What's a "blown turbo?"

[Jaywalker]

I read sometimes about a person blowing, or being afraid to blow, his turbo. What's that mean? What actually gets damaged - the bearings?

I owned an Audi 5000 Turbo once, and I was worried that it would blow up. Honestly, though, the turbo was about the only thing that didn't break, but that's another story.

If a 940 Turbo goes, for instance, do you replace the whole turbo, or do you rebuild it?

[matthew1]

I read sometimes about a person blowing, or being afraid to blow, his turbo. What's that mean? What actually gets damaged - the bearings?

Destroying it. Could be the blades on the impeller, bearings, or housing. Blades must be balanced pretty closely or else one side will pull, like when you're on a merry go round -- the faster you spin the more centrifugal force you feel pulling you outward. Now imagine that speed times 100 or more and you can see the need for near-perfect balance.

Many turbos go bad because of not enough oil or oil "coking", which is where the oil gets the lubrication baked out of it from high temperatures.

Typically, cars will operate with blown turbos, but not well and not efficiently.

If a 940 Turbo goes, for instance, do you replace the whole turbo, or do you rebuild it?

You can rebuild them if they're not too bad. There's a few threads in this forum on that.

[vegasjetskier]

EDIT: Matthew, I didn't see your post as I was typing. Oh, well, here's my answer:

As in most things, "it depends."

If your oil line gets coked up the bearings may seize and stop the turbine with no other damage. Or you could have a catastrophic failure and the turbine and compressor wheels could come into contact with the housings, ruining both. Or the bearing might tear itself apart and rip the seal causing your engine to suck oil and emit huge clouds of smoke. Or you could have Foreign Object Damage (FOD). Let's say you dropped a screw into the intake tube or your engine ate a valve and spewed the pieces out the exhaust manifold - there goes the compressor wheel or turbine.

So each "blown turbo" has to be evaluated as to whether it's rebuildable or not. Some require bearings, some wheels, some seals, some housings, and some are just junk.

[Jaywalker]

Very clear - thanks, both.

What's the cost of the parts for a worst-case, everything-must-go turbo replacement?

In case you haven't guessed, I'm tempted by a local Volvo Turbo which has recently had both its evaporator and heating coils replaced.

[vegasjetskier]

Very clear - thanks, both.

What's the cost of the parts for a worst-case, everything-must-go turbo replacement?

In case you haven't guessed, I'm tempted by a local Volvo Turbo which has recently had both its evaporator and heating coils replaced.

Well a complete, brand-new turbo for my car is about $725. But then my car has two of them.

What model and year are you looking at?

[Jaywalker]

It's a 940 - not sure of the year. Does the year make a difference?

[vegasjetskier]

A turbo for that car is about $600 rebuilt, $800 new. And it only has one turbo.