“Under the Hood” is heard every Saturday on WTYM AM 1380 / FM 103.7 from 10AM until Noon. Chris, Shannon, and Russ take your calls about vehicle repairs.
Dear Motor Medics,
I have a 2005 Chevrolet 2500 truck with a 6.0 engine and automatic transmission. Lately I have been experiencing a noise behind the dashboard upon starting. At first I thought it was under the hood and searched for something that could make the kind of sound I was experiencing. After much searching I discovered it was coming from behind the passenger side of the dashboard. It is located just to the right of the glove box door and back by the firewall. There is a box there that I assume is part of the heating system and when I touch it I can feel the clicking in sync to the noise. This noise occurs each time I start the vehicle and lasts for about one minute. Have you ever heard a noise like this before?
Scott in Denver Colorado
Dear Scott,
Yes we have heard this noise before and can help you. Most vehicles went to fully electrically operated heater door systems in the late nineties. The door motors have position sensors in them and when they fail the computer does not know where the door position is. Because of this failure the door motor keeps moving when at the end of its travel and begins to strip the gear teeth causing the noise until the module shuts it down at a pre-determined time limit. To fix the noise you will likely need a new door motor. Thanks for the email Scott.
Take care. The Motor Medics
Dear Motor Medics,
I have a 2002 Volkswagen Beetle with the 4 cylinder 1.8L Turbo. The engine runs great but I have a check engine light on with a code P0411 stored in memory. This code is for the secondary air injection system. The air injection pump runs and the hoses look good. I have been told it might be the check valve but I can’t seem to locate this. Have you heard of this problem on Beetles and can you help me locate the elusive “check valve” and am I going in the right direction? I listen via your web site; you guys do a great job.
Rodger in Florida
Dear Rodger,
I am familiar with the problem you are having and it is common to many vehicles with a secondary air injection pump. Cars in the southern climates don’t seem to be bothered by it as much as cold weather states but none the less it happens. The vehicle could have a bad air diverter check valve but it could be as simple as condensation in the air hose between the pump and the valve. The air valve is located on the engine at the passenger side rear just under the top cover. Remove the hose and check it for water, then clean it out if it is present’ reinstall it, and see how it works. You will need to have the codes cleared before the system will operate and run a self-test.
Take care, the Motor Medics