Mystery coolant leak continues

Phil Rose pjrose at
Mon Sep 2 11:24:44 EDT 2002

I agree with Kneale: the  MFTS  with coolant-shorted contacts (caused
by the previous leakage) would account for both of the current
problems--i.e., idiot light and A/C disfunction. The "lower front
middle" garage floor puddle is probably an unrelated thing.

Brice, have you inspected the interior of the MFTS rubber boot? Is it
full of coolant or show evidence of prior leakage? If so, pull off
the connector, then tighten MFTS and clean contacts. Driving around
for a brief time while the MFTS connector is off ought to
(temporarily) cure both symptoms (idiot light and A/C).


At 7:53 AM -0400 9/2/02, Kneale Brownson wrote:
>Multifunction temperature switch?  Compressor seals leaking?  Two separate
>issues coincidentally occuring?
>At 02:37 AM 09/02/2002 -0500, BriceW at wrote:
>>A few weeks ago I posted about a coolant leak of which I couldn't figure
>>out where it came from. Since then it has not leaked again.
>>But now, the low coolant idiot light comes on all the time. The coolant
>>reservoir tank is full and no leaks appear anywhere. Also at the same
>>time the AC is now only blowing hot air where it was very cool before.
>>And now the boost is only 1.3 where it was 1.7 before.
>>The water pump,timing belt and idler pulley were changed 6,000 miles ago
>>because of a seeping water pump. they were all OEM parts and the job was
>>done by a long time seasoned Audi mechanic.
>>There is a leak on the garage floor at the the lower front middle
>>drivers left side that looks like oil and coolant. It might be directly
>>under the AC compressor.
>>The car drives fine and the temp gauge never goes beyond right under the
>>half mark which is its usual. The temp switch was changed when the water
>>pump was done as was the thermostat.
>>I have been considering cutting the low coolant switch on the bottom of
>>the reservoir tank and seeing if the idiot light stays on still. Are
>>there any other switches or conditions that could cause the low coolant
>>light to come on?
>>I am very perplexed by this and don't quite know which way to proceed.
>>It would be great if it was just a bad low coolant switch and needing
>>new freon but I suspect something more. The initial coolant leak a few
>>weeks ago is what worries me the most. It hasn't leaked since. The tank
>>stays full but the idiot light continues on.
>>Which direction do I logically proceed?
>>Could a bad "new" water pump cause this?
>>What about the turbo pump?
>>Brice Warnick
>>91 200TQ20V 102,000
>>200q20v mailing list
>>200q20v at
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Phil Rose
Rochester, NY
mailto:pjrose at

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