08 coolant leaking - dealer can't find

ssmiths · Jul 16, 2015

Been through a lot of pain lately trying to find the reason for a continuing coolant leak. Usually shows when towing my fifth wheel. Lost 6 quarts in about 130 miles, twice, all in a trip camping and back. Recently had egr valve and housing replaced, followed a month later by 3 coolant hoses, and then both egr coolers. Way too much money, especially to continue having problems. Took it back to the dealer for this latest problmem. They pressure tested and can't find a leak. Next is to hook up my trailer and tow that down to them so they can test it under load. I can smell antifreeze, but don't see a leak. Oil looks good. Any suggestions on where else to look?

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Stroked777 · Jul 17, 2015

If you can't see a leak them most likely it's going into the engine via egr cooler or head gaskets. What's your oil level and oil look like

Powerstroke Man 6.4 · Jul 17, 2015

ssmiths said:
Been through a lot of pain lately trying to find the reason for a continuing coolant leak. Usually shows when towing my fifth wheel. Lost 6 quarts in about 130 miles, twice, all in a trip camping and back. Recently had egr valve and housing replaced, followed a month later by 3 coolant hoses, and then both egr coolers. Way too much money, especially to continue having problems. Took it back to the dealer for this latest problmem. They pressure tested and can't find a leak. Next is to hook up my trailer and tow that down to them so they can test it under load. I can smell antifreeze, but don't see a leak. Oil looks good. Any suggestions on where else to look?

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If you have the old style white label degas bottle cap, replace it with the new all black style cap ASAP.

Is the truck puking coolant out of the degas bottle? how does the coolant look color,level,smell? look at your driver side end tank bottom and top on the rad is it leaking? ECT/EOT look alright? any white smoke? Oil level and color?

78f100 · Jul 17, 2015

Look at your oil, if it's feels really thick it's going in your crank case through the front cover. I recently put a engine in a 450 that had been to the dealer 4 times for a leak they couldn't find. It was the front cover. By the time he got it to me the bearings were bad.
Get a pressure tester, put it to 16psi and let it sit, if you can't find it leaking externally drop the oil. Let it sit with the oil completely drained and the pressure tester on. If you start seeing drops of coolant out the oil plug it's the cover. A tiny hole in the cover will take a while until coolant starts dripping out the pan.

ssmiths · Jul 17, 2015

Thanks for good responses. I have the black degas cover, oil level, color, and consistency look good. Coolant level drops dramatically while towing - about six quarts in 150 miles. No exhaust smell in it, puked out a couple of times, but not as bad as before the egr coolers were replaced. Radiator is dry. I don't have oil temp, but tranny and coolant temps have stayed in the middle of the range always - no obvious overheating. I will mention the front cover possibility to the dealer next week.

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78f100 · Jul 17, 2015

If the front cover is leaking bad sometimes you will see jelly like oil and water mixed on the bottom of the oil cap.

Dzchey21 · Jul 17, 2015

what color is your truck?

If its a darker color you will be able to see that the coolant has come from the degas bottle and sprayed on the bottom side of the hood. Is there a white film or spots near the degas bottle or on the bottom side of the hood?

Sounds to me like an external leak that is evaporating before it can be seen, it also sounds to me like the cooling system is under higher pressure than it should be while towing and most likely needs head gaskets.

EGR coolers are another place to look, but if they replaced them then who knows. One thing to try on the intake is to pull the intake horn off and look down in the intake. If the intake looks clean then I bet its the EGR coolers. The hot coolant will steam clean the intake out.

I agree with others too, pull the oil fill cap and post a picture, we can tell just by looking at it.

ssmiths · Jul 19, 2015

My truck is black, so I can easily see blow out. Looks pretty clean now, mostly residual from previous events when the coolers failed. I did have some puking from my last tow a week ago. Pulled my oil cap, it's clean and fairly dry, no indications of anything in the oil. I am thinking it may be a localized overheating, causing antifreeze to steam out, but only when towing. Maybe oil cooler plugged, starving the erg coolers of coolant? Next week I haul my fifth wheel to the dealer and they will instrument everything and monitor while I tow -fingers crossed we will find the problem.

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ssmiths · Jul 21, 2015

Dealer checked today. Exhaust bubbling into degas tank. Either erg coolers again or head gasket. They say they have not had any hg's on the 6.4, but say the cab has to be removed to do the work. Sounds expensive. They are checking with Ford for help - warranty? Truck is an 08 with 88 k miles, so fingers crossed!

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Stroked777 · Jul 29, 2015

Get coolers can be removed cab on. Just gotta remove the radiator I believe, that's if you wanna tackle it yourself, a dealer will lift the cab to make it easier