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Can an air pump issue cause problems elsewhere?

Hi everybody. I’m pretty new to auto repair, but I am relatively handy with plumbing and hardware, and am trying to learn more about auto work. Here’s my predicament:

My 2013 Chevy Equinox threw a check engine light about a month ago. I had it read at AutoZone, and it came up P0411 Improper Upstream Flow in Secondary Air Injection Pump. They suggested replacing the air pump, but multiple other opinions said it was likely a problem with the vacuum lines or bad sensors. When they all agreed that the problem was merely emissions-related and wouldn’t affect the car at all, I decided I would take care of it later.

However, recently the car has had some other problems. When in drive and stopped, the car sometimes starts to lunge, sort of like a bucking bull. When at speeds lower than about 35 mph, accelerating starts a whirring sound from what I think is the engine. Could these newer problems be related to the air pump issue? If so, is there anything I can do? Or should I just take it to a dealer and accept that I’m going to be writing a fat check?

Thanks in advance for any help you can provide!

The check valve may be leaking exhaust back to the pump. If so it will damage the pump and plumbing. Check for heat upstream from the valve.

The air pump might indeed be faulty, maybe one of its bearings is shot, and is now starting to bind up. Since it is driven by the engine, a binding air pump could result in an uneven load and cause the low speed bucking, as well as the whirring noise. If there’s a way to temporarily remove the air pump from the belt path as a test, that might prove diagnostic. There’s lots of other things that can cause bucking and whirring noises though.

Since you are trying to advance your auto repair diy’er skills, why not just replace the air pump yourself? Worse case, it won’t help with any of the symptoms but at least you’ll know how to do one more thing towards advancing your diy’er skills. An alternate , probably better, strategy might be to take your chevy to a shop that works on chevy’s and has the chevy scan tool and have them do a proper diagnosis, then you do the repair yourself.

The learning curve for repairing modern cars is pretty steep. Car repairs are not quite so easy to learn on your own by trial and error compared to diy’er plumbing and basic hardware. You’ll do yourself a big favor and save a lot of time and money to obtain access to the factory service manual for your car, or at least a Chilton or Haynes and reading the procedure first, before pulling out any wrenches. Googling will often show where you can get a used factory service manual, or one on CD rom. If you surf over to rock auto and bring up your car, there is usually a “literature” section in the list with service manuals. Suggest to review Popular Mechanics Complete Car Repair Manual as a way to get started in how modern cars work, as that makes it much easier to do a diagnosis. Maybe take a look at what it says about air pumps. Best of luck.

Good grief

OP has a check engine light

Autozone guys scan for codes and suggest the secondary air injection pump might be faulty

That’s not exactly the place for professional auto repairs . . . or diagnosis

The only thing that’s probably accurate is the code they retrieved. Anything else, I’d take with a grain of salt

Come on db, the guy said he wasn’t a mechanic so of course he wouldn’t have his own scanner. I’ve been wrenching for 40 years but never had the occasion to work on that year Eq. I just did a motor change on an 05 and ran into some things I didn’t know that costed me a bunch of time. Forums are for help to people who don’t know the answer. How they’ve devolved into snide comments I don’t quite understand. I wish I could help the OP, but I didn’t know they had a belt driven air pump on them. I can say this, as rule of thumb a code trips when a sensor reads something out of whack, often it’s a sensor or solenoid etc. but can be something mechanical causing the said sensor etc to trip a code. Again, I’ve not run into this so I can give direct advice, other than to ignore the snide comments and keep asking questions to you find someone willing to help.

Good luck,


Also, don’t put all your eggs in one basket, subscribe to as many forums as you can keep track of because many will not have people that know how to work on them or, people who just want to make insults. I’ve found there’s usually one guy at the parts store that’s actually a better mechanic than any of use ever will be. At one of the chains near me there’s a guy who’s kind of a strange encyclopedia and almost always as useful information. The dealership will rarely get you anywhere other than broke. Guys that like that work for themselves in their workshops are often your best bet if you know them to be honest. I don’t know the answer but would be able to find it because I have a lot of informational resources. Again, Good luck.

Telling somebody to take autozone’s advice with a grain of salt is not “snide”

As I said, he knows what fault code he has

I wouldn’t necessarily assume the secondary air injection pump itself is bad, at least not at this point

I AM helping OP. I told him to not accept autozone’s recommendations as the gospel truth

This is the internet, as you said

And comments will invariably not be pleasing to everybody. I know that sometimes people don’t like my comments. Such is life, as my father used to say. For that matter, don’t assume that all of your comments will always be well-received by all, either

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DB was not making snide remarks to the person who started this thread. He made the accurate point that the codes from a parts house are fine, just don’t expect real mechanical advice.

No snide remarks on a forum? Where is the fun in that.


db, I wasn’t trying to start a fight with you. And yes, the guys at auto zone OFTEN are morons that couldn’t put air in their tires, BUT, there are aslo often people that were great at diagnostics but too slow at repairs to make it as a pro. I’m one of them. My choices are either to work for myself or flip parts at the stores. I have the shop, tools and many years of experience but am too crippled up to be able to make money working on commission working for someone else. But, come on, your reply did come across as kind of condescending I’m sure you’d agree if you looked at it with the shoe on the other foot. If I offended, I am sorry, but that’s how I took it and I’m guessing so did the OP.

I profoundly disagree with that

Let’s just go our separate ways, so to speak

Goodbye, and take care of yourself

You have made a blanket statement that I don’t agree with. There can be problems that a dealer can solve that an independent mechanic has never seen.

Db, sorry if I took what you said wrong. That is entirely possible. Again, apologies if I took it wrong.

volvo, Correct, they’ll usually milk the hell out of you in the process but yes, they make have info or diag equipment the average shop does not. Most of the time they’ll just make ya broke but I did recently run into an issue on a buddies car I couldn’t sort out but I only use an inexpensive handheld scanner like they use at the stores and it didn’t show me the problem. The dealer found it right away but it was very expensive. Thanks to all and sorry if I came across as a “jerk”. LOL.

There , I fixed it for you. Our esteemed moderator ( Carolyn ) does not care for off color language so please edit your post.

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Ahh, true, I hadn’t even thought about that…sorry, it won’t happen again.

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There are a few Equinox specific forums that I found when I did that 05 recently. It took quite a few days to get the needed info which often doesn’t work well when you’re in the middle of a job but by chance one guy suggested another site that did have what I needed on it. My issue was decoding the block numbers because the 05 can only use motors out of an 05 or 06…period, no exceptions unless you change the harness, pcm and even then the other modules may not play nice together. In your case, it might help a lot.