I just came back from a 4000-mile RV trip. So I decided to replace the coolant, which was replaced last year and has only 5K miles. I have a Scangauge which shows typically about 15 deg delta between EOT and ECT while towing a 32-foot trailer (about 8000 lbs.) This delta would go up or down depending on going up or down hill. At times it could be around 20 deg while towing this trailer.

I have been draining the coolant from the radiator and replacing with 3.5 gallons of distilled water about 5 times now. I notice that the coolant has a milky white residue. When I look inside the recovery reservoir I see this white milky residue at the bottom once the coolant is drained out. I pour some distilled water in and everything is cleared out and the inside of the reservoir became clean again. The same thing happened again at the next cycle of flush.

My question is does diesel mixed in with gold coolant gives this white residue? I smell the recovery reservoir and thought that it smells a little diesel, but I am not sure.

After the 6th drain cycle I still see this white residue in the coolant. The Scangauge shows around 10 degrees delta or less without towing on flat road, 60-65 mph. EOT around 210, ECT around 200.

My last question is do you think I blew the head gasket(s) while towing this RV trailer but haven't blown them real bad yet, and everything seems to be working fine?

My truck is a 2005 PS F-250 with 155K miles, stock, no chips or tuning. Haven't had any issue so far. Thank you all for your feedback!

Towme

 

Two things.
It's not really an over flow tank is a degas tank/bottle. And if you have diesel
in the coolant that is coming from a problem with the head. It most likely is
a crack not a blown gasket. Someone will fill you in on how to check for this.
The way to fix it is replace the head. There may be some other way to test
for a crack with the head still installed but I don't know what the steps are
to do it. I do know that once the head is removed it can be pressure tested
on a flow bench.

Sean

 

If you have diesel in the coolant it is very obvious as the diesel is much darker in color and will float on top of the coolant in the degas bottle, with a blown head gasket a classic sign is white residue on top of the degas bottle from the system relieving pressure through the degas bottle cap and in some cases you will hear a sound akin to a tea kettle whistle under high load/boost conditions. Just make sure when you add coolant that you are not mixing coolants if it has Ford Gold in it top it off with Ford Gold and do not fill it above the low level mark that is molded into the degas bottle as this is the new high level and if you do you will likely puke coolant.

 

I don't know what the exact test is to determine if you have diesel fuel in your coolant or not. If you DO have diesel in your coolant it's ALMOST always from a cracked head (I actually don't know of any scenario where it's not a cracked head).

 

The one case where this may not be as obvious is if you are running a ELC that is red in color as it may be tougher to differentiate the stratification line in the degas due to the similar colors. I just saw this in my ex father- inlaws 04 6.0L, he was running the Ford Gold coolant and there was about an 1/8" of diesel floating on top of the coolant in the degas bottle. Three things were obvious, The degas cap was harder than hell to get off because the diesel caused the rubber seal on the cap to swell ( had to use channel locks to get it off ), the difference in color and the overwhelming smell of diesel once you got the degas cap off.

 

When my head was cracked, the mechanic was surprised that the cap wasn't difficult to get off. But the coolant definitely smelled like diesel fuel. I suppose my crack wasn't bad enough to fill the degas to the point where it affected the cap... Yet.

When the heads were pulled off, the mechanic said that he found signs that my head gaskets had also been seeping in all four corner cylinders. New heads with ARPs now.

 

Thank you, everyone, for your feedbacks.
First, there was no white residue coming out of the degas cap. It was all clean. I do hear a whistle sound while cruising, but thought that this is the normal turbo whistle.

It's very probable that I cracked one of the heads (or both) on this trip. The truck performed well and I did not push it too hard on the trip.

I use Ford Gold coolant and when I drained it from the radiator I thought that I smelled diesel. The drained fluid is initially yellow but has a white milky residue in it. The emptied bottom inside of the degas tank has this milky residue in it which feels oily, but flushed away clean when I poured distilled water over it.

It seems a little dissapointing that 6.0 heads are not very rugged. I wonder if it's common that 6.0 PS Diesel engines have a high rate of cracked heads. I believe I understand correctly that the blown head gasket is due to clogged oil cooler, which is a different issue. This engine is maintained well and not neglected (oil/filter changed every 5K miles or less.)

Since I live in the Phoenix area, I plan to take it to Bullet Proof Diesel and see what they say. If the heads are cracked, I wonder if it's worthwhile to switch the oil cooler to BPD and do upgrades such as ARP studs, STC fitting, etc. (that I read from this site) while they are at it? I will report the result. This will be one major and expensive repair!

Towme

 

Leaking head gaskets can come from a number of root causes:
1. Overheating
2. Excessive cylinder pressures (over boosting can be a cause, bad tunes can be also)
3. Hydrolocking from coolant
4. Hydroclocking from fuel
5. Improper torquing of bolts/studs
6. Poor surface prep on heads and deck
7. Improper parts (ie inferior head gaskets, etc)

 

Now that you've changed/flushed your coolant, drive it for a hundred miles or so and check the degas for smell of diesel again. If you smell it in there, you more than likely have a cracked head.

If changing head, while there do ARPs (w/ stock head gaskets), STC fitting upgrade, Dummy plugs, standpipes, oil cooler rebuild, EGR delete or BPD egr cooler, depending on your preference and your state's registration requirements.

Might as well do the blue spring upgrade too. Relatively inexpensive and seems to be recommended here, though this can be done at any time later too.

If you have the bucks you can go BPD oil cooler. That would have put me way outside of my budget, but if I had that kind of bucks....

Either way, if your head is cracked or just a head gasket, they've got to come off. Not sure if diesel would make milky coolant. It didn't with mine when I had diesel in the coolant. But I know that oil will make milky coolant.

Hey guys what about early signs of egr cooler letting go?

 

What does the engine oil look like?

Josh

 

Subcribing to this tread.

 

I had read about how much some people had to pay for repairing cracked heads and head gasket failures due to clogged oil cooler that I was doing all I could to prevent this from happening.
I believe that my oil cooler is more than likely OK due to the readings that I have had so far on my Scangauge. But cracked cylinder heads is something I am not sure how to prevent since I am not tuning or neglecting the maintenance. But I still need to see what the mechanic is going to say.
I have finished the 5th drain-and-fill cycle with distilled water in the degas tank. I noticed the milky water every time and the diesel smell in the degas tank. So it does look like your diagnostic is right that I have a cracked head or two.
I just checked the engine oil dipstick and the oil looks black. No hint of water there, and there seems to be no coolant loss so far. By the way, since the engine oil is black if it leaks into the coolant doesn't it make it black? Maybe the chemistry makes it milky white then?
I would love to do the BPD oil cooler, delete the EGR (no more EGR valve to deal with), and other suggested upgrades, and thank you for your suggestions. Too bad there is no Govnm't stimulus program for this! : )

 

Water in the coolant looks more like a chocolate milk shake.
What you may want to do is flush as if you had an oil cooler burst.
I don't have the data on how to do it. There is some type of soap
involved and more flushing. It really depends on how much more
work that would put into the job.

The info should be in the tech folder.

Sean

 

I think you meant OIL in the coolant

He needs to check the engine oil for contamination as well.

Josh

 

Thanks, Sean and Josh. BPD told me that the lead time to fix cracked heads or oil cooler is 6-weeks! I will drive down to their shop tomorrow so they could do a quick check on the smell of the degas bottle then decide what to do then get on the waiting list.
I haven't had any loss of coolant so I hope that coolant is not leaking into the oil! The oil dipstick does not show any watery substance but that's not a sure way to tell.