Long story. 2007 F350 6.0L. 300.000+ miles on it. At just after 100,000 miles, lost head gasket. Fixed at dealer and better studs put in, After that we have done the following mods: EGR delete, Bullet proof oil cooler, water pump about 2 yrs ago. This year, all new hoses and fan clutch, Mishimoto aluminum radiator, degas and thermostat. The new thermostat went bad and engine running very cool. Mishimoto thermostat on back order, so they put OEM on until it came in and were going to change it out at next oil change. However, when it was in for the temporary thermostat, shop says he noticed signs of fluid out the degas bottle and that we have a blown head gasket. Quote is $5K to replace head gasket and, due to age of truck, new OEM heads recommended. The heads are $2K and labor $2K plus misc....

So, trying to stay objective, but the truck runs fine and there is no further sign of fluid out the degas. Degas fluid level is about 1/2 way between min/max. Fluid level did rise slightly when engine cool and cap taken off. Is fluid out the degas ALWAYS a bad head gasket??

Thanks!

 

The fluid will always rise and fall when the cap is removed from a hot system under pressure.

Coolant leaking out the cap can be other things than a blown head gasket:
1. Weak cap
2. Bad sealing surface under the cap (uneven, gouge, etc). You can inspect this yourself
3. Crack in the bottle. You should fill it w/ air pressure (15 psig) and see if it holds pressure, but it will take rigging up the hoses and the gauge.
4. Overfilled system (liquid will expand when heated up and a small vapor space will over-pressure). The cold level needs to be just above the minimum - say 1/2".
5. Coolant mix is weak (ie much less than 50% glycol). You can get a cheap tester at any auto parts store.
6. Excessively high coolant temps could also cause leakage from the cap. Doesn't sound like this is an issue for you.
7. Your EGR delete may have failed (depending on how the EGR cooler was deleted). Tracking this down is again specific on the kind of delete.

Did the dealership even suggest trying a new cap?

btw - the heads originally were held on with bolts. The upgrade is to go to studs. While there are different manufacturers of studs, the overwhelming choice is ARP brand studs.

I would bet you got the same old head bolts. Some dealerships will, but most dealerships won't switch to studs, they are considered a modification. It is an internet myth that there EVER WERE upgraded bolts.

 

Thanks. I will look into the degas bottle cap and other things you mentioned. I have been thinking that could be the culprit since it is new. We have spent so much money on mods to prevent the head gasket blowing again! We are working with a local shop and pretty happy with the work there the last few years.

The Ford dealer did do the original head gasket repair. They did recommend studs and I paid $500 extra for them so I hope they put them in. I assume you can tell the difference looking at them....

I have also read about a pressure test that can be done under load. Is this a definitive test for HG?

 

For the coolant system pressure test to be valid, you need to start w/ a leak free system. So you need to track down the first three items on the list above.

The next 4 items in the list above (I added one in a late edit) can generate excessive pressure, so you need to track them down.

Then you can do the coolant system pressure test and, if you develop excessive pressure that quickly returns after venting the system, you can be pretty confident it is head gasket.

Sounds like you did get studs then. Do an internet search for 6.0L head studs picture. You will find pictures that show you how to tell.

 

Pretty easy to spot studs - they have nuts on them versus the head of a bolt. You maybe able to do the cheapo test using the rubber stopper in the degas bottle and rubber hose going into a clear jug of water. If there's bubbles, you either have gaskets or a blown EGR, and since you don't have an EGR, it would be gaskets. But not sure that works without the EGR. The link to a vid from BPD showing how to do it is around this forum in a few posts.

 

Some dealers were always open to doing studs if the repair was done post warranty or at the end of warranty so they didn’t go against the warranty charge-back God’s. I would guess that with Ford selling studded reman motors as an option, more dealers would be open. It would be interesting to see if those studs are ARPs or someone else’s in the long blocks. There’s no reason for them to be ARPs, and the profit margin would be huge to offer studs that cost much less. In the used car market anything but a studded motor post repairs has no advantage in sales.