Various questions and comments about when a Porter Cable air compressor turns on but will not turn off.

Porter Cable C2002 model air compressor
Porter Cable C2002 model air compressor

Porter Cable concern – it turns on but won’t turn off

have a porter cable electric air compressor 150 psi, it turns on but won’t turn off when it’s suppose to and also when it’s running it sounds like it has something in it that rattles not sure if it’s in the motor. do you think you can help me?

When you say that it won’t turn off, are you saying that it runs and won’t stop, and the pressure in the tank keeps rising, or are you saying that it runs non-stop, and the pressure in the tank gets to a certain level (what level?) and won’t go past that.

If the former, you likely need a new pressure switch.

If the pressure won’t rise, wander over to the TROUBLESHOOTING page and click the link to “won’t build pressure” for some tips.

Are you sure the rattle is inside the compressor, or something loose on the outside?

No PSI Porter Cable Pancake compressor

by Doug
(Laredo, Mexico)

Porter Cable 150 psi max
6 gallon tank
2 hp
2.6 scfm @ 90 psi

Purchased about two years ago, used about 6 or 7 times, mostly to dust out computer. Used nail gun once. Turns on just fine, fills tank with air and shuts off automatically when tank is full. Problem I have not getting any pressure to operate tool or the air gun. Shut off, bled tank, restarted with same issue.


You are not alone. I get questions about this issue often enough that I wrote a page or so on it.

Please go to the TROUBLESHOOTING PAGE on this site and look for “no air out of hose” for some tips. Thanks.

Porter Cable Air compressor can’t supply rated CFM

by Steve

Porter Cable cpf23400s-2 doesn’t seem to supply the need cfm although pressure builds to 135psi … even with small draw (i.e., regulator spilling air to limit output to 90psi) the pump runs continuously and never gets to 135psi.

When I remove motor fan cover I can rotate the motor armature and piston cycles very easily … wonder if this is an indication that piston, sleeve and compression ring need to be replaced.

Steve, it’s possible it’s a pump issue. However, I think it more likely that you have a leaky intake valve or an internal gasket failure.

Can you feel air being taken in at the intake port? Is there any air puffing out? If so, your valve is wonky.

Otherwise, if it were my air compressor, and there were not leaks anywhere visible, I’d tear down the pump to check the gaskets.

Motor starts and stops, starts and stops – starts fine and fills the tank

by Matt Klann
(Atlanta, GA)

Hey Bill,
I have a Porter-Cable CPFAC2600P-1 150psi 6gal pancake air compressor. The motor starts fine and fills the tank to 50 or 60 psi (1.5-2 mins) and then shuts off.

A few seconds later it will come back on, run for a few seconds and then shut off again, it continues this start/stop cycle until I turn it off at the switch.

Porter Cable CPFAC2600P air compressor
Porter Cable CPFAC2600P air compressor

There doesn’t seem to be any drag to the motor when this happens, almost like it is hitting the pressure switch. I bypassed the pressure switch and the problem persisted.

Once I unhooked the compressor from the tank, the motor ran fine with no problems for over 10 minutes before I shut it off. But if I connect it to the tank, the problem comes back.

It is getting clean power directly to the compressor’s power cord and doesnt seem to be drawing any excessive amperage when I put my multimeter on it. Could this be an issue with the check valve or the motor itself since it works fine once its unhooked from the tank? Thanks!!! Matt


Excellent detail on the compressor problem Adam, thanks.

My first thought was pressure switch, but you dashed that by your bypassing of it and the fact that the problem persists.

I’m going to now guess that the motor is going into overload as the back pressure from the tank is increasing the load to it. It may be the motor is failing, it may be a capacitor issue.

If this were my compressor, I’d have the motor and capacitor(s) tested.

How do you stop (Porter Cable) air compressor from whistling?

by Tony Jimenez
(Chino, CA 91710)

Lately, air compressor is having delay issue at start and when its starts it’ll run okay along with a whistling sound…is that normal?

Have never done that before.

I checked filter and air hosed it out, checked oil looks okay. checked belt was a little loose removed guard grill and tighten belt a bit and its still whistling at start-up

How do you stop (Porter Cable)air compressor from whistling? Well Tony, I’m not sure. Maybe tape it’s mouth shut?? 🙂

What you aren’t telling me is where the whistling is coming from. Can you pinpoint a location?

Where on your compressor is the noise coming from?

It won’t start

by Marty
(Port Huron Mi)

I have a porter cable 150 PI pancake compressor. It’s about 2 years old and I have had no trouble with it until now. I shut it down for the winter, and opened then drain. I went to restart it this spring to blow off my lawn mower, and it won’t start. I have power where it’s plugged in because I checked that.

Marty, good that you checked for power. That’s step one.

Can you use a multi-meter to see if power is passing through the pressure switch to the motor? If not, with the unit plugged in, give the pressure switch a wrap on the bottom with a screw driver handle. Anything happen?

If not, is there any noise of any kind when you plug it in? If power isn’t getting to the motor, then, of course, it cannot start.

Post any response you have here please so I can keep track of who says what.

Do you have

a question about what to do when Porter Cable air compressor turns on but will not turn off? If so, use the form below to add it, and please upload lots of photos!