Degas Cap leaking on low mileage 6.0!
 

I have researched and read most of the issues with this symptom. Here's my particulars. 2006 F250 6.0 40,000 miles and I have had it since new. Almost every time I tow with (once or twice a year) it I will get the white residue around the cap. When it was under warranty I took it to the shop to have it looked at. The last time two years ago they replaced the oil cooler and I finally towed with it last week and the same result occurred As i have stated I just don't tow with it that much. Recently I got the Low boost and low ficm voltage dtc's and I removed and cleaned the turbo and replaced the Ficm half shell. The truck runs like new and should hardly be broke in but this issue has been there since new. Like I mentioned I just don't tow enough to have discovered this when it was still under warranty. My thought is HG's but how can they be bad with so little miles and really no hard use? My next one is bad cap but i would think The local shop would have checked that the last few times in when they told me they couldnt find anything wrong. Any suggestions would be greatly appreciated.


By the way this thing is bone stock.

Definitely try a new cap - very cheap thing to try.

I have a pressure gauge that I monitor the degas bottle pressure with. Installing one of those would be the most helpful thing you could do to troubleshoot it.

Ditto on the new cap ... there was a design update.

I replaced mine and it solved my degas leak.

Install a "fuel" pressure gauge with a reset -like a tire air pressure gauge.

Unhook the 3/8" line insert tee with gauge and a small piece of hose back to tank.

gauge should read no more than 30 psi so you get a real good reading, 20 is about as low as you want.

you'll know real quick if its head gaskets, truck should run 4 - 7 psi no more than 10 and anything above 15 is really bad.

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Thanks guys. I will definitely look into the new cap. Is it recommended to get another OEM or aftermarket cap. I will see if the local shop has a gauge to test the system.

Well it looks like head gaskets. I t'd in a pressure gauge and ran it up the nearest mountain road. The gauge read normal (4-5 psi) until the boost got over 20 psi then it climbed up to 16 and the cap would release the pressure. So it looks like I will have to spend some money. Crap!!!