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
|