I normally work on 7.3s and 6.0s. My brother's company just bought him a 2008 F550 service truck with the 6.4. As far as I can tell, it has either a bad EGR cooler or a bad head gasket; it's consuming coolant and he tells me there was a white exhaust cloud under heavy throttle. Test for combustion gas in the cooling system was positive.

Anyhow, to make a long story short, his boss is insisting they drive the truck to get the crane on it certified before fixing the coolant loss issue. It's currently low enough on coolant that it threw a coolant flow code and went into reduced power mode. Is there a special fill/bleed procedure for the 6.4 so I can at least tell him how to get coolant back in and try to avoid any heat related damage? These engines don't have 2 separate cooling systems like the 6.7s do they?

 

If his boss says to drive it, I wouldn't do a damn thing to it but drive it till it locks up or blows up. When they replace the motor after it blows up, that should solve the issues.

As for filling it up, just add water till she's full. Yes, it has a 2nd cooling system for the High Pressure Fuel System, but that is completely separate from the engine coolant system.

The 6.4 is a much different motor than the 6.0's and 7.3's. When you see smoke from the exhaust, you need to pull over and get it towed to a shop and get it fixed. The main killer is if an injector stays open and washes out a cylinder. Head gaskets, I'm not so sure about. I know it costs a lot more than a 6.0 to fix, but I don't know how much. Also, I don't know if driving it with a blown HG will do more damage to it real quick. I know a 6.0 you can sometimes drive it for a while before fixing it. I would think that with the 6.4 and the emissions stuff on it, that the blown HG might do more damage to it quicker than the 6.0.

 

Sounds like a smoked head gasket Pic. Oil still look good?? If so motorcraft gold antifreeze fill up and monitor. (additive for the antifreeze as well). Like our 7.3's these 6.4s will pull a hogged out cylinder a long way. They are beasts. Just have to figure in that every plunge on that cylinder is racking up cash.

Can you smell antifreeze from the exhaust? At what rate is it using, and did you pop the fuel cooler to see if it was running dry. (fuel cooler looks like a brake reservoir) I fill mine periodically and it doesn't stay full. Don't know where it's going but it is common maint for me.

Denny

 

http://www.powerstrokediesel.com/doc...Table_Book.pdf

This link will help you troubleshoot the problem and quite a few more.

And, i also have the entire 2008 F-250, 350, 450, and 550 repair manual saved to my computer as a pdf. If, you know how i can send it to you, i will. The entire manual is to big to send in an email but, it is broke down into a bunch of pdf's. I actually just downloaded it last night after stumbling across it. I am definitely glad that i found it. The information it holds is priceless.

 

Best Christmas present ever, Thank you so much for doing this!!!

Denny

Sending reps bro!!!