Home » Our Pontiac Aztek Has Been A Great Daily Driver Except For One Major Issue: Unintended Acceleration

Our Pontiac Aztek Has Been A Great Daily Driver Except For One Major Issue: Unintended Acceleration

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The Pontiac Aztek is a bit of a pop culture icon. Its polarizing looks — combined with its stardom in Breaking Bad — has led to a bit of a “Zero to Hero” transformation, with the Aztek eschewing its “nerd” title for a very clear spot at the jock’s table. Here’s what it’s been like daily-driving the thing.

I’ve already written a full, unironic review of the Pontiac Aztek, and now that I’ve been daily-driving the thing, I can tell you: That review is pretty much spot on. The Aztek is a lovely machine to drive every day. It really is just a four-door minivan with two rows and a tailgate. The driver sits up high like in a minivan, the ride feels minivan-esque, there’s an absurd amount of space inside, and handling is… uh, cumbersome in the corners but magic carpet-smooth on the straights.

Vidframe Min Top
Vidframe Min Bottom

Add the fact that the seats are amazing, the sound system is way better than you’d expect, and the visibility makes new cars feel like bunkers, and the result is an absolutely wonderful daily driver whose main downsides, really, are its ho-hum fuel economy and perhaps its lack of Bluetooth capability.

It still feels about a century older than my BMW i3S, but it’s still great.

 

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The power from the 3.4-liter V6 is plenty. 185 horsepower is really not bad, and though it’s held back by a four-speed automatic, zero to 60 times of 9 to 10 seconds are more than enough. I’m delighted every time I get behind the wheel of our extremely well-bought Aztek, though there is one thing that really holds it back. Here, allow me to let Mercedes explain the problem:

 

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The car wants to accelerate up to about 65 mph on a (flat) highway. All on its own.

This has been a problem since we first took ownership of this hideously-charming SUV, but it seems to have gotten worse, particularly when the engine is warm. The revs climb to the sky, overheating the transmission, causing it to upshift and downshift really hard.

I’m not worried about the brakes, which get a bit hot while slowing the car down on long downhills (Matt says they were smoking on Mulholland Drive), since those are easily replaceable — I’m worried about frying this transmission, so I’m going to have to get to the bottom of this high-idle issue. Usually I’d suspect an issue with the Idle Air Controller sensor, but given that this is only an issue when the engine is hot, I wonder if it might be something else. Perhaps a vacuum leak? (I checked this already, but I’ll try again). Or perhaps a mass airflow sensor issue? Or perhaps a coolant temperature sensor issue?

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If you have any suggestions, hit me in the comments. Because this lovely machine is pretty much perfect, except for that one rather significant issue, which I’d love to fix before I begin living in this in a week or so after my strained back heals up a bit.

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Cam.man67
Cam.man67
19 minutes ago

Just throwing this out there…I had a very similar issue on my ‘96 K1500 for about a year after I bought it. The truck idled at 1500rpm, which of course made it slam into gear. It would accelerate on its own to about 30-40mph on flat ground. I replaced every sensor (TPS, IAC, Crank pos., MAF, maybe the temp sensor too) I could think of with no change in symptoms. Never had check engine light either. After 4 trips to 3 different shops, I finally just told them to stop wasting my time and money replacing known-good sensors and to just replace the ECU. Dang if that didn’t fix all of my issues. Not sure if that’s what you’re dealing with here, but being a GM vehicle of relatively the same vintage, something to keep in mind.

Happyscrappy
Happyscrappy
39 minutes ago

I’m pretty sure one of the late 90s Grand Ams in the family stable had the same issue. If I remember correctly, we used to pop it in neutral and tap the gas pedal a time or two and it would drop back down to normal revs.

Rollin Hand
Rollin Hand
1 hour ago

For Pete’s sake check the codes. Reduce the guesswork.

My guesses: vacuum leak, idle air controller or…does it have a throttle position sensor?

Jack Trade
Jack Trade
1 hour ago

Can’t believe I’m the first to say it, but David, just turn the vehicle off when you want to sleep and then the noise won’t bother you.

Totally not a robot
Totally not a robot
2 hours ago

My Chrysler Pacifica of the same vintage had a similar issue with unintended high revving. I eventually resorted to putting it in park at all stop lights.

It was traced back to the alternator spitting out alternating current at times, which was actually a relatively common issue with that car. I’m guessing the AC fried some of the ECUs because that car had several electrical gremlins that caused it to throw random codes and fail smog.

