2015 Expedition 3.5 EcoBoost – slow coolant leak at driver-side turbo, looking for input

H60John · Jun 3, 2026

Hey all, wanted to lay out my situation and see if it lines up with what others have experienced.

Truck: 2015 Expedition Platinum, 3.5 EcoBoost, ~121k miles.

Background: Bought it ~7 weeks ago. Had a timing cover reseal / rear main / oil return pipe done right after purchase (warranty work). An oil drip showed up the day that job finished but has since resolved – no more oil.

Current issue: Now I've got a COOLANT leak (orange Motorcraft, bitter/watery) weeping at the driver-side turbo area. Symptoms:
- Only shows up after the truck is warm / driven, dries up overnight
- Drips a small contained spot on the driveway (~fist-size an hour after a drive), not a puddle or trail
- Coolant reservoir is holding steady
- NOT overheating, temp gauge normal
- Visible orange staining + a fresh droplet at the fitting near the turbo

Diagnosis so far: Dealer says left turbo internal seal, $1,833 to replace the turbo. Christian Brothers quoted $1,775 (Ford reman turbo, ~$700 labor) but that was off the dealer's diagnosis, not their own look. I have NOT confirmed whether it's actually the internal seal vs. the external coolant line/jiffy fitting/O-ring – from what I'm reading those clip-in fittings are the usual culprit and a much cheaper fix.

My plan (can't afford the repair right now, looking at ~a year out):
- Monitor reservoir level (check cold) + watch temp gauge
- Keep a jug of coolant in the truck, top off as needed
- Avoid long hauls / towing where I can (typical drive is ~90 min)
- Pay for a cooling-system pressure test ($80) to confirm seal vs. line before committing to any repair
- Possibly upgrade to AN/braided lines when I do fix it so I'm not chasing it again

Questions for those who've been here:
1. Does a slow weep like this realistically hold for months on careful monitoring, or did yours accelerate fast?
2. Anyone have it diagnosed as "internal seal / replace turbo" when it turned out to just be the external fitting/line?
3. For ~90-min highway drives, anything beyond "full before you leave + watch the gauge + carry coolant" you'd recommend?

Thanks in advance – trying to nurse it safely until I can afford to do it right.

17expi · Jun 3, 2026

I agree with your "plan" except for the $80 coolant check, which won't tell you anything you don't already know, and braided lines won't do anything other than make your wallet lighter. It's probably one of those little O rings in one of those tubes that you can fix yourself. Pretty common leak and nothing to worry about.

99WhiteC5Coupe · Thursday at 6:21 AM

H60John said:
Hey all, wanted to lay out my situation and see if it lines up with what others have experienced.

Truck: 2015 Expedition Platinum, 3.5 EcoBoost, ~121k miles.

Background: Bought it ~7 weeks ago. Had a timing cover reseal / rear main / oil return pipe done right after purchase (warranty work). An oil drip showed up the day that job finished but has since resolved – no more oil.

Current issue: Now I've got a COOLANT leak (orange Motorcraft, bitter/watery) weeping at the driver-side turbo area. Symptoms:
- Only shows up after the truck is warm / driven, dries up overnight
- Drips a small contained spot on the driveway (~fist-size an hour after a drive), not a puddle or trail
- Coolant reservoir is holding steady
- NOT overheating, temp gauge normal
- Visible orange staining + a fresh droplet at the fitting near the turbo

Diagnosis so far: Dealer says left turbo internal seal, $1,833 to replace the turbo. Christian Brothers quoted $1,775 (Ford reman turbo, ~$700 labor) but that was off the dealer's diagnosis, not their own look. I have NOT confirmed whether it's actually the internal seal vs. the external coolant line/jiffy fitting/O-ring – from what I'm reading those clip-in fittings are the usual culprit and a much cheaper fix.

My plan (can't afford the repair right now, looking at ~a year out):
- Monitor reservoir level (check cold) + watch temp gauge
- Keep a jug of coolant in the truck, top off as needed
- Avoid long hauls / towing where I can (typical drive is ~90 min)
- Pay for a cooling-system pressure test ($80) to confirm seal vs. line before committing to any repair
- Possibly upgrade to AN/braided lines when I do fix it so I'm not chasing it again

Questions for those who've been here:
1. Does a slow weep like this realistically hold for months on careful monitoring, or did yours accelerate fast?
2. Anyone have it diagnosed as "internal seal / replace turbo" when it turned out to just be the external fitting/line?
3. For ~90-min highway drives, anything beyond "full before you leave + watch the gauge + carry coolant" you'd recommend?

Thanks in advance – trying to nurse it safely until I can afford to do it right.

View attachment 87300

I bought a new 2015 Expedition Limited 4x4. Never wrecked and passenger use only (no towing).

