2003XC70 What is this intake gizmo?

carboncow · Post by **carboncow** » 06 May 2014, 20:40

Finished up the un-fun PVC refurb...the horror! Everything was clogged and in bad shape but I think we are in order now. Cleaned every single hose in site including the PTC nipple.

Anyways...I threw an intake code above 2000rpm (forget number) but found this little gizmo cracked up from us thrashing around. It separates from top to bottom (not sure why) and has a diaphragm inside with a long nipple. I put it in wrong the first time and threw the code...seems better with the nipple pointing up. Regardless it's cracked and zip tied together and very much could last this way forever but I"m sure I'll try to find a used/new one.

What comments/advice does anyone have?

Special thanks to "stew" for tag teaming this un-fun job. I still have to do a timing belt next and it will be a cake walk compared to this!

Post by **jimmy57** » 06 May 2014, 21:38

Brake booster auxiliary electric pump switch. Turns on the electric vac pump when vacuum goes below 10-12 inches of vacuum.

carboncow · Post by **carboncow** » 06 May 2014, 21:55

Interesting...I wonder if the elec vac pump is the random sound I heard every couple of months that sounds like something stuck on around the transmission. Where is that pumps location?

Post by **chrism** » 07 May 2014, 08:17

My 03 V70 makes that buzzing noise - cycles ON 2 seconds / OFF approx 8-10 seconds. It goes through this routine for a few minutes after shutting the engine off. Does it do this in order to support brake booster vacuum in the case of the engine dying while still rolling? How much should I hear it run before I say to myself "There must be a major vacuum leak somewhere?" Does this also involve the evap control system?

BTW - sometimes I hear the cycling buzzing after engine shutdown and sometimes I don't. I know I have a very minor (I THINK it's minor) vacuum leak at the backside of the brake booster around the shaft. 200K miles on the car.

carboncow · Post by **carboncow** » 07 May 2014, 11:17

I'm sure that is what mine is...but my wife and I rare occasion have heard this "thing" run for 20-30 minutes after the car is off...and I'm not talking about the evap blower that some models run to dry the AC evap!

I just replaced about every vac line related to the engine (not brakes) and I have no codes about minor/major air leaks...so who knows when and why it comes into play. I'm also at high mileage.

Post by **jimmy57** » 07 May 2014, 14:30

The vac pump is loud and should only run key on. Pump the brake with key on and it will start when vscuum depletes. The other buzzing is usually turbo control valve buzzing until ECM completes its shutdown routine.

Vac pump on P2 is on left frame rail forward and below air cleaner.

Post by **chrism** » 07 May 2014, 15:24

But my car is non-turbo and I still have the intermittent buzzing AFTER the key is turned off.