Secondary Air Pump

[ashenator]

Last night I started my car but had to run back in the office. As I walked past my car I heard a fan running. Very odd...only had the car running for two minutes and it was 46-degrees outside. When I came back out to get in the car again the fan noise was still running. I checked under the hood and found the secondary air pump was running...for no reason. I have also noticed much poorer gas mileage lately...not sure if that is why. So I drove home and my headlights dimmed every 35-seconds as this air pump turned on and off. When I got home and took the key out it continued every 35 seconds...a warm up wind up and other times it would run for many minutes. I had to unplug the air pump in fear of it draining my battery. I am so gald I caught this early. The next morning I plugged it back in and no problems. I pulled out the relays and checked them on the meter and put them back in. I could not reproduce the problem. The dealership said they had never heard of this. I don't know if relays reset but I will keep you posted...maybe that is what happened when I unplugged it last night. Oh, I just installed a new Mass Air Meter last week too and reset my code. Another person on another site had the same exact thing happen. Very strange. THEN I happened to notice this morning that both my cooling fans appear to be inop. So I will be trouble shooting that. I am so grateful for this forum.

[speedie]

I know this is posted under the 2.0 forum, but is your car a 2.0?

1.8t have an after-run coolant pump that runs for 10 mins each time the engine is cranked regardless of temperature and engine run time.

Your SAP should come on briefly shortly after start-up and then periodically during stop-and-go traffic. The pump has a loud whirring noise likea vacuum cleaner.

[from Margaritaville...]

I just got my 2.0 back from the dealer on Tuesday. I had asked the service advisor (my friend and neighbor) to let me know the source of the recent constant whirring that would follow the rpm's of the engine. I was told that it was the secondary pump and that nothing would come of it (basically: just live with it). I asked what it would cost to rid myself of this sound. He said "You don't want to know...".

mine doesn't stop running...

[ashenator]

Thanks. I have a 2.0 engine. My question now is that none of my cooling fans run unless I turn on the AC. They both come right on...but turn it off and they both stop. I can get off the highway after driving for 40-min and pop the hood before I shut it off and the fans are not spinning. I wonder how much this is going to cost? Is this the relay or the little black box/computer?

[ashenator]

Originally Posted by Alan Margosian

I just got my 2.0 back from the dealer on Tuesday. I had asked the service advisor (my friend and neighbor) to let me know the source of the recent constant whirring that would follow the rpm's of the engine. I was told that it was the secondary pump and that nothing would come of it (basically: just live with it). I asked what it would cost to rid myself of this sound. He said "You don't want to know...".

mine doesn't stop running...

I just got mine out of the dealership last week too with a $1200 price tag. Are you sure it is the SAP or is more like a tapping or clicking sound that goes up and down with RPM? Also does it sound like it is coming from the passenger side engine compartment?

[btb]

BOTH cooling fans work when:
-Coolant temp is above 95C for low speed/102C for high speed, regardless of ignition
-A/C is in use (low speed)

If the air pump is acting up, just unplug it. No harm done whatsoever.

[from Margaritaville...]

Originally Posted by ashenator

...Are you sure it is the SAP or is more like a tapping or clicking sound that goes up and down with RPM?...

Not a tapping but rather a muffled whining sound. Sort of like a shot bearing or something...

[ashenator]

Thanks.

[Diognes56]

What did this end up being? My sister just got a '98 2.0L (not even a month ago), and she is having what sounds to be the same problem.

It sounds like the a fan (except they are not moving) or the secondary air pump is running after the car is shut off. It will kick on randomly while she is driving which I expect is normal for the secondary air pump, but whatever it is will also kick on randomly after the car is shut off (sometimes it will shut off when she shuts off the car and it will start up later) untill the battery is completely drained. Not really familiar with VWs, and I have only had the chance to look at the car once, but the noise (it vibrates too) is coming from the black canister on the drivers side of the engine (it has a hose running from it to the air intake and a couple other places). I am going to have plenty of time to look at it tomorrow and I wanted to get some more ideas about what to look at. Thanks.

David

[tgobble]

My secondary air pump on my '98 New Beetle makes that horrible screeching sound. If I simply unplug the damn thing will it cause my car to fail Atlanta, GA's emission test? Its just embarassing on start-up! I also had been told that VW had acknowledged a problem with the design of these pumps which is causing the valves at the top of the hose to stick open. This supposedly allows condensation to drip down the tube filling the pump with moisture. This causes the motor inside the pump to corrode eventually causing the high pitched whine/screech. I was once told that VW had formally acknowledged the problem and were working on a solution. Any chance this might indicate an eventual recall if its true? I've been pretty lucky I guess. Mine has actually been a great little car. It's 14 yrs old and this is the first problem I've had. Of course now the driver's side window broke. It's stuck in the fully down position (I have to get that fixed) and now my A/c just stopped! It was working fine with zero problems. I moved the car, turned the a/c off, and shut off the ignition. I changed my mind about where I wanted to park and started the car back up. I tried to turn the a/c back on and nothing. Absolutely nothing happens. Its actually no heat, no defrost, and no a/c. I thought it was just going to be a fuse but I have checked and tried changing all the obvious possibilities. Does anyone know if this might be a relay switch? Still even though this has all happened right here together I guess I shouldn't complain. The car still drives and rides great, it looks great, and being a five speed I've always thought it was pretty fun to drive. The only other work I've had to do to it were the couple of recalls that VW issued early on and then the brake light switch a few yrs ago. Always at VW's cost and always fixed right in one shot.

[Critter]

does anyone know where i can find my secondary air pump? I just got code p1421 and it says that the circuit is shorted to ground. No fuses blown so i don't think that there is a short, just a problem with the pump or the valve.

[simonsi]

Originally Posted by btb

BOTH cooling fans work when:
-Coolant temp is above 95C for low speed/102C for high speed, regardless of ignition
-A/C is in use (low speed)

If the air pump is acting up, just unplug it. No harm done whatsoever.

The radiator fans are triggered by coolant temp in the rad though, not at the CTS in the engine.

[geniushanbiao]

The secondary air pump runs depending on the signal of the coolant temperature. If the coolant temperature is below a certain point(I think it's probably around 60C) the pump runs to blow air into exhaust to reduce emission. So if you have the equipment you can hook your laptop with a VAG-COM cable to your car and monitor the coolant temperature. Then you can find out what's the problem.

Originally Posted by ashenator

Last night I started my car but had to run back in the office. As I walked past my car I heard a fan running. Very odd...only had the car running for two minutes and it was 46-degrees outside. When I came back out to get in the car again the fan noise was still running. I checked under the hood and found the secondary air pump was running...for no reason. I have also noticed much poorer gas mileage lately...not sure if that is why. So I drove home and my headlights dimmed every 35-seconds as this air pump turned on and off. When I got home and took the key out it continued every 35 seconds...a warm up wind up and other times it would run for many minutes. I had to unplug the air pump in fear of it draining my battery. I am so gald I caught this early. The next morning I plugged it back in and no problems. I pulled out the relays and checked them on the meter and put them back in. I could not reproduce the problem. The dealership said they had never heard of this. I don't know if relays reset but I will keep you posted...maybe that is what happened when I unplugged it last night. Oh, I just installed a new Mass Air Meter last week too and reset my code. Another person on another site had the same exact thing happen. Very strange. THEN I happened to notice this morning that both my cooling fans appear to be inop. So I will be trouble shooting that. I am so grateful for this forum.