My 06 F450 has been running (kinda) great for awhile now. The last time I was griping here, it was running warm during the Texas summer heat. Still had a decent delta, but was cruising with EOT in the low 220s. Once the summer heat ended, it got down in the low teens, and now it's under 210. Always with deltas of 12-16, always while pulling about 10k lbs. Not sure why it can't handle the heat, but...

Before that, I had the debacle in Arkansas - stuck on the side of the road last Thanksgiving, ended up being a bad IPR valve. But, I tore down and replaced the STC too. Ever since then, it's made a strange fluttery, whirring noise at idle, almost like something is loose. I'm sure it's something I did wrong putting it back together. I have posts here describing it. It seems to run fine otherwise, and even seems like the noise has diminished somewhat, so I've kept driving.

About a month ago, I started getting the air filter warning message. Pulled the cleaner to replace and found oil on the underside of the snorkle and around the radiator and CAC tube right there. Seemed like an odd place for an oil leak. I don't see any leaks coming out of the block except the typical bell housing crud. I suspected oil sucked up the snorkle and that ruined the air filter. Now, that oil leak seems to be getting worse. I smell it when I get out of the truck.

Any guesses what I should be looking at? I'm wondering if instead of sucking in the snorkel, oil is coming down the air intake from the turbo, through the filter and out the snorkle. Maybe it's related to the fluttering noise - I've always suspected it was coming from the turbo, but since it seems to run fine, I thought maybe one of my other Marmon clamps was leaking (I replaced the one on the EGR that I mangled during that work). The area around bottom of the radiator on the driver's side is all wet, as is the bottom of the steering gear and steering linkage. Some oil blows on the tranny fluid tubes and runs on those all the way to the bell housing. I saw it dripping there when I changed oil.

Again, it seems to run fine, so I want to finish one more 600-mile trip I have booked this week before tearing into it. Will top off the oil before I leave, if it's low. It's not so bad that it drips when I park. It's got about 2000 miles since the last oil change, so I'll see how much it's lost when I check it in the morning. Doesn't seem to be a high pressure oil leak. Truck still starts fast and oil pressure gauge looks good.

 

It kinda sounds like it could be a crankcase breather issue. You could temporarily do the external crank vent to see if that's the issue, but like any temporary fix that works, it becomes permanent .

 

Using the starter trigger wire, does it crank even & smooth? Also when running, remove the oil fill cap. Is there alot of gaseous vapors puffing out? Is it enough that if you put the oil cap on upside down while it's running it blows the cap off?
The only other source down there would be if the bellows cracked on the plastic CAC tube.

 

that was one of my thoughts, but it could also be excessive CCV oil being sent backwards thru the air filter when letting off hard acceleration (when you get the fluttering noise).

 

I Agree, that's why I suggested he checks for excessive blow-by.

 

Ah I misread your first reply, we're on the same page! ("Only source" vs "only other source" mean 2 different things)

 

Thanks guys. I checked the oil fill tube the other day and it's fine, no blowback. And that fluttering noise is that Idol not while I'm accelerating it goes away as soon as I touch the pedal it off, again, like something's loose but it might be a turbo or exhaust leak is what I thought. I didn't notice the air filter being dirty on the turbo side like it was blowing oil out. It was dirty inside the snorkel in like it was sucking oil in. A break in the CAC tube seems very possible. Maybe the crankcase vent, I'll have to read up on it.

 

OK, finally got a look at this truck. The intercooler tube is cracked, right under the airfilter snorkle, right where all the oil saturation is. This truck has the one-piece plastic tube. Is it worth spending more for some "upgrade"? Maybe an 03 metal one from a junkyard? Is super-glueing the crack a temporary fix while I look for the replacement part, or do I just suck it up and order the factory replacement and be good for another 200k miles?

 

 

That would be awesome! I'll PM you.

 

How much pressure is in that tube? The crack is only about an inch long and becomes almost invisible when pressed together. Would some radiator repair gunk not hold it closed long enough to ship a replacement here - like a week and 1000 miles?

 

 

It's a boost leak on the pressure side, after the MAF, so it would cause an overfuel issue relative to decreased air charge; increased EGTs similar to lugging the engine would be a likely result. How bad I'm not sure, that's theory that I've never tested in person. If you haven't melted anything yet.......what's another week going to do to it?

I think it was Rusty maybe that tried to duct tape his when it cracked, pressure blew the adhesive and and made it whistle IIRC.

 

ok, the local dismantlers don't inventory CAC tubes, so they can't tell you if they have one and they don't show up in online searches. But, I lucked out. One place said he had a truck with the engine still in it, and I could come down and look for the tube. Turns out it was an '03, and I found the metal cold side tube in the back seat. But, the boots weren't with it.. However, there was an older 7.3 next to that truck, and the boots on it looked the same, and they were almost new. So, I took them, and they seem to be working. I have only driven my truck to the store and back, and I never romped on it to max out the Boost, but the boots stayed on. Total cost: $80.

Turns out there were cracks on the top and bottom on the original plastic tube. I was prolly loosing some boost and power, but I drive so slow, I didn't notice. It felt more peppy today, but I wasn't pulling a trailer.

Didn't fix the fluttering/vibration sound though.