i am getting a funny smell, sort of like oil or coolant or gas, when i turn the heat on.
it is worse when i am at a stoplight and better when i am moving fast.
my mechanic flushed out the heater core with a hose, but that didnt help.
not overheating engine temperature is 90

my car has 245,000 k on it now, just wondering if anyone has any ideas?
should i assume i need a new heater core (1000 approx)
i am actually thinking of trying a portable heater rather than fix it
any thoughts?
thanks alot