I noticed about 1 year ago I had diesel in my coolant but wasn't sure..
took it to a Ford Guy about 45 minute's away.. He seems to know his stuff but when he tested the coolant the results said less than 2% diesel.. But he did find an injector issue and swapped it out..
Foward to present.. there is diesel in my coolant now , since the level is rising to almost overflow and I beleive this has been doing on for quite some time as I have that smell you get in the cab..

BTW - All injector cups have been done about 3 Years ago..

On another note , I get white smoke on start up especially if the truck has sat for a day or 2..

What can cause diesel in the coolant..

I did a complete coolant flush this summer and was super **** about getting all the old coolant and gunk out.. Ended up with only clear water coming out the degas

Kyle

 

What can cause diesel in the coolant.... Injector Cups. That is the only time when diesel and coolant are close enough to each other in the motor as coolant flows through passages in the heads to cool the injectors and cups.

I had this issue over the summer. Since the coolant flows through the heating hoses and radiator hoses, the diesel can be a major problem. Diesel will destroy the rubber hoses so you will need to check them all.

Get this fixed asap, if you are about to overflow, the issue is serious and will be easy to find the injectors out of the head. Sorry but this is not ok and shouldn't have been allowed to go for so long.

This is an issue that could be found after a 200 mile drive. If it's been going for years, you repair bill might be high with replacing the heater hoses and radiator hoses. Just want you to prepare...

Here is a pic of mine after 200 miles. I turned off the truck and had all the cups replaced. 5000 miles later, no more issues.

 

Thanks for your input..
The leak must be very small.. crack in a cup maybe..
Since I flushed it this summer and have put on many miles since..
I have been running off road diesel so the color is not night and day.. like clear diesel..

Kyle

 

Mine has sticky dark coloured stuff in it.

 

Sounds like this could be a bad O-Ring injector..
and not a leaking or cracked cup after all.. Maybe why this has been an ongoing leak and could also explain the white smoke..

I'll know soon either way

Kyle

 

It's an easier job for just O-Rings, but if you have that much diesel going through the hoses, you'll. still need to check and replace as needed.

 

If you really have diesel fuel in the coolant degas bottle, I will be very surprised if none of your cups are cracked or if you don't have a compromised seal around the cup(s).

 

Could the fuel not pass at the injector o-ring if the injector is lifted ?
Or would that in itself cause a cup to lift ?

Kyle

 

The orings only hold back the oil and fuel the injector cup holds back the coolant.

 

The injector cup (physical, metal barrier sealed with a form of Loctite) separates the coolant from the fuel inside the head. The O-rings on the injector separate the oil from the fuel.

O-ring failure on the injector would more than likely result in oil in the fuel and would be witnessed by a black fuel filter due to ICP (post HPOP oil pressure in the head) being at up to 2800PSI (stock) and fuel pressure usually being less than 65PSI.

 

As mentioned before - a failed O-ring can't put fuel in the coolant. The fuel exists in just one place, once it leaves the fuel lines - it goes to the fuel rails deep inside the heads and nowhere near the head gasket. The pressurized fuel is on one side of the cup, as well as over the lip of the cup. If the seal on the lip leaks, or the cup is cracked - 60 PSI fuel vs 14 PSI coolant means fuel in coolant.

Fuel in coolant has one solution - replacing one or more cups. Sorry.

 

So how can you figure out whether its fuel or oil in the coolant?
I got similar problems.......

 

Oil in the coolant or degas bottle will look milky exactly like ExPaCamper has stated in your thread. Diesel will not look like that, but will have a light golden color in the degas bottle. Be glad you have oil and not fuel. Your oil cooler repair is much simpler and can be done in a couple of hours and is less expensive as opposed to cups which will take two days due to set-up time for the Loctite.

 

2 days {chuckle}. Unless you're as inept as I am, then it takes 2 weeks.

Actually... I had other issues with the truck that led to the cup damage, and it took me a while to sort that out while I was doing cups.

 

Mine doesn't look milky that's my point .................