Motorhead Mike
Motorhead Mike
2 hours ago

I suppose, if you’re trying to, smoking brakes on Mulholland would be a badge of honor, but in your case…

Anyway, being 20-iah years old, the vacuum leak or MAF sound like a place to start. That said, when I took my old 525it for a test drive, it started doing something like that. The accelerator cable housing had come out of the barrel adjuster, on the throttle body, and got stuck on the upper edge. (I’d have to draw you a picture…) Take a look and make sure that all of the mechanical bits are seated correctly.

Adrian Clarke
Adrian Clarke
2 hours ago

Well, well well. Serves you right for not buying the black one I found.

Urban Runabout
Urban Runabout
3 hours ago

I bet it’s a floormat issue.

And what on earth are you doing up on Mulholland in an Aztek?
That’s exactly not the road for it.

Pico – That’s the road for an Aztek.

Mercedes Streeter
Mercedes Streeter
2 hours ago
Reply to  Urban Runabout

The gas pedal is in the resting position while all of this is happening!

Urban Runabout
Urban Runabout
1 hour ago

Oh dear – No Bueno!

Citrus
Citrus
3 hours ago

I feel like “it’s perfect except it’s always trying to kill me” indicates that it is not, in fact, perfect.

Last edited 3 hours ago by Citrus
Totally not a robot
Totally not a robot
2 hours ago
Reply to  Citrus

That’s kind of the baseline for all of David’s (Detroit style, not Hollywoodified) cars, though.

TDI_FTW
TDI_FTW
3 hours ago

I think I speak for everyone when I say you don’t get to count time in the shop towards your month of daily driving, even if it’s during the middle of your “month”.

Mercedes Streeter
Mercedes Streeter
3 hours ago

I’m not sure why I found the Aztek’s revving problem to be so hilarious, but I couldn’t stop laughing at it. Maybe it was the fact that I had to put it in neutral just to maintain 30 mph and each time I stopped at a red light poor pedestrians thought I was insane for just revving the thing out.

I lost count of how many times I said, “I swear it’s not me!” That probably didn’t help. 😀

Jack Trade
Jack Trade
1 hour ago

What was driving it actually like? Did you peel out at every light when you put back it in D?

Mercedes Streeter
Mercedes Streeter
1 hour ago
Reply to  Jack Trade

I wish! Instead, it just neutral-dropped, shuddered, and began accelerating on its own. There were times I had to hold the brakes because the car in front wasn’t accelerating fast enough! LOL

It also did 55 mph without any throttle input. In the longer version of the video I joked I had cruise control at all times.

As a side note, I sometimes pulled over to see if I could fix the situation without any tools. A lot of youngins took pictures of the Aztek. Have we reached the point where seeing an Aztek is special?

GENERIC_NAME
GENERIC_NAME
3 hours ago

I don’t think I’ve ever heard anyone sounding so gleeful about being murdered by a cheap crossover.

My guess would be the idle air control valve – I think it will have one, and they’re usually cheap and near the top of the engine so it’s an easy one to fire the parts cannon at. They get gunked up with engine oil and get stuck in one position, and if it was stuck open it would cause a high idle.

My old Ford Fiesta had one go bad in the other direction so it would stall whenever I put the clutch in while slowing down. It’s why I now know how to heel and toe.

Crank Shaft
Crank Shaft
3 hours ago

I’m firmly on the vacuum leak or mass airflow sensor. As Abdominal asked, what codes is it throwing? The SES is lit up, so there must be some.

Paul B
Paul B
3 hours ago

Does it have a throttle cable? I’d look at the mechanical cruise control.

1978fiatspyderfan
1978fiatspyderfan
3 hours ago

I had a similar issue. Turns out after getting in and out the floor mat would slowly advance until the tip was hitting the back of the accelerator pedal and reacted like pressing the gas. I also helped a caller on Click and Click with this diagnosis.

Abdominal Snoman
Abdominal Snoman
4 hours ago

Yeah, I suspect vacuum leaks, but being as you’re at Galpin, I’m sure you can get your hands on a good OBD2 diagnostic tool that can read out the values of every sensor and try activating various solenoids and motors. I’d double check basics first such as throttle position matches the actual pedal, intake air temp is right, long term fuel trims are reasonable, etc. just to rule out a bad sensor.

Speedway Sammy
Speedway Sammy
2 hours ago

You speak much wisdom.

Rippstik
Rippstik
4 hours ago

Sounds a lot like a vacuum leak. I replaced the intake manifold on a fix and flip duratec Mazda6 and (foolishly) skipped replacing the gaskets. Thing started and revved wayyy up. I put it in drive and it squealed the tires in my garage. Replaced the intake manifold gaskets and the issue was fixed. It’s an older GM that was in AZ. Something tells me some gaskets got baked or some vacuum hoses split.

Either way, I can’t imagine that firing the parts cannon at this Aztek will be incredibly expensive, because GM (and junkyards).

Last edited 4 hours ago by Rippstik
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