One of the turbo coolant lines began to leak coolant. I had the Ford Premium ESP, which covered the repair. (At the same time, the engine vacuum pump began to leak oil - also repaired). This was in the 70,000 - 80,000 mile range.

I recall the turbo coolant line was an involved repair, and the mechanic at Ford broke several exhaust manifold bolts during the repair. The ESP paid for the repair and the extra labor charge for repairing the broken bolts. The turbo had to be removed or loosened, but not replaced.

The line wasn’t leaking a lot, but I noticed small drips on the garage floor and also the engine coolant reservoir dropped about 1-2 inches in a week.

I don’t know if the coolant leak would accelerate quickly, as I took mine to the dealer and said fix it.

I’d be leery of making a 90-mile drive with the leak. Coolant leaks can worsen and where your engine is leaking is a difficult repair area. I am always cautious and do not risk a long drive with a known issue such as leaking coolant.

I wish you the best. Good luck.

Fastcar · Thursday at 1:29 PM

H60John said:
Hey all, wanted to lay out my situation and see if it lines up with what others have experienced.

Truck: 2015 Expedition Platinum, 3.5 EcoBoost, ~121k miles.

Background: Bought it ~7 weeks ago. Had a timing cover reseal / rear main / oil return pipe done right after purchase (warranty work). An oil drip showed up the day that job finished but has since resolved – no more oil.

Current issue: Now I've got a COOLANT leak (orange Motorcraft, bitter/watery) weeping at the driver-side turbo area. Symptoms:
- Only shows up after the truck is warm / driven, dries up overnight
- Drips a small contained spot on the driveway (~fist-size an hour after a drive), not a puddle or trail
- Coolant reservoir is holding steady
- NOT overheating, temp gauge normal
- Visible orange staining + a fresh droplet at the fitting near the turbo

Diagnosis so far: Dealer says left turbo internal seal, $1,833 to replace the turbo. Christian Brothers quoted $1,775 (Ford reman turbo, ~$700 labor) but that was off the dealer's diagnosis, not their own look. I have NOT confirmed whether it's actually the internal seal vs. the external coolant line/jiffy fitting/O-ring – from what I'm reading those clip-in fittings are the usual culprit and a much cheaper fix.

My plan (can't afford the repair right now, looking at ~a year out):
- Monitor reservoir level (check cold) + watch temp gauge
- Keep a jug of coolant in the truck, top off as needed
- Avoid long hauls / towing where I can (typical drive is ~90 min)
- Pay for a cooling-system pressure test ($80) to confirm seal vs. line before committing to any repair
- Possibly upgrade to AN/braided lines when I do fix it so I'm not chasing it again

Questions for those who've been here:
1. Does a slow weep like this realistically hold for months on careful monitoring, or did yours accelerate fast?
2. Anyone have it diagnosed as "internal seal / replace turbo" when it turned out to just be the external fitting/line?
3. For ~90-min highway drives, anything beyond "full before you leave + watch the gauge + carry coolant" you'd recommend?

Thanks in advance – trying to nurse it safely until I can afford to do it right.

View attachment 87300

Fastcar · Thursday at 1:35 PM

Were it me I'd run it. As 17Expi says, it is probably one of those little O rings. Keep a jug of water with you just in case and keep an eye on it. No stop leak!! I'm surprised the dealer didn't want to sell you an engine.

H60John · Thursday at 6:33 PM

17expi said:
I agree with your "plan" except for the $80 coolant check, which won't tell you anything you don't already know, and braided lines won't do anything other than make your wallet lighter. It's probably one of those little O rings in one of those tubes that you can fix yourself. Pretty common leak and nothing to worry about.

You are right, I mean we can already tell where it’s coming from. I appreciate it!

H60John · Thursday at 6:35 PM

Fastcar said:
Were it me I'd run it. As 17Expi says, it is probably one of those little O rings. Keep a jug of water with you just in case and keep an eye on it. No stop leak!! I'm surprised the dealer didn't want to sell you an engine.

100% surprised as well! I tried to call them and they said they have seen new cars go 1000 miles and need new engines so I should have bought a warranty if I wanted protection. I appreciate the input!

H60John · Thursday at 6:40 PM

99WhiteC5Coupe said:
I bought a new 2015 Expedition Limited 4x4. Never wrecked and passenger use only (no towing).

One of the turbo coolant lines began to leak coolant. I had the Ford Premium ESP, which covered the repair. (At the same time, the engine vacuum pump began to leak oil - also repaired). This was in the 70,000 - 80,000 mile range.

