Nope not under warrantee...that ended on the year of my birth back in 86' I plug it in for....8 minutes...and car immediately fires over...like clockwork...in ten minutes the block heater hasnt even done its full work...I think one of the plugs is good...while the other three are old. Is it possible for a glow plug to still work, but be fouled (like a spark plug) or are glow plugs either a work or don't work device? 8 minutes wouldn;t be long enough for block heater to do it's stuff..