all 2.5 heads eventually leak?

[bork]

Are there any years exempt from the HG problems?

[Fairtax4me]

To say they're exempt would be a mis-statement, but there are certain years that are more likely and certain years that are less likely to fail.

Eventually the head gaskets will fail on any engine, the normal service life seems to be around 200 - 250k miles, which tends to be the life of the vehicle. Subaru EJ22 head gaskets tend to make it to 300k and sometimes beyond on original gaskets due to their design.

 

Any early DOHC 2.5 known as the EJ25D, used most commonly in the Legacy Outback between 96 and 99, is almost guaranteed to have a head gasket failure by 150k miles.There are some rare cases of these where the head gaskets have lasted just as long as on any other engine.

The typical failure mode on these is for coolant to leak into the combustion chamber and be burned away by the combustion of fuel and air.

Generally these can be successfully repaired and the replacement gaskets will last the rest of the useable life of the car. Unfortunately, often the engine is damaged beyond repair because the head gaskets are not replaced at the first sign of failure, and the engines are driven to the point of overheating multiple times, or in some cases severe overheating, causing damage to the bearings in the engine. This results in catastrophic failure of the rod bearings, often causing rods to break and put a hole through the engine block.

 

The second generation SOHC 2.5 used in almost everything from 1999 to 2004 is susceptible to head gasket failure, but in a different way. These typically leak externally, or towards the outside of the block. It will mean occasional drips or signs of seepage of coolant around he head gaskets on the block. This is a manageable condition through the help of a cooling system conditioner required by Subaru for use in these engines.

As with the earlier design, severe overheating will cause internal damage, but the cases of severe overheating are less common because there are signs of coolant leakage that lead to the driver having the vehicle serviced before engine damage is done.

 

Of the newer EJ25 varieties from 2005 to current it is hard to say. These have not shown signs of head gasket failure in a widespread manner, but most of them are still below the typical failure mileage. A dealer will be the best informed of how these are holding up, because that's the first place owners of newer vehicles will go when their car has a problem. But so far, they seem to be much less problematic than the earlier incarnations of the 2.5.

[bork]

Very good clear response. Thank You ! So I'm gonna lean towards an older 2.2 or a 1999-up sohc 2.5

[idosubaru]

Very good clear response. Thank You ! So I'm gonna lean towards an older 2.2 or a 1999-up sohc 2.5

that's a very good idea. the DOHC's are problematic for a variety of physical and dynamic reasons.

 

welcome aboard, i'm in Morgantown, will be traveling I68 Wed of this week and next, i'm from Maryland.

[bstone]

To say they're exempt would be a mis-statement, but there are certain years that are more likely and certain years that are less likely to fail.

Eventually the head gaskets will fail on any engine, the normal service life seems to be around 200 - 250k miles, which tends to be the life of the vehicle. Subaru EJ22 head gaskets tend to make it to 300k and sometimes beyond on original gaskets due to their design.

 

Any early DOHC 2.5 known as the EJ25D, used most commonly in the Legacy Outback between 96 and 99, is almost guaranteed to have a head gasket failure by 150k miles.There are some rare cases of these where the head gaskets have lasted just as long as on any other engine.

The typical failure mode on these is for coolant to leak into the combustion chamber and be burned away by the combustion of fuel and air.

Generally these can be successfully repaired and the replacement gaskets will last the rest of the useable life of the car. Unfortunately, often the engine is damaged beyond repair because the head gaskets are not replaced at the first sign of failure, and the engines are driven to the point of overheating multiple times, or in some cases severe overheating, causing damage to the bearings in the engine. This results in catastrophic failure of the rod bearings, often causing rods to break and put a hole through the engine block.

 

The second generation SOHC 2.5 used in almost everything from 1999 to 2004 is susceptible to head gasket failure, but in a different way. These typically leak externally, or towards the outside of the block. It will mean occasional drips or signs of seepage of coolant around he head gaskets on the block. This is a manageable condition through the help of a cooling system conditioner required by Subaru for use in these engines.

