[s-cars] A4 heat question

[mtgadbois at aol.com]

 S-heads,

Since some of you are multiple Audi car owners I thought you may have the solution.  The sacrificial 01 A4 that the kids use has little to no heat.  I've flushed the heater core several times - flows nicely.  My heat probe says one hose is about 150F while the other is 110F.  I was wondering if there is a vacuum controlled coolant flow valve in the A4 just as there is in my S6?  Any BTDT that doesn't require replacing the heater core?

Thanks,

Mark near Chicago (I'm warm but they won't be)