I recall the turbo coolant line was an involved repair, and the mechanic at Ford broke several exhaust manifold bolts during the repair. The ESP paid for the repair and the extra labor charge for repairing the broken bolts. The turbo had to be removed or loosened, but not replaced.

The line wasn’t leaking a lot, but I noticed small drips on the garage floor and also the engine coolant reservoir dropped about 1-2 inches in a week.

I don’t know if the coolant leak would accelerate quickly, as I took mine to the dealer and said fix it.

I’d be leery of making a 90-mile drive with the leak. Coolant leaks can worsen and where your engine is leaking is a difficult repair area. I am always cautious and do not risk a long drive with a known issue such as leaking coolant.

I wish you the best. Good luck.

I appreciate the input. I am very glad you had coverage!
I may shift priority here to repairing my wheel bearing on my Ford edge while I save up for the turbo line repair.
I was hoping to drive both of them until the wheels fall off. Good thing I didn’t say until the turbos have issues
(Trying to stay positive here)

H60John · Thursday at 10:06 PM

here is a better picture do you guys think internal or external?

17expi · Thursday at 10:23 PM

H60John said:
here is a better picture do you guys think internal or external?
View attachment 87303

It's hard to say where it is coming from with a picture or even being there but it's just one of the cooling line O-ring seals and you could do it yourself., It shows you how on YouTube and the parts are cheap........not internal. Myself; I probably wouldn't fix it. Go on vacation over the mountains and don't worry about it. Just watch the coolant level once in a great while.

bityw · Monday at 12:31 PM

H60John said:
Questions for those who've been here:
1. Does a slow weep like this realistically hold for months on careful monitoring, or did yours accelerate fast?
2. Anyone have it diagnosed as "internal seal / replace turbo" when it turned out to just be the external fitting/line?
3. For ~90-min highway drives, anything beyond "full before you leave + watch the gauge + carry coolant" you'd recommend?

Thanks in advance – trying to nurse it safely until I can afford to do it right.

Disclaimer: YMMV.....literally.....

1. I have a 2015 XLT EL with this same issue on the passenger side turbo. It started leaking around 90k miles and has remained steady since then. It leaks more in the winter than it does in the summer. It only leaks when parked and cooled down, not warmed up or while in operation. I never got around to fixing it, and I'm at 205k miles now. I have maybe been through about 6/7 jugs of coolant in the past 5 years. I buy the cheap Supertech stuff from Walmart with the Dexcool logo. The cost of those 7 jugs over the years and miles hasn't been cost prohibitive.

3. I routinely use this vehicle in the summer to tow a boat sometimes ~90 miles one way to the lake and have only ever monitored the level and added as needed when cold before the weekend starts. I have also driven it all day over ~900 miles (AR to CO) having only topped it off the night before during my pre-trip walkaround.

TL;DR: Your first two points in your plan sound fine. That's all I've been doing on mine for awhile now.

Utah Driver · Monday at 10:15 PM

That picture looks like it shows a new pipe going to the turbo.

Utah Driver · Monday at 10:17 PM

The turbo also doesn't look like the original and not very old.

BlackBetty · 2026-06-09T13:28:10-0400

Judging from your pic it does look like it’s coming from the oil cooler line at the top. I’ve done this job before, and it’s not that bad.

Get new O-ring, bolts, and gaskets from dealer. A few days before actual repair start spraying all the fasteners. This can help get through some of the corrosion/ dirt for easier removal. I suggest finding Kroil penetrating oil. I’ve used many of the shelf brands, but it wasn’t until one of the guys at work gave me a can of Kroil that I felt I used something awesome!!! Used this to break fasteners loose on Apache helicopters.

Never seen it in the auto parts store. Only available on-line as far as I can tell. Anyway… tried to remove an exhaust downpipes fastener with no avail. Sprayed it Kroil, moved to the turbo oil/ cooler lines. By the time I got done with those the downpipe fasteners came right off.

Works well if you have a lift available. Easier on the back and/ or shoulders. The vehicle can be raised/ lowered to better accommodate you.

That leak can possibly get worse. I’d recommend changing it, but if money, tools, parts, or skill play a part it’s understandable. Also, keep in mind you know what’s going on so it’s not a problem to keep an eye on the coolant level. If you have a wife, girlfriend, or anyone that drives the vehicle they might not know to check; or how. That could be detrimental!!!

Should you decide/ when you’re ready to do it reach out; I’ve got all the torque values for all the fasteners.

17expi · 2026-06-10T00:21:48-0400

The trick to using penetrating oil is to attach a soaked rag to the part and let it sit overnight. I see people spray more and more on the bolt etc like it is going to build up or something, and it makes me cringe. Kroil is good but others are good too.

2015 Expedition 3.5 EcoBoost – slow coolant leak at driver-side turbo, looking for input

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