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7.3 PowerStroke burns oil on decel

8K views 12 replies 6 participants last post by  ron68coug 
#1 ·
Valve stem seals? Valve seals?

I have never seen or heard of this happening before.

It really only burns oil after heavy deceleration. Or it seems to while decelerating and going around a turn.

It's a 2001 F350, 7.3 w/6 speed manual.

New IDM, 2 new pushrods (2 got bent in cold weather, never had an issue since I replaced them), 2 new alternators, new CPS, fuel filter changed approx 6000 kms ago. Straightpiped and K&N.

Also is running a Diablosport tuner on it, on the 100 HP setting.
 
#2 ·
What do you mean by burns oil? Smoke out the tail pipe? If so, what color and how heavy? How much oil are you burning in how many miles?

And last, but unfortunately not least, with that K&N, inspect the intake tube for any signs of dust or dirt. Then check the intake wheel for signs of dusting. Then check your blowby for any signs of pressure.

Here's to hoping that K&N didn't dust another engine. :beerchug:
 
#3 ·
I have the exact same thing (2001 F-350 6-speed), and mine started doing this recently, but only right after a cold startup. I'll back the truck out of the garage without using any go-pedal, then when I give it a bit to get out of the driveway I let off the pedal. It's right after I let off the pedal that a large puff of smoke comes out. I don't see it at all on acceleration, just when I let off......and only does this at first cold startup. After a mile or two down the road, I don't see it anymore. When it's real cold out the smoke is blueish white, when it's fairly warm out the smoke is darkish black. After a warm startup I don't see it at all......just that first cold startup every day.

Any ideas? I never see a drop in the level on the dipstick.
 
#4 ·
Sounds similar, but mine seems to do it worse once it is warmed up, leading me to believe it is the valve stem seals.

The smoke is blue, only shows up on decel and cold starts.

Maybe burns a quart every oil change, somewhere in there. But the blue smoke is really starting to annoy me, stinks and I'm sure the other drivers do not like it.

I clean the intake regularly, usually every oil change, there is never any dirt in there that I have noticed, and the turbo has no shaft play at all.
 
#5 ·
I have this problem right now. I have been towing my fifth wheel for the past few days and I started blowing white smoke, but only on deceleration. I have ran diags and nothing comes up. I did burn a little oil, but only about two or so quarts. I ran the buzz test, cylinder contribution and just a regular KOER diag. Nothing came up with it. I have not lost any other fluids, but my fuel mileage went down the tubes. I was thinking maybe I got some mixed fuel at one of the truck stops along the way and maybe got some dirt in the injectors. I also put in some diesel clean today, but have only gone through half a tank. Any suggestions?
 
#6 ·
Catch and release has nothing to worry about, that is the nature of our beasts when cold.
 
#7 ·
surftout... are you going through any coolant at all?
 
#8 ·
Shelby, does the smoke smell like burnt 15/40 or raw diesel? Try running without your tune and see if smoke goes away. If you bent push rods do to cold weather shut down, ditch the straight pipes! Just put something in there to keep the cold air from rushing up the pipe and f-ing up your valvetrain. On that note, if your pushrods got bent, you had some valve bendage. It may not be bad enough to run bad, but could have worn out seals on the damaged valves. I had this happen on my 68 390 coug with open headers in winter.
 
#9 ·
I found out what it was, it turned out to be the turbo. There was almost an inch of in/out shaft play, but you could only feel it if you gave the turbo compressor quite a little "tug" in and out. The side to side, there was absolutely zero play.

Got a new Van turbo on the way :)

I really doubt the valves had bent, the truck was running awesome and was even spooling the busted turbo no problem, no difference than before. I had one Powerstroke that had over 850,000 km's, and it bent a couple pushrods in cold weather once, replaced them, never happened again.

If the valves were bent, I would imagine they would have bent the pushrods again in the 300,000+ thousand kms the other truck saw, or the 15,000 this truck has seen since it bent the 2 pushrods.
 
#10 ·
Thank international for the mesh screens on the intake to keep turbo parts out of your valves. So how did your valves get bent, cold air?
 
#12 ·
Mesh screens??

where are these mesh screens located?
 
#11 ·
You mean pushrods?

I have no idea, perhaps cold air, I've fixed the block heater since then and never had a problem again after that.

The weird thing was, it was -40 degrees celsius out that night, so I was waking up and restarting the truck to let it idle every couple hours.

And the first truck that I had that bent the pushrods had a full exhaust system on it, so I am not sure if cold air contributed to that one at all or not.

Block heater works great though now :thup: and no problems since, tons of cold starts since then as well.
 
#13 ·
I thought they were under turbo, I could be thinking of a different engine, but am pretty sure I saw this at company shop when other mech. had his 7.3 torn apart, may be wrong.
 
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