|
The "grunt" you hear is probably the air pump. It sounds like it is filled with water. The air pump only runs for a less than a minute or so when you first start it up. The pump is shooting air into the cat converter to heat it up quickly. When the check valve sticks from the mountain of hydrocarbons that have blasted through it, the water residue slides down the hose to the air pump and settles in the housing. The grunt is probably the air pump motor moaning with the water build up. If it is the case, it will soon fail and your check engine light will come on to stay. I was thinking about drilling some small holes in the air pump casing to let the water have an exit dduring the neutral pressure when the car is not running. Sure enough, I went to Bay 13 and read where a guy did exactly that after replacing his air pump and he's had not problems since. so it isn't such a crazy idea. If you want to check to see if it's the air pump get below the car near the radiator on the drivers side and have someone start the car. The pump is attached to the fram just behind the radiator below where the battery housing is. You will hear the noise up close and personal if it is the pump.
|
