possible to remove turbos?

[hutchwilco]

Hi there,
I'm looking at buying a 94 twin turbo legacy gt.
I was wondering if there are any common problems with these engines
after a bit of use (120k kms) i have know other turbo engines to be
costly to repair, when a turbo fails in some way - is it possible to
remove the turbos if they cause trouble? or bypass them?

thanks for any advice,

 

[Carl 1 Lucky Texan]

Hi there,
I'm looking at buying a 94 twin turbo legacy gt.
I was wondering if there are any common problems with these engines
after a bit of use (120k kms) i have know other turbo engines to be
costly to repair, when a turbo fails in some way - is it possible to
remove the turbos if they cause trouble? or bypass them?

thanks for any advice,

That's an awesome car - keep it like it is!

Ask around also at www.ultimatesubaru.org and maybe at www.nasioc.com .

Carl

 

[wrx]

Hi there,
I'm looking at buying a 94 twin turbo legacy gt.
I was wondering if there are any common problems with these engines
after a bit of use (120k kms) i have know other turbo engines to be
costly to repair, when a turbo fails in some way - is it possible to
remove the turbos if they cause trouble? or bypass them?

thanks for any advice,

It would probably be more expensive to properly bypass a failed turbo
than to buy a replacement turbocharger. I had a turbo failure only once
-- an 85 Mazda 626GT. I was lucky that the thing would even run like
this, as often, you'll get oil and/or coolant leaks when a turbo fails.

Even so, it ran very, very poorly in that mode. That's because the
turbo became an obstruction in both the exhaust and intake when its
bearings went. Even if you do bypass it (both intake and exhaust) and
fix those issues, you have to remember that turbo motors are optimized
for turbo operation, most notably in the form of a lower compression
ratio, which hurts both off-boost performance and gas mileage.

FYI, I eventually fixed that Mazda myself, by buying a replacement
"cartridge", which is essentially just the bearings (which is what
failed) and turbine wheel and compressor housing, IIRC.

 

[y_p_w]

It would probably be more expensive to properly bypass a failed turbo
than to buy a replacement turbocharger. I had a turbo failure only once
-- an 85 Mazda 626GT. I was lucky that the thing would even run like
this, as often, you'll get oil and/or coolant leaks when a turbo fails.

Even so, it ran very, very poorly in that mode. That's because the
turbo became an obstruction in both the exhaust and intake when its
bearings went. Even if you do bypass it (both intake and exhaust) and
fix those issues, you have to remember that turbo motors are optimized
for turbo operation, most notably in the form of a lower compression
ratio, which hurts both off-boost performance and gas mileage.

This reminds me of the guy who asked about any way of shutting off the
turbo in order to tow. Of course towing would be a reason why you'd
want a turbo.

It's so integrated into the engine, electronics, and exhaust that it
would be a PITA to try and remove it only to end up with a severely
underpowered engine. I don't remember if this particular turbo is oil
or water cooled. If it's oil cooled, a cool-down cycle before
shutting down could help prolong turbo bearing life.

A failed turbo isn't that difficult to rebuild or replace. I haven't
done it myself, but I understand that most simply bolt-on. The engine
itself is built to withstand the additional stresses from a turbo. A
new one would be under $1000, but it should be far less than that to
have an older one rebuilt if only the bearings are bad.

 

[wrx]

This reminds me of the guy who asked about any way of shutting off the
turbo in order to tow. Of course towing would be a reason why you'd
want a turbo.

It's so integrated into the engine, electronics, and exhaust that it
would be a PITA to try and remove it only to end up with a severely
underpowered engine. I don't remember if this particular turbo is oil
or water cooled. If it's oil cooled, a cool-down cycle before
shutting down could help prolong turbo bearing life.

A failed turbo isn't that difficult to rebuild or replace. I haven't
done it myself, but I understand that most simply bolt-on. The engine
itself is built to withstand the additional stresses from a turbo. A
new one would be under $1000, but it should be far less than that to
have an older one rebuilt if only the bearings are bad.

I made this repair back in the early 90s...shopping around, I was able
to find a kit for around $700 back then. Conceptually, it was simple,
but it was a major PITA, thanks to almost no room to work under the hood
or from below (I skinned every knuckle) and the exhaust bolts had become
almost fused on.

 

[y_p_w]

It would probably be more expensive to properly bypass a failed turbo
than to buy a replacement turbocharger. I had a turbo failure only once
-- an 85 Mazda 626GT. I was lucky that the thing would even run like
this, as often, you'll get oil and/or coolant leaks when a turbo fails.

Yeah. There would probably need to be some sort of spacer to direct
the exhaust that would normally drive the turbo. Not to mention tying
off the oil and coolant lines. So this would be like a vasectomy for
the car. ;-)

Even so, it ran very, very poorly in that mode. That's because the
turbo became an obstruction in both the exhaust and intake when its
bearings went. Even if you do bypass it (both intake and exhaust) and
fix those issues, you have to remember that turbo motors are optimized
for turbo operation, most notably in the form of a lower compression
ratio, which hurts both off-boost performance and gas mileage.

Not to mention the electronics. The engine control module would
probably default to a "limp home" mode unless it were properly
remapped.

FYI, I eventually fixed that Mazda myself, by buying a replacement
"cartridge", which is essentially just the bearings (which is what
failed) and turbine wheel and compressor housing, IIRC.

It shouldn't even cost too much to have a mechanic do that. Most
accounts of turbo failures seem to just be the bearings. I've looked
up what comes in most kits, and it's usually just the replacement
bearings and gaskets. The biggest problem seems to be when a mating
surface is scored and needs to be machined, or so I hear.