As with the earlier design, severe overheating will cause internal damage, but the cases of severe overheating are less common because there are signs of coolant leakage that lead to the driver having the vehicle serviced before engine damage is done.

 

Of the newer EJ25 varieties from 2005 to current it is hard to say. These have not shown signs of head gasket failure in a widespread manner, but most of them are still below the typical failure mileage. A dealer will be the best informed of how these are holding up, because that's the first place owners of newer vehicles will go when their car has a problem. But so far, they seem to be much less problematic than the earlier incarnations of the 2.5.

 

Make this post into a sticky!

[bork]

that's a very good idea. the DOHC's are problematic for a variety of physical and dynamic reasons.

 

welcome aboard, i'm in Morgantown, will be traveling I68 Wed of this week and next, i'm from Maryland.

 

Funny , I bought the car from a tad West of Morgantown, Friedsburg or Friedrich? area. Drove it home an hour away, scarey! Needs a bunch of work, but it handles well.

[Caboobaroo]

BUT if you decide to get one that needs head gaskets, make sure to use a MLS head gasket. Only time I see one of those fail on an EJ25D, EJ251, EJ253 is when the vehicle has been abused by overheating, either by a blown radiator or bad water pump.

[1-3-2-4]

BUT if you decide to get one that needs head gaskets, make sure to use a MLS head gasket. Only time I see one of those fail on an EJ25D, EJ251, EJ253 is when the vehicle has been abused by overheating, either by a blown radiator or bad water pump.

 

 

Mine did not start overheating until I started pushing the car harder on the highway.. the crazy thing is I had one or 2 overheats before I took my 654 mile trip out to MI. Never overheated the whole way to and from.

 

It did start overheating more when then AC was on.

 

The worst was when the however rad hose blew and I got stuck made it to a rest stop and met up with some people that needed help as well, got a lift to get some supplies.

[1 Lucky Texan]

I'm gonna just throw out a coupla points. These are just thought experiments but might have a small amount of validity.

 

Subarus have 2-3 odd design features which, in addition the their overall longevity, contribute to the likelihood of someone experiencing HG failure.

 

They have decent utility and quality, that, eventually, someone may own the car that doesn't understand the need for 'burping'/special attention to coolant refilling. Also, the cars do not behave well with aftermarket thermostats. These increase the likelihood of overheating at some point in their life. Their utility also means they may get driven in road/environmental conditions that are more harsh than other vehicles. And, obviously, they have 2 headgaskets. In a 'raw' sense, that doubles the likelihood of experiencing a failure.

 

This does not excuse the poor performance of the HGs in the mid-late 90s, nor the external leakers in the period just after that. But, some of the above may contribute to a notion that, eventually, any/all Soobs are gonna need HGs. It may even statistically be true - but just because the Fiats, Suzukis and Kias of this world are long in the junkyard for other reasons BEFORE they have a chance to blow their gaskets, is not the fault of Subaru.

 

And before you think I'm just an apologist, I'm very upset at the failure of the secondary air valves in my WRX. Fortunately, I found a workaround out of the Subaru 'tuner' community. I COULD just replace the valves, but I have found no indication they have been redesigned/improved and I fear they will just fail again in 4 years.

Anything that can happen to any other car can happen to a Soob. In a general sense, I think they're well made. better than several cars I've owned and as good as the best cars I've owned. But not flawless.

[Caboobaroo]

Mine did not start overheating until I started pushing the car harder on the highway.. the crazy thing is I had one or 2 overheats before I took my 654 mile trip out to MI. Never overheated the whole way to and from.

 

It did start overheating more when then AC was on.

 

The worst was when the however rad hose blew and I got stuck made it to a rest stop and met up with some people that needed help as well, got a lift to get some supplies.

