JB:
My guess is that the duckbill drains under the vents are cloged with dirt.
The rain filled them with water and with the high humidity level it only
needed a bit of engine warmth to turn the trapped water to fog.
An explanation worthy of Carl Sagan "Billions and billions of water
molecules captured on a MKII windshelid......"
Paul Burr
on 9/23/01 7:20 PM, James Barrett at jamesbrt@mindspring.com wrote:
> Folks,
> Started up my Tiger at noon Wensday and after
> driving a few seconds, the inside of the windshield
> (on the driver's side only) started fogging up at the
> bottom. I drove about a block and stopped. At that
> point substantial steam came out of the defroster.
> The outside temperature was about 87 F and the Tiger
> had not yet warmed up. I turned on the defroster
> fan to clear the windshield and drove for another
> 10 minutes or so. No more steam seemed to be comming
> out. I pulled into a parking lot, with a plan to
> bypass the heater core by looping one of the heater
> hoses back. Did not smell the antifreeze that would be
> typical of a leak. Decided that it was too unsafe to pull
> the radiator cap due to the pressure. Drove on home,
> hoping that I would not have problems with overheating.
> No additional steam appeared and I had also turned the blower
> motor off. When the Tiger cooled, there was no evidence
> of a leak or low water. (I have an overflow tank in addition
> to the regular Tiger side tank).
> I fabricated a test tool from a long (cross drilled)schrader
> valve soldered in a brass fitting and a pressure gauge. I inserted the
> open end of the schrader valve in the overflow hose and
> then pressurized the cooling system to 15 psi. In a few minutes
> the pressure dropped to 13 psi ( which is the radiator cap rating).
> It then set at 13 for several hours. Overnight it dropped back to
> zero. No evidence of any water leak from the heater core.
> Problem has not re-occured.
> Note that that morning there was a lot of rain and
> flooded streets due to a tropical storm. However; it is not
> uncommon to have a lot of rain here and the steam problem
> had never occured before.
> Any ideas?
>
> James Barrett Tiger II 351C and others
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