numbers do.

Leaving puddles anywhere?? How's oil pressure?

 

I hope you changed the front axle to 4.10 as well. If plenum is good, rings and valve guides could be worn. 5 qts every two weeks means something seriously wrong.

 

My first 98 would burn 5 QTS in 5-7 days. After changing everything I could on the motor I found out the rings were shot. Replaced the motor and never had another problem. That truck only had 88xxx miles.

 

Well, i dont think i have the gauge for a compression test, but Ill see if i can get ahold of one. I guess i didnt look far enough back into the intake manifold to tell if the plenum was shot. Looking through the throttle body, it looked wet, but no puddling. I just figured with all 8 plugs showing signs of burning oil, the rings or valve guides wouldn't be bad on all 8 cylinders. But i suppose i could be mistaken. And no, i didn't change the front to 4:10. I dont have the money at the moment. I got the axle assembly for free. I could switch the rear back to 3:55 here soon, but i really like the 4:10

 

Switch the front to 4:10 when you can afford it. Don't use four wheel drive until you do though.....

Most parts store will rent you a compression tester.

Valve guides and rings are all lubricated by the same oil, so, if it wasn't changed as often as it should be, then everything was subjected to crappy oil, and will all wear at pretty much the same rate.

 

I see what you are saying. And i forgot to answer your other question. Oil pressure drops to 0 whenever i shift to neutral or at idle, unless its cold when it idles slightly higher. But when it is warm, it shows zero oil pressure. Also for the front end, to get it rebuilt and regeared is 850 at the shop I trust, so it'll have to wait. I do have access to a 3.55 open rear end, but i don't think I'm gonna go back

 

Does oil pressure jump right back up if you give it just a little gas? Might just be a bad sending unit.

What's your oil press. when running down the road?

 

Oil pressure when in gear or when i give it some gas is at a normal range. You guys mentioned that a blown plenum would cause awful gas mileage, when in fact im getting about 15.5 mpg. It is also losing coolant at a noticable rate, which would lead me to think a blown head gasket or cracked head, but idk. I dont even know if it is burning it. The exhaust should smell kinda sweet, correct? All i smell is burning oil.

 

Im having the same oil usage problem you are. replaced the plenum gasket, but not the cover and still adding a quart every 50 miles without smoke in the exhaust and no oil in the intake. Valve stem seals or rings are your next things to do after the plenum, and i would upgrade to a hughes plenum plate to make sure that isnt your problem. my dry compression readings on my 5.9 with 176XXX are 125-135. WHen i do the valve stem seals Ill post and let you know how it turns out.