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Re: [T3] AAR Resolved, and some questions about idle.

Dave Hall wrote:

>Hope that's the case - it is bound to help anyway.
>I'd be worried to dismantle one the way Russ said, let alone with a saw as Toby
>did.  Since I don't have auto it won't be a problem for me.
>I wonder what aspect of an auto needs that electrical AAR rather than the
>oil-heated one that the manual FI uses.
Pure speculation here, but I would venture to say that the automatic AAR
is more apt to shut quickly than the manual because it's not dependent
on the engine oil heating up to close it. Having an engine idling at
1500+ rpm and holding it with the brake while the engine is attempting
to spin at that speed is nether good for the engine nor for the torque
converter. If the engineers at VW wanted to make sure that the engine
stayed at a high idle no longer than necessary, an electrically heated
AAR would be a good, predictable way of doing that.

Russ would know better, but ISTR that the early automatics had higher
failure rates due to overheating of the torque converter. One aspect was
the design of the TQ- early ones didn't have the same fins as the later
ones. Another aspect is possibly the high idle speed while the engine is
cold, and having to have the TQ work on a higher RPM longer than needed.

Note that in our automatics, the fluid doesn't run through a radiator to
cool it. The tranny has to keep itself cool however it can.

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