94 7.3L Blows blue smoke when letting off the gas????

[LItrailers]

Hey Guys

I was just coming back from a quading trip and I noticed that when I let off the gas I see a puff of blue smoke from the exhaust, motors seems to be running fine nothing different any ideas??????

Thanks Chris

[gabelnj]

free

[jamstoyz]

my 02 is doing the same thing but alot of smoke and its blueish white color. was told its either a bad injector or bad seals in the turbo. another person told me the motor is shot. rings going on it. whats the mileage on your truck?

[LItrailers]

I only got 164,000

I thought of that but I really dont think the motor is going, I am religous with oil changes.

[totalloser]

I would say one of two things; Valve seals or sticky rings. Valve seals pretty typically do this in gassers. Dunno what they look like in a 7.3 IDI. The other thing is stuck rings. Carbon builds up in the ring grooves and plugs the little ports that go to the oil control rings. Sometimes they'll get stuck just from sitting in the same spot enough, but if you heat up the engine a little or rev it high, the pistons warm up just a little more (aluminum expands more than iron) and pushes the rings into the ring grooves sticking them in the carbon.

The fix for the rings is to do a motor flush. Follow the instructions carefully, if you load up the engine with solvent in the case, you'll be buying a new one. But it cleans all the oil ports out really well, and very frequently unsticks the rings. Expect oil pressure to rise slightly, too. I do this about every 100k if nothing else but to keep the oil flowing through the rods and pistons. After doing teardowns after a flush, I do a flush before tearing ANY engine down.

As to valve seals, they can be done in place but it's a pain. I'd just burn the oil, personally. But you can TDC firing each piston and pull the rockers, spring and keepers and slip a new one on each valve. Just make SURE your piston is TDC, or you can drop a valve!

[brian norwood]

whats is a good flush?

Thanks

[totalloser]

I use the napa fast flush stuff lately, but I think I used to use stuff called Engine Restore. I don't think it really matters which you use. Old timers used to run diesel in the crank case to accomplish the same thing, but I would buy the stuff in the can-it probably works better, and maybe safer.

My suggestion is to ignore the label's recommendation to do it every other oil change. It is a solvent, and probably not too nice to seals. Besides, it is not needed more than about 100k or so, as the deposits take time to form.

And again; NO LOAD ON THE ENGINE with that stuff in the case. It's solvent, and cuts the viscosity of the oil. It is entirely possible to scatter your bottom end if you take a drive with that stuff in the case. Follow the instructions.

[lifewitlooie]

I remember someone saying blue smoke it oil burning