Re: BMW Aluminum Cylinder Blocks

[Chris Guy <Cguy1@xxxxxxxx>]

>Is it true that BMW is manufacturing 2.5 liter engines with
>aluminum sleeveless cylinder blocks? 

Yes

>And that BMW engineers
>are worried that high sulfur U.S. auto gas will cause
>premature wear on these engines? 

Yes

>And that a quiet recall of
>the few vehicles already in the U.S. with such cylinder
>blocks is currently occurring?

I don't think so.

There is a campaign to extend the warranty of all aluminum block V8's in 
the US. BMW changed the computer codes and the lining material/process 
(from Nikasil to Alusil) to fix this, but probably is still gun shy after 
all of the V8 work (BTW 'due to volume' a short 4.0 block dropped from 
about $12,000 to $4,000 for parts).

I think most of the Aluminum blocks sold in the US have iron cyl liners 
(most were iron blocks while europe had aluminum for a couple of years), 
but check the latest literature for that specific model. Some places 
overseas my have the same problems with the 6 that the US had with the V8 
(eastern europe?) due to high sulphur.

>What is the metallurgical
>difference between what BMW is doing versus what Chevy did
>with the Vega 25 years ago? Thanks.


The Vega rusted away before anyone noticed poor idle in the engine? Chevy 
dealers said they all do that? Actually the basic process is not to be 
that different, but refined processes and revised hardening 
material/process for the cyl wall are different.

Chris Guy
86 535i 5sp 

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