I had the well known intercooler hose blow off this past summer and while I strugggled to get it back on, which I did, I wondered why there was oil all over the underside of the hose. I have been checking it ever since, and wiping it off but there always seems to be a bit of oil on the rubber fiitting and clamps. where does this come from...should it be a concern...my oil level is always fine.

 

The oil gets in there when the engine is under heavy load. It's a quirk of the Crankcase Ventillation system.

What happens is that under a heavy load, as with all engines, pressure builds in the crankcase of the engine. The excess pressure is vented through a tube. Years ago, they just vented it to the atmosphere, but because of emissions concerns, they now send in into the air intake and have the engine burn the vapors.

Since the engine is turbocharged, the only place you can have consistent vacuum is on the intake side of the turbo, so that's where that hose goes in.

When it's under heavy load, the flow out that ventillation line is greater, so it catches a bit more oil and oil vapor than it usually would. Since you've got a load on it, the turbo is also spooled up higher, which means you have even MORE suction to draw the vapors in, too. So, a little oil gets in there and is pushed into the intercooler lines by the turbo.

Is it really a problem? Not usually. I've seen it happen with engines in other applications, too (Big Rigs and Tractors). Diesel Engines are under a lot more pressure than gas engines are, and the turbo effectively makes this pressure higher. You can reroute the CCV line and get rid of the problem, but that is in violation of the EPA rules and what-not. Some folks have done it. The threads will turn up on a search. I just clean my engine every six months (a clean engine is a happy engine, and also an efficient one) and don't sweat it.

 

I have an interesting question about the oil in the intercooler, after time won't the oil clog and plug the tubes? How come ford has not added a oil seperator into the line? i work with refrig equipment and all our line going to coils have oil seperators on them to keep them from pluging up, and they run in the minus temps.. At ambient temp i sure all of you have had a oil leak on your bench, shelf and found a sticky mess from a oil leak of some sort. Think what goes on in the intercooler after time, this can reduce the airflow and hamper performance. I did a search for oil seperators for pvc systems and found this:http://www.c-speedracing.com/howto/c...n/catchcan.php
It might be worth checking out for some who have concerns about oil in the intake system.

Smokeploe
06-F250 XL STRAIGHT STOCK
AND LOVING IT ALL THE WAY

 

I had my tube blow off this summer as well, The clamp actually broke, the dealer I got the new clamp at suggested removing the hoses every six months, cleaning the hoses up and reinstalling and retorque the clamps to help prevent them from slipping off. (it would not have helped in my case, check out my gallery)