2015 Legacy head gasket problems

[Ernesto2.5]

Anyone else having head gasket issues on their 6th gen legacy? I took mine in for a diagnostic inspection and it turns out one of the headgaskets is leaking coolant and oil. The car is currently at 96,000 miles and it surprises me Subaru is still having these same issues as their EJ motors. None the less Im lucky I bought the extended warranty because now the warranty company has to pay for a 13.5 hour job. And yes the job was approved. Now let's see how long they'll take. 

[ncted]

No issues with head gaskets on any of my Subarus over the years, including the EJ255 in my wife's 2011 Forester XT.  I cannot say the same for the Mazdas and Fords I owned in the past however.  I think, like anything, YMMV.

[ammcinnis]

13 hours ago, Ernesto2.5 said:

... one of the headgaskets is leaking coolant and oil.

That's really strange ... because there are not supposed to be any water passages through the head-to-block interface in the FB25 engine. Coolant is routed through the block and heads in parallel flow paths, rather than in series. See attachment.

FB25_Cooling_system.pdf

[tdelker]

1 hour ago, ammcinnis said:

That's really strange ... because there are not supposed to be any water passages through the head-to-block interface in the FB25 engine. Coolant is routed through the block and heads in parallel flow paths, rather than in series. See attachment.

FB25_Cooling_system.pdf 677.61 kB · 0 downloads

Not an expert here, but that image sure looks like the hot water is flowing from the head to the block through an internal passage, not through an external pipe.

[silverton]

5 hours ago, ammcinnis said:

That's really strange ... because there are not supposed to be any water passages through the head-to-block interface in the FB25 engine. Coolant is routed through the block and heads in parallel flow paths, rather than in series. See attachment.

FB25_Cooling_system.pdf 677.61 kB · 4 downloads

Oh buddy...they definitely have internal coolant passages. There's coolant passages into the timing cover as well.

All boxer engines will have the same problems when cared for improperly, it's not the car if you catch my drift, boxer engines are far more prone to head gasket failure because your oil literally pools at the seam, the older your oil is the more likely it is to escape, once escaped it doesn't stop.  I've seen many spotless EJ's from the early to mid 2000s with 100-130,000 miles and it's very clear that they're original.  Of course these are the cars that are changing their oil at 2400 miles instead of 3000.

18 hours ago, Ernesto2.5 said:

Anyone else having head gasket issues on their 6th gen legacy? I took mine in for a diagnostic inspection and it turns out one of the headgaskets is leaking coolant and oil. The car is currently at 96,000 miles and it surprises me Subaru is still having these same issues as their EJ motors. None the less Im lucky I bought the extended warranty because now the warranty company has to pay for a 13.5 hour job. And yes the job was approved. Now let's see how long they'll take. 

I see head gaskets failing on FB motors all the time.  Since you are under 100k, if you have been diligent with your service history (ie changing your oil every 6k per their recommendation, and doing the major services) they may help in some way.

[Ernesto2.5]

5 hours ago, ammcinnis said:

That's really strange ... because there are not supposed to be any water passages through the head-to-block interface in the FB25 engine. Coolant is routed through the block and heads in parallel flow paths, rather than in series. See attachment.

FB25_Cooling_system.pdf 677.61 kB · 5 downloads

That's interesting! I was having coolant loss so I took it for a diagnostic appointment. Turns out headgaskets are seaping

[Ernesto2.5]

3 minutes ago, silverton said:

Oh buddy...they definitely have internal coolant passages. There's coolant passages into the timing cover as well.

All boxer engines will have the same problems when cared for improperly, it's not the car if you catch my drift, boxer engines are far more prone to head gasket failure because your oil literally pools at the seam, the older your oil is the more likely it is to escape, once escaped it doesn't stop.  I've seen many spotless EJ's from the early to mid 2000s with 100-130,000 miles and it's very clear that they're original.  Of course these are the cars that are changing their oil at 2400 miles instead of 3000.

I see head gaskets failing on FB motors all the time.  Since you are under 100k, if you have been diligent with your service history (ie changing your oil every 6k per their recommendation, and doing the major services) they may help in some way.

I bought it pre-owned with 88,000 miles. Looks like previous owner was doing 7k oil change intervals.

[ncted]

22 minutes ago, silverton said:

Oh buddy...they definitely have internal coolant passages. There's coolant passages into the timing cover as well.

All boxer engines will have the same problems when cared for improperly, it's not the car if you catch my drift, boxer engines are far more prone to head gasket failure because your oil literally pools at the seam, the older your oil is the more likely it is to escape, once escaped it doesn't stop.  I've seen many spotless EJ's from the early to mid 2000s with 100-130,000 miles and it's very clear that they're original.  Of course these are the cars that are changing their oil at 2400 miles instead of 3000.

I see head gaskets failing on FB motors all the time.  Since you are under 100k, if you have been diligent with your service history (ie changing your oil every 6k per their recommendation, and doing the major services) they may help in some way.

So, what oil change interval do you recommend for the FB25 in my 2018 Legacy?

[silverton]

Every engine is different, but I would start with 3000 miles.  If at 3000 miles you're still full and the oil looks okay like you can still sort of see through it, go for 3750-5000.  If it's black/low... change it.  The fresh rebuilt in my 2001 just turned 13,500 and at my last interval which lasted about 3200-3300 miles, it's perfectly on the full dot, but darker than I'd like it to be, this was the engines 6th oil change.   Blackstone recommends between 3400-3600.

[anthonyparra]

DONT FORGET TO REPLACE PCV VALVE!!!!

USE 5W-30 OIL INSTEAD of 0W-20 !!!!!

I have a 2016 Legacy 2.5i Limited. It has 112k miles on it, it was my first car 2 years ago. the first year I had it, I would always redline the engine every day and whatnot. Now, one year later I decided that I really needed to do the maintenance because the car would not last.

I do 3k oil intervals because I want this car in top condition. I have never had any problems with this car besides it not being fast enough.  I suggest getting updated on your maintenance. check all your hoses, make sure you clean all your sensors. differential fluid change, tranny fluid change, all these things drag the engine down when you dont maintain them with fresh fluid. I changed my diff fluid after 60k and it felt like my car was 3 times faster, its just added weight.

Anywho, you should do your research, dont be dumb--its not a racecar--and just take care of your baby.