Anybody with an idea as to what is making a fairly loud and distinctive clunking noise coming from the passenger front area if the engine bay in cold weather when the car is started cold. It sounds maybe like a solenoid going on and off in about a 1 second interval. As the engine runs the intervals get slower until it finally stops in about a minute or so. Everything seems to be working but this is not a good noise.

Ideas? Thanks much!!!!

 

Need to raise the hood and listen . . .

Maybe a bad belt, worn pulley, loose power steering bracket, bad engine mount, worn water pump, dying cat . . . how'za bout some more info . . .

 

It's probably one of the belt tensioners. Mine was on the accessory belt. Have someone start the car while you look in there with a flashlight. You'll see the tensioner banging back and forth. Mine only did it in cold weather upon a cold start, then slowly quit after a minute, like yours. I replaced the tensioner and the belt, so I'm not positive which was the culprit. I thought the tensioner pulley might be spinning hard upon startup, but the belt seemed stiff too. Sounded like the engine was coming apart!

 

Mine shows similar symptoms, the serpentine belt slips slightly on the idler pulley, causing a thumping noise for 20 seconds to one minute after starting (depending on how cold it is out). I've tried both plastic and metal replacement pulleys to solve this, with no luck. I'm going to look for a pulley with the original "lip" next.

 

Hey guys, sorry to make this such a confusing issue - I'm talking only about "AUTO" mode (the Subaru calls it "FULL AUTO")
The last several cars I've owned (Jaguars, Subarus, Toyotas), had this vent arrangement (controlled by blend doors):
defroster (front/side)
dash (2 near the center)
dash (2 near the sides)
rear seat (back of center console)
floor (front and rear).
I've driven for years with a center and side vent each blowing on my hands, and occasionally checking the rear seat vent, so I know this is the way it has worked in my cars:
- when the system is trying to raise the temperature in the car, heated air comes through the floor vents and the two dash side vents..
- when the system is trying to lower the temperature in the car, cooled air comes through all the dash vents and the rear seat vent.
The system decides when to send air through the defrost vents through some space-age technology.
The Subaru has a display that constantly shows which vents are open (even in FULL AUTO mode), so easy to verify - raise the temp, the center vents close; lower the temp, they open.
In the Jaguar, you have to crank the temperature way up or way down, and see where the air comes out. (A technician once told me, regarding my '09, that there is also an outside temperature sensor input, further complicating the system's decision-making).

My only issue is that my Jaguar, when it's first starting, doesn't seem to know whether it's supposed to be heating or cooling (maybe set temperature is too close to cabin temperature), so some air comes through all the dash vents.
Whereas, on the Subaru (in cool weather), the dash vents are closed tight until the system decides it's good and ready.
Anyway, thanks for your interest, but certainly not worth all this commotion.
You may return to your regularly scheduled acrtivities...

 

Please disregard - the previous reply got attached to the wrong thread/wrong forum.
Sorry for the interruption!
Dick