Coolant low and changing color

[Nighsight]

I took my Powerboost in to the dealership because the coolant was low. I also let them know that the coolant was darker than normal and smelled different. They pressure tested the system and didn't find any leaks. I realized after picking it up that they didn't top up the coolant. I took it back immediately to have them top off the coolant (the foreman topped it off with Ford yellow coolant). It has been about 1500 miles and the coolant is below the minimum mark again.

When I talked to the Foreman about the coolant appearance and odor, he played it off like it was a mix of the old orange coolant and newer yellow coolant. I located a picture that I took during my first oil change and the coolant is definitely yellow. I am going to be taking the truck in to drop it off again this week.

Has anyone had coolant loss with no apparent external leak source (I have checked the exhaust heat exchanger, turbo feed pipes, EGR cooler)? I have about 37K on my truck right now. Is anyone close to that mileage that could post a picture of your coolant reservoir?

I am concerned that exhaust gases are somehow getting into the cooling system. My understanding is when that happens it can make the coolant more acidic and lead to corrosion in the cooling system.

Pictures attached for reference.

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[UGADawg96]

Paging @Snakebitten.....

 

[Snakebitten]

Paging @Snakebitten.....

I read it. But I've got nothing. At least not anything that I've got any historical reference with. (which is really all I do. I'm nothing more than another owner of these trucks, but with a huge appetite to gather and sort through documentation)

If there really isn't an external leak of coolant, which would be far more common with a Powerboost, then the coolant loss would be internal and never a good thing. Add to the discoloration, and you have 2 data points that imply coolant crossing an internal barrier. Again, not a good scenario.

I think the first thing I'd do is add some diagnostic dye to the coolant. It's either leaking externaly, but too stealthy to see without a visual aid, or it's crossing an internal barrier and being combusted, or contaminating another fluid. (theirs so many heat exchangers on a Powerboost. It's crazy)

By the way, the oil dipstick look OK?

 

[Gros Ventre]

I took my Powerboost in to the dealership because the coolant was low. I also let them know that the coolant was darker than normal and smelled different. They pressure tested the system and didn't find any leaks. I realized after picking it up that they didn't top up the coolant. I took it back immediately to have them top off the coolant (the foreman topped it off with Ford yellow coolant). It has been about 1500 miles and the coolant is below the minimum mark again.

When I talked to the Foreman about the coolant appearance and odor, he played it off like it was a mix of the old orange coolant and newer yellow coolant. I located a picture that I took during my first oil change and the coolant is definitely yellow. I am going to be taking the truck in to drop it off again this week.

Has anyone had coolant loss with no apparent external leak source (I have checked the exhaust heat exchanger, turbo feed pipes, EGR cooler)? I have about 37K on my truck right now. Is anyone close to that mileage that could post a picture of your coolant reservoir?

I am concerned that exhaust gases are somehow getting into the cooling system. My understanding is when that happens it can make the coolant more acidic and lead to corrosion in the cooling system.

Pictures attached for reference.

I've had a similar experience. I took a sample and had it analyzed chemically. There was no problem identified. I had specifically asked for a look see at exhaust gas in the coolant because of the color. Anyway at the end of the day there was no problem despite the coloration and seeming loss, although the loss rate was quite small and seems to have gone away... Here's the report from Blackstone Labs.

 

[Gros Ventre]

BTW the color, a slightly cloudy yellow-grayish (much like in your picture) is in contrast to the low temp circuit. That circuit has remained a bright yellow-green color, the color out of the jug..

 

[Mosey]

My coolant went down like that both times my exhaust heat exchanger leaked. As for the color, that is exactly what mine looks like.

 

[Snakebitten]

My coolant went down like that both times my exhaust heat exchanger leaked. As for the color, that is exactly what mine looks like.

I'd actually be thrilled for the gentleman if it turned out to be a slow leak from the exhaust heat exchanger tube(s).

And I guess it is possible that if the leak was slow enough, it might burn off before dripping?

$5 part!

Maybe get a white rag and reach up on top of the assembly and wipe around the tubes. If there's even a hint of coolant on the rag......
(also wipe down in the belly of the aluminum tray, where the coolant would pool and burn off before it could find an exit)

 

[rtf150]

Pic 1 during heat exchanger leak. Pic 2 where the tech filled it post repair. I topped it off and keeping an eye. I often think I’m still leaking and had another pressure test with no leak or pressure loss but I did lose coolant. It went somewhere?

You definitely have a color difference between your pic with the oil jug vs the close up.

 

[RcFlyer330]

yeah i have a similer issue with coolant loss it take about 6 months to go from max to min. i have looked everywhere expecially the heat exhanger and cant find any trace of a leak. there was one time over the summer that there was a spot on the driveway near the front of the vehicle that was coolant but it never showed up again. when I take the truck in for the 2 recalls it has i am going to have them check it out but with how slow the leak is i dont know if anything will be found.

 

[PB2021]

I had coolant drop when dealer did the underbody panel recall over a year ago. They had to remove some of the exhaust including the exchanger. Although it was returned to me at the full level I noticed it drop to about mid way over the next few drives. I had them top up at the next oil change. It’s stayed completely full since so I believe that was just a little air still in the system. I am experiencing the colour change in coolant though. Some have suggested it’s a normal colour change as it cycles and contacts various metals in the system but I’ve never seen that in any other vehicle and the other small bottle remains in like new colour bright yellow so I’m curious what is going on. Previous I was always led to believe the colour was an indication of coolant condition.

 

[AutonomousHybridF150]

My 21 PB with 70k had the coolant change colors. My coolant went down below the minimum slightly too over the life of the truck.

My brother’s 21 EB had the coolant go down below minimum some over his 70k miles. The color of his coolant matches mine exactly.

My PB coolant color turned at 20k miles.

No known leaks or issues observed on either truck/engine. My brother’s EB does have white residue on the original black up pipe connected to the throttle body/intake, which is directly behind the coolant reservoir and cap.

We talked about it last week when topping off his coolant. We felt like the reservoir or cap may have leaked during extended heavy towing. We weren’t sure if the white on the intake was the black paint changing colors or antifreeze spraying back on it over the past 2.5 years.

His EB was only 1/4 gallon low over 70,000 miles. My PB was the same after similar mileage. Ford service dumped out another 1/4 gallon when they changed my PB’s heat exchanger bypass valve a month ago, and returned my truck to me a half gallon low. I made the service department add the coolant back that they lost during the repair. lol.

I would assume it is not an issue.

 

[Snakebitten]

Thanks for sharing. Good to hear from the 70,000 mile club. There's not many of you so you own data points that aren't widely available.

I hope you get another 70,000 with no more fuss than the first. (even less would be better!)

 

[JIMFOUNTAIN]

21 Powerboost. 34K miles. Experiencing small coolant loss and the same discoloration. Seems to be a common "problem."

Seems like we all just watch it for now.

 

[HammaMan]

My coolant colors were the same for the first 4.5k, Now approaching 6k it's began to darken noticeably.

 

[PowerboostedF150]

Just noticed this the other day on mine. No noticeable leaks, smells, same as everyone else. Have the coolant below the min level. Dealer just replaced a pinion seal, no coolant issue to disconnect. My heat exchanger squeaks but doesn’t leak… I do need to check with a cloth though. 88k Km on this one.

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