clunking noise when i turn on heat.

[sharky512345]

Okay, sometimes when I turn on my car I get a clunking noise from under the hood. This does not happen every single time that I turn on the car but maybe around half of the time. I am pretty sure that it has to do with turning the thermostat on because I started it today with the thermostat off, started the car (it didn't clunk), and then directly after I turn the thermostat on there is a single clunk from under the hood and everything is fine after that.

I am not sure if it has to do with the outside temperature, because most of the time it is below freezing outside, but I believe that it has clunked when I have started the car when it was around 60 degrees outside.

There haven't been any other issues with the heat/air conditioning not working correctly or anything. Everything has worked fine, except for this single clunk that sometimes happens.

I hope that this all made sense, and thanks in advance for your help.

[n00b on demand]

Does it only do this when the engine is cold or when its warm also? Subaru's are known to make funny noises when a cold engine is started.

Are you hearing this clunk when you are inside or outside of the car? If inside, try having someone else turn it on while you are outside with the hood open. I'm betting that it isn't coming from under the hood, but rather from under the dash. As many of these SVXen get older, more and more people are experiencing some kind of failure with the climate control doors... i.e. the flaps that open and close to redirect the airflow. One or two may be sticking, and then at the last moment popping open, thus making a clunk sound.

If you can, try turning it on with your head under the driver's side dash. Does the clunk get louder? Try the passenger side too. If it's a lot louder down there, then it's probably the little climate control doors.

[sharky512345]

Yes, i am pretty sure that it only makes the noise when it is cold outside. I checked again this morning. I turned the car on, then waited about 30 seconds then turned the heat on and it clunked right when i turn the heat on. Does anyone elses svx do this?

[dcarrb]

I second deruvian's post... you're hearing an airflow door.

dcb

[sharky512345]

okay, so if it is an airflow door that is making this noise, then how would i go about fixing it?

I will check what you said, deruvian, to try and see where the noise is coming from for sure.

Originally posted by sharky512345
okay, so if it is an airflow door that is making this noise, then how would i go about fixing it?

I will check what you said, deruvian, to try and see where the noise is coming from for sure.

The climate control system has a diagnostic mode. Go to http://svx-iw.com/ and click on "Codes". Then click on "Climate Control".

[sharky512345]

Originally posted by deruvian


The climate control system has a diagnostic mode. Go to http://svx-iw.com/ and click on "Codes". Then click on "Climate Control".

Thanks for the link. I will try doing that tomarrow, its too dark outside right now for the test to work.

[sharky512345]

Okay, it was finally light enough that i could do the climate control test. It brought up 00 meaning everything was fine. But it still clunks when i turn it on when it is cold outside. (single clunk upon turning defroster on, haven't tried any other modes).

I put my head down by the pedals this morning when i turned the defroster on, and the noise was actualy quieter, i could try the same with the passenger's side tomarrow. It only does this once every day when the first time i turn on the defroster, then even if i turn it off and back on it won't do it again. Or if i turn the car off and back on it won't clunk again, so i am a little confused about all this.

Is this enough of a problem that I should worry about fixing it or am I just paranoid about anything breaking?

[dcarrb]

Originally posted by sharky512345

Is this enough of a problem that I should worry about fixing it or am I just paranoid about anything breaking?

It's probably just a door sticking for a moment, then clunking home. My heater whistles like a old steam radiator for sevaral minutes every morning, but it works just fine, so I figure this just adds to the character of the car.

Remember, even the newest SVX is getting pretty old. If I were you, I'd save my money and energy for more important maintenance issues that are bound to arise down the road.

dcb

[sharky512345]

okay, thats what I was thinking as well. Thank you everyone for all your help.