Forester Sports 2.5XT-turbo-induced blown engine?

[fastdude]

Anyone else experience a turbo-induced blown engine?

 

Our 2007 Sports 2.5XT suffered a blown engine last week as I was driving from San Francisco to Long Beach, and I'm wondering if anyone knows of similar events with other Turbo XT's. The dealer's mechanics where I had it towed to had to do an engine tear-down, and found that cylinder 4 was trashed, with a big chunk of it loose (Picture attached). Their opinion is that, since this cylinder works most closely with the turbo unit, the cylinder was constantly overheating. (Note: I'm not a car techie, so I realize my description may lack proper details, but I'm going by what I've been told over the phone.) Metal fatigue due to over heating apparently is the specific cause of the failure The engine block is not repairable.

 

The dealer has quoted me a total price over $6000 complete repair. I am talking to Subaru America, as I am disappointed that the engine design may be partially responsible for this massive failure.

 

Does anyone know of other turbos causing engine block failure?

 

This Sports 2.5XT has got 136K miles, and has only been serviced by Subaru garages. We got it new in 2007. All driving has been on streets and highways.

 

We still have a 1999 Forester (non-turbo), which chugs along nicely with about 150,000 K.

[86BRATMAN]

Broken ring land, were there any performance mods done to the car?  Its a problem in the STi's when you start making a decent bit of power.  I've not seen a piston broken by overheating, you would have had other problems before this reared its head.

[fastdude]

86bratman, No mods have been done to this car. Just routine, regular servicing by Subaru mechanics.

[Gloyale]

#4 cylinder is opposite side from the turbo.  And All the cylinders should see boost the same.  #3 cylinder is the one actually closesest to the turbo.

 

IDK........not nessecarily a design flaw........definately bad luck.  Turbos are generally more prone to all types of failures, but espescially ring lands.

 

It's hard to tell from one photo.  But I wouldn't think that the block would be too damaged if you spoob it down right away.  Pistons break and are repaired all the time.  Labor intensive, but cheaper than a whole new engine.....the case doesn't need to be split.....just pull the wrist pin, put in a new piston/rings and put some heads on it.

[chaz345]

#4 cylinder is opposite side from the turbo.  And All the cylinders should see boost the same.  #3 cylinder is the one actually closesest to the turbo.

 

IDK........not nessecarily a design flaw........definately bad luck.  Turbos are generally more prone to all types of failures, but espescially ring lands.

 

It's hard to tell from one photo.  But I wouldn't think that the block would be too damaged if you spoob it down right away.  Pistons break and are repaired all the time.  Labor intensive, but cheaper than a whole new engine.....the case doesn't need to be split.....just pull the wrist pin, put in a new piston/rings and put some heads on it.

Not to mentiont the fact that even if we're talking whole "new" engine, $6k seems a bit steep.

[fastdude]

#4 cylinder is opposite side from the turbo.  And All the cylinders should see boost the same.  #3 cylinder is the one actually closesest to the turbo.

 

IDK........not nessecarily a design flaw........definately bad luck.  Turbos are generally more prone to all types of failures, but espescially ring lands.

 

It's hard to tell from one photo.  But I wouldn't think that the block would be too damaged if you spoob it down right away.  Pistons break and are repaired all the time.  Labor intensive, but cheaper than a whole new engine.....the case doesn't need to be split.....just pull the wrist pin, put in a new piston/rings and put some heads on it.

Have you ever heard of a dealer doing what you suggest, when they are the one's recommending full block replacement?

[Fairtax4me]

Broken piston crown is usually due to detonation. More commonly known as "Pinging".

 

If the fuel mixture in the cylinder goes lean under boost this is what you end up with. The other leading causes of detonation are low octane fuel, and oil in the fuel mixture( Usually from leaking valve stem seals or worn rings).

 

Detonation causes a shockwave in the cylinder which can have the same effect as a hammer strike, and things get broken. Unfortunately that engine is toast. Might make a good glass-top coffee table!

 

Was it caused by the turbo? Absolutely not. This engine is designed to have a turbo, and to withstand the pressures created by the turbo.

[Gloyale]

Have you ever heard of a dealer doing what you suggest, when they are the one's recommending full block replacement?

 

No that would be too much labor for them, and they can't "garauntee" without replacing the block.  That's what dealers do....throw your money at the problem.

 

But if they will not replace the engine, and you want to explore options that would be the way to go.

 

The heads are more likely to need replaced than the block.

 

Find an independent shop that can do the piston replacement.

[uniberp]

Broken ring land, were there any performance mods done to the car?  Its a problem in the STi's when you start making a decent bit of power.  I've not seen a piston broken by overheating, you would have had other problems before this reared its head.

 

Do you know what kind of gas mileage you got?