 

The OEM ones always leak which is true. I was referring to the MLS head gaskets on the N/A EJ25s.

[idosubaru]

Subarus have 2-3 odd design features which, in addition the their overall longevity, contribute to the likelihood of someone experiencing HG failure.

good points. subarus are simple to work on - alt, starter, power steering pump, pulleys, timing belt - everything is really easy IMO compared to transverse mounted annoyances - but the price you pay is twice the valve train and headgasket work! though this is really about the EJ25, not "Subaru's" in general. the thought experiment has almost nothing EJ25 specific in it. but you said it yourself, you know - there was some poor performance.

[johnceggleston]

subrus are not the only ones with extra valve trains and head gaskets.

 

there are lots of other engines with 2 head gaskets, V6s and V8s. probably not too many V4s though??.

 

does any one make a straight 6 any more?

[1 Lucky Texan]

subrus are not the only ones with extra valve trains and head gaskets.

 

there are lots of other engines with 2 head gaskets, V6s and V8s. probably not too many V4s though??.

 

does any one make a straight 6 any more?

 

doesn't Jeep have a straight 6?

 

man, I remember a coupla vehicles I drove, the 51 Chevy had HUGE amounts of room on either side of the straight 6 motor. But those vacuum wipers - ugh, horrible. The 64 Rambler I had was extremely reliable and fairly easy to work on. Older cars were not quite as binary in their failures, they would gradually let you know when things needed attention (but they needed attention almost all the time). Seems like many times nowadays, a car just stops. At least there's a computer on board that might tell you why!

[Caboobaroo]

I have found on the '05 and newer head gaskets don't last as long as the '00 - '04 before needing replacement as they start leaking oil sooner. Ive already replaced a few sets and they were all under 80k miles.

[1-3-2-4]

The OEM ones always leak which is true. I was referring to the MLS head gaskets on the N/A EJ25s.

 

 

My OEM failed around 226k dealer only has the MLS kind now

[Bluestone]

The indie shop that I used for some work on my Sube says that the cooling system conditioner treatment is just psychological….it doesn't really work but in my experience it does work for a few thousand miles and then the coolant seepage resumes.

Anyway, as I understand it, as long as the coolant level in the reservoir is kept up there's normally no overheating to contend with unless perhaps the thermostat, waterpump or radiator cooling fans fail or belts break. I'm referring here to the 2.5L engine of course.

This past summer I drove my 2000 Legacy wagon in 90-100˚ F weather for extended periods with the A/C going full blast and the temp indicator remained in the lower quadrant of the gauge…. the cooling system handled the hot weather driving with aplomb.

Edited December 20, 2011 by Bluestone

[bheinen74]

I have found on the '05 and newer head gaskets don't last as long as the '00 - '04 before needing replacement as they start leaking oil sooner. Ive already replaced a few sets and they were all under 80k miles.

 

Agree with what you say, they leak oil. So, either you deal with the oil burning off smell, and keep it topped off on oil (they weep not like a constant dripping) or change them out.

 

Maybe not use synthetic, since it is a thinner oil, maybe use regular oils instead of synthetic might decrease the leaks. My former 06 turned out to need headgaskets too before 100k, due to oil leaking.

[subsince77]

Agree with what you say, they leak oil. So, either you deal with the oil burning off smell, and keep it topped off on oil (they weep not like a constant dripping) or change them out.

 

Maybe not use synthetic, since it is a thinner oil, maybe use regular oils instead of synthetic might decrease the leaks.

 

that's an interesting idea. I like to use synthetic because of our extreme winter cold, and I figure it just protects better. But I wonder if running good quality non-synth would have any effect on the longevity of the HG's. No way to prove it one way or the other at this point.

[Caboobaroo]

My OEM failed around 226k dealer only has the MLS kind now

 

The shop I work for now sells full head gasket sets with the MLS gaskets. All the same stuff I would use on a customer car, you can buy as a kit and do it yourself.