Recently I purchased a 2008 6.4 with 90k on it. For the record I have had a few 7.3s and lastly a 6.0.... although... i wouldn't say i know too much about them .. especially the 6.4. I mostly used my trucks for leisure(pulling boat, SUV s.. etc.) Never really worked these trucks. I noticed a few days after i had this 6.4 L ... it seemed to have blow-by.... I could see it in the head lights at night while idling. I'm familiar with blow by and so forth... I own a small trucking(18wheels) business. As i was a little concerned... from what i know... this motor is covered up to 100k factory warranty.... its got 95k now... so... i'd like to get to the bottom of this if there is any reason to be concerned. I've read a little that some blow-by is normal with the 6.4 as it is with most any diesel engine. Although... i just can't make myself believe that it is normal the way mine is steaming. With all the lights off and shining a flash light through the engine compartment.. .. you can see steam/smoke coming all out. If you turn the headlights on with the hood down ... you can see it steaming out in front of the headlights. I have not noticed this in the daylight and don't think it is noticeable in the daylight. none of my other diesels done this and I'm wondering if i have anything to be concerned about. The steam/smoke... has no smell to it... i would think it would smell like oil , water, or something... but it doesn't smell like anything really... or my sinuses maybe just crap. This particular truck is a 08 f350 crew single wheel 4x4 with 6' suspention lift, 35 procomps... NO mods. short bed. Fuel mileage averages around 14 on the trip meter... thats all around. I've found it will get 16-19 running 55-62. Haven't noticed any changes in coolant level. No oil in the tube of the dipstick(as far as the blow-by)just steam/smoke like air coming out...not enough pressure you can feel any force if you put your finger over the hole. Oil on dipstick looks good. I will note that it is due for its first oil change since I've had it... so roughly... I've put about 5k on it. Boost seems fine... somewhere around 32 pounds(just roughly guessing by looking at the gauge when you get down on it). Coolant and oil pressure are always good. The coolant temp seems to run right below the middle mark. Anyways... May be nothing... but being able to see that steam/smoke while idling in the head lights kind of bothers me. So... if its normal ... i can deal with it ... but if its something malfunctioning .... I'd like to fix it..... so I guess i will leave my questioning at that and see where you guys go with it.... much thanks for your time

 

Kind of hard to pin down your issue here. It sounds to me like the tube that runs from the Oil fill spout that is suppose to go into the intake tubing is missing or off?

Otherwise you should not see anything. Is that tube missing?

Yes keep in mind this is a heavy boost motor. It is designed with that in mind so until the motor is work and heat is built up to expand the the rings for a tighter fit in the cylinders, there will be some blow-by.

Yes the motor has a 100K warranty. If you cannot locate the source of the blow-by other than what I have mentioned I would get it in and have it looked at.

 

Is it maybe an exhaust leak?

 

Well... I think i located the problem and possibly found another... wow.. my luck. Looked around engine very carefully and noticed that one of the boots that plug the hole in the valve cover for one of the wires that run to the glow plugs was out just enough that it was letting a "slight" oil dribble run down on top the exhaust manifold. I'm assuming that was the problem with the engine smoke/steam. Going to inspect it tonight after a evening drive. Even knowing it was there ... it was barely noticeable...It was a very slight dribble and with the oil so clean... it was almost clear. there's no traces of oil anywhere else... obviously because it was burning it off as fast as it barely dribbled out. Now what I'm wondering... is there any excess crank pressure causing that boot to slightly push out like that. Went to the dealer today. I have a buddy that manages service department.... problem is... They never keep good diesel service techs. He'll help me out with computer stuff without charge most times...So then ... come to find out... we were going to do a extended warranty... and it comes back that the truck had a canceled warranty back at 36k... because the guy that owned it .. made the mistake of putting gas in it and ford wanted to replace this and that.. and the guy refused. From the sound of it.... I think the guy put gas in it and realized it then... and didn't want to tare his truck apart. But who knows... my buddy said he must have fixed it obviously... because that was 60k ago and the truck seems to be in great shape... they put the computer on it and everything ran A+ ... no codes. He said they could check crank pressure but i'd have to leave it with him tomorrow. I was thinking i would save myself the hour labor for checking the crank case pressure and so forth ... The computer is mostly free for me... door codes.. engine codes.. stuff like that.. because i bought a decent amount of vehicles over the years (ebay, out of state, etc..) and gave them the work if i ever had anything wrong. But I'm going to have to pay them something if i keep checking this and that. I think I'm going to drive it and see if it kicks that boot back out again and that may definitely tell me if i have a case pressure problem . That's what AKA Senior Master Technician said to do. Any feed back or just common talk about this thread or 6.4 in general are welcome... thanks

 

As long as you have the tube onto the oil fill spout and it is not plugged then you should vent just fine.

 

After finding that one of the rubber boots housing the wiring that runs to one of the glow plugs in the top of the valve cover was very slightly popped out... letting a very small dribble of oil run on top of the manifold.... I reached in with a thick flat head screw driver and pushed it back in. I ran the truck all day today.... I wouldn't say i abused it.. . but deffinently ran it like i stole it. I wanted to see if i had enough excess crank case pressure to push it back out. Later tonight after getting it good and warm at operating temperature... I check around the truck and the engine compartment for any of the smoke/steam like effect it was making and I haven't found any more signs of it. After all the driving today... The rubber boot is still in place. So... i think i feel confident about it and I'm going to continue to drive it without going back to the dealer for further testing at the moment. Next I'm going to test it pulling my 28 ft Baja go fast boat for a trip and see how it does then.