white Residue around coolant cap

[westside98]

is it common to see white residue just below the coolant cap threads on the coolant fill/overflow res.? I just purchased a 2006 crew cab dually LB its got 146k everything seems immaculate (car fax and oasis) but i read a lil bit about coolant puking and a possible EGRC and or head gasket issue.

So i checked mine and noticed a little dried white residue near the outside of the coolant reservoir where the cap meets the threads any worry or some test i should run to see if I am soon to be in trouble. Also someone at some point added the green coolant mix should I flush and but the Premium gold or some other recommended brand.

[OVERKILL#1]

Have a pressure test done. My last 6.0 did the same thing and the head gaskets where on their way out.

[ZMANN]

caps and degas bottles are known to leak as well as HG issues

but best to have it checked and the procedure isn't like the old days with a hand held pump testing cap and bottle separate

[southend]

First, green coolant does not belong in your truck and generally speaking, it will not provide the protection from cavitation that your engine needs. Yes you should dump it out. Flush with tap and distilled water and replace with an ELC coolant with the CAT EC-1 rating. The revised coolant max level is now slightly below the min mark, any more than that and you will likely puke coolant. Coolant at the proper level, a new motorcraft cap, and a quick test of the coolant system is the route you need to take. You potentially have a busted egr cooler or bad head gaskets. You can google the test for 6.0 head gasket failure. You need a monitor to check your ect and eot deltas also. A monitor as ablolutely necessary when you own a 6.0. Read the stickies on monitoring. Keep us updated.

[westside98]

thanks everyone