Hi new here I have a 94 ram 1500 with 318 with 170,000 miles on it.
now wene i start it up puff of blue smoke comes out and if it idles for a while like at a red light soon as you give it the gas to go big puff of blue smoke. i pulled all the plugs out and all are clean except #8 cyl has like a rusty color to it rest were all white. checked the intake pan gasket by seeing if the crankcase has vacume on it and it don't builds up presure if you check it by disconecting pvc and blocking off the pasages so do not think its the pan gasket. think it might need the heads pulled and checked .
compresion was between 165 and 175 on all cyls anyone have any ideas?

 

Burnin oil, blue smoke! The heads on these do tend to crack, so thats worth a try. Could be lots of things, worm valve stem seals, piston ring seals. The lsit could go on. Whatever it is its usually not good [&:]

 

blue smoke it thought blue smoke was coolant and black smoke was oil... eeerrr wait... blue smoke is oil and white smoke is coolant.... damnit i cant rememeber wahts it smell like

 

Blue or black smoke is oil white smoke is coolant. Shott you are having soom serious brain farts today PU!! Speeddemon if you have never used it try this Autozone. Autozone has a section for trouble shooting. This link will take you to the section where you need to look.

 

When the truck has been sitting for a while, with these trucks in particular, if the PLENUM GASKET goes it will let out a puff of blue smoke. Take the air hat off and open the butterfly valves and look down into the intake manifiold through the throttle body with mirror and a flashlight to see if there is any oil pooling up inside, if there is the plenum is gone. You said it gave a puff at a stop light, how much oil are you losing??? It could be possible for there to be a really bad leak in the plenum. You said that the plug in cylinder 8 was not looking good, that is the back right in the plenum pan so the oil will go there first. Do not wait too long to get this fixed, when i bought mine the plenum had a leak and i do not know how long the previous owner had it like that but it burnt up one of the cylinder 8's valves. I do not think it is the valve seals, those will usually last a long time in these, unless the truck has been sitting for a long time, but its probably not the valve seals, my vote is the PLENUM.

Blue smoke= oil
White smoke= coolant
Black smoke= unburnt gas (runnnig really rich)

Good luck

 

Its useing about 1 quart in about 3000 miles. thought if the PLENUM GASKET is bad you would have a vacume condition inside the eng i am getting presure inside this one but will look inside there anyways too see if oil is in there don't think its rings truck still has lots of power

 

Checked out the Intake looked down inside no oil so ran a vacume hose in and pulled it out with wet oil on it so oil is in the back of the intake so will have to get it fixed

 

as others mentioned, check the plenum. the blocks are pretty tough and should easliy go 200K+ miles. the heads do crack between the valve seats but that shouldnt cause any oil issue, it'll cause a miss that you cant fix w/o swapping the heads.