06 F350 P1140 Coolant Vapor In Fuel??

ETS · January 12, 2012

I have a head scratcher, 06 F350 6.0, 4x4, 70k miles. Came in with complaint of water in fuel display on cluster. Customer has added additive through last 2 tanks and switched brands of fuel. Took fuel sample looks good. tested pressure good. Small amount of sediment/deposits on old sensor. Replaced sensor, filters with updated kit [according to dealer] and shipped it. Came back this week same code, Warning appears after a long run almost every time now. Was running it with scanner and noticed heater goes cold at idle. Customer had not noticed this. No pressure in degas bottle or loss of coolant noticed. Could combustion gas/coolant be triggering this on the return side?? Runs good, no issues with driveability. I am going to get it in and try fuel sample from return with running engine and check color/bubbles etc. Has anyone seen a problem like this? Any opinions will be appriciated.

ETS · January 16, 2012

I went through several heat cycles this weekend with pressure on cooling system. Drained pump module and found about an ounce antifreeze in bottom of 1 quart fuel sample. Next is try to determine which cylinder & injector cup or head gasket. This is first one I have seen like this. No contribution codes or drivability issues at all. Going to pull valve covers and injectors for close inspection. Any opinions would be appriciated.

Bruce Amacker · January 17, 2012

Assuming it's still operational, I'd put a bunch of UV dye in the coolant and secondary FF (they're different colors) and run it a bit to mix it in. I'd then pull the injectors out and use air to blow dry the injector bores. Next I'd cycle the key a few times and use a UV light to hopefully see some leakage or seepage from the sleeves along with pressurizing the cooling system to 20ish. Hopefully something will show up by here but if not I might pull the fuel check valves from the front of the heads and install an adapter to allow air to be applied there. IIRC, the thread is 12x1.5, the same as a FP check fitting.

Keep us posted. 50% of the time this is cups, and 50% of the time it's a cracked head. I'm assuming this is CP and not extended warranty. After you find your problem don't forget to drop and clean the tank. Maybe I'm having a brain fart, but I can't see a head gasket causing this on a 6.0.

Good Luck.

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ETS · January 17, 2012

Thanks Mr. Amacker,

Loosing heat at idle had me thinking head sealing issue. But you are correct, No way to get coolant into fuel there. Posted Image

I will get some UV dye and try to finish diag this weekend.

Truck is still together, Parked it for now to prevent further damage.

This is fellow employee's personal truck. there is no warranty left already been there. His time and funds are limited, Talking about trading it back to dealer where it came from. It's been a bit of a lemmon the whole time he's owned it.

Please send me your E mail, want to invest in some advanced training!

Bruce Amacker · January 18, 2012

My contact info is right on my website linked below, bamacker@aol.com, 440-846-3885. Materials can be ordered by phone or on the website and paid by CC or PayPal.

Good Luck, and let us know what you find!

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GregH · January 20, 2012

I'd then pull the injectors out and use air to blow dry the injector bores. Next I'd cycle the key a few times and use a UV light to hopefully see some leakage or seepage from the sleeves along with pressurizing the cooling system to 20ish.

Wouldn't cycling the key with the injectors out dump fuel all over the front cylinders?

Bruce Amacker · January 20, 2012

Oops, my bad. Yes, it would.

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ETS · January 20, 2012

I am going to finish Diag. Sat.

2nd test, because air in lines may spoil results.

The only way I can think for finding leak is removing fuel lines from front of heads and pressurizing cooling system. [With injectors still installed] This will tell me which side. This test will have to sit overnight to see results. It is very slow leak.

1st test,

Thought glow plugs may tell me which cylinder. [Discoloration] But truck does not smoke. Thought about using air in cylinders 1 at a time also and look for bubbles in fuel filter housing and coolant.

Will pull and inspect injectors & cups last.

Any more ideas without pulling head?? I will have to pull head-s at some point. But can't tie up my bay yet. I am leaning more toward cracked head on this one.

If Mr. Browning still has cab removal write up for 06 it will be greatly appriciated. Going to use overhead crane to lift cab on this one. E Mail is sales@elkinstruck.com

ETS · February 5, 2012

Update on Diag. for anyone that is interested, First thanks to Mr. Clayton for the cab off diagrams. Cylinder air tests were negative for bubbles in coolant or fuel. No abnormal coloring on glow plugs to give away which cylinder. Removed fuel check valves at front of heads pressurized cooling system overnight. Found couple of drops of coolant at right head. Why is it always the right side? Especially #7 & #8? It seems the colder it is the more coolant it uses. If I keep it plugged in usage almost stops. Have had no more water in fuel warnings since last filter & draining. Both heads are comming off to be pressure tested. Thanks for the tip on pressure testing with soapy water, [tricks for 6.0] Will defonately try that.