Will overheating kill your water cooled alternator?

A6 All/ S6 All
#1

Title says it all. Will it?

#2

What overheating scenario are you referring to:

  1. loss of coolant due to hose or connection failure
  2. loss of flow due to failed (or failing) water pump
  3. loss of cooling capacity due to stuck thermostat or plugged radiator passages

I have personally had the first two scenarios occur on my S6 and the alternator is still functioning within spec.

#3

The 3rd one (thermostat) but u pretty much answered it. Just thought too much coolant heat can harm it since it’s water cooled.

#4

It is much more likely to do engine damage from over heating than kill the alternator. At least right away but overtime with multiple thermostat failures it definitely wouldn’t help the alternator life.

By the way, I found that a Hitachi alternator from a B6 (2005)/B7 S4 will fit on a C6 S6 and work fine. SIX6SIX’s car had a terrible noise coming from his V10 alternator, it also wasn’t charging the battery correctly, and there were no V10 replacement alternators in the USA at the time so I installed a used B6 Hitachi alternator from my parts car B6 S4 wagon. The amperage rating, belt pulley, bolt holes, and physical dimensions are the same. There are three differences. One is that the rear metal coolant pipe fittings are different so the V10 coolant pipe nipples need to be transfered to the alternator just like any replacement anyways. The B6/7 S4s use angled metal coolant pipes that are longer and angled to fit the corresponding rubber coolant lines as the V10s use straight out metal coolant pipe fittings since the rubber hoses go right up to the back of the alternator. The second difference is that the electrical connector and battery positive cable connect differently. The V10 alternator has those two connect off to the bottom of the passenger’s side for better access as the V8 has them connect on the middle back for the battery positive cable and the electrical connector plugs in at a different angle. Then the biggest difference is the availability since usually there are one or none of the V10 alternators on the country as there are a bunch of B6/7 S4 alternators available. At the time there was also a few hundred dollars price difference but that seems to have changed.

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#5

FYI - all of the above applies to Gallardo V10’s of the same vintage (and presumably R8’s) with the same mods that Bones outlines

#6

Thanks Jimmy! I appreciate all that helpful info.:+1:well done