So its a 98 5.9l with the hughes intake, new pcv valve, and has started to smoke under high vacuum. I can't see it smoke when I'm decelerating under normal condition but a friend that was following me said he can. However if I put it in second gear at 60-65mph and totally let out of the throttle I have a james bond style smoke screen. Now at WOT nothing, its only under high vacuum when you're slowing down. So has anyone else had this issue? A friend suggested valve stem seals. I'm kinda lost. Oh it idles smooth as butter and has no hint of a missfire. Popped the radiator cap and no bubbling so no indication of a head or head gasket problem. Truck is approaching 161k.

 

Disconnect the the pvc valve going to the intake and see if that is where the oil is being sucked in.

 

Valve seals sounds like a pretty good candidate..... Also, if your PCV is aftermarket, may wanna go to the dealer and get one.... They actually have the correct flow rate.

 

I have a mopar pcv thats only 3 months old in there. I'm thinking about pulling the valve covers and having someone crank the motor to see what happens. I pulled at the spark plugs and they look clean yet.

 

Do you have the air-gap intake? Or the hughes plate?

Might consider doing a compression check.

 

I have the air-gap. I am considering do the compression check as well. Doesn't seem low on power like low compression but you never know til you do it.

 

Well, its not a plenum problem then.

Do the compression test, and see what your numbers look like. Take it from there.

 

I would look into a bottle of at-205 before I thought about a costly repair like that. All it is is a reseal. It recondition the valve seals. It worked on mine

 

I have a bottle of AT-205 that I used on the power steering in my old grand prix. I think I should just do the seals and some 1.7 rockers as well, I may keep this truck for awhile unless I can find an off-road edition.............

 

So in a strange turn of events my truck quit smoking? I haven't done anything to it except put on 300 miles in 10 days. Now I'm totally lost, thinking about a compression test tomorrow.