I was wondering if there was still anyone on here having the mentioned problems.

Coming to a stop the car dies or the rpms fluctuate up and down a lot, or stay low sometimes even stay high. It does all this intermittently and the rest of the time the car runs fine. Despite all the fluctuations, it never throws a code.

I'm interested in finding people with the same problem, or people who have tried to fix it with the solutions mentioned on this board, changing the ignition coil packs, IAT sensor or anything like that.

Let me know what you've tried and if you are still having problems.

I think we can figure this thing out and it doesn't cost a lot.

Welcome to AF!

Sounds like the IAC valve is sticking and the PCM is unable to control the idle speed as it should. I think it's on the left side of the throttle body as you stand in front of the car looking under the hood, I've had a supercharger on mine for a while, and to be entirely honest, I forget how the TB is reoriented with it :). Most likely it's just carboned up, and can be cleaned off with throttle body cleaner and reinstalled. You should at least clean out the throttle body, but the engine would benefit from an induction flush if it has got to the point where the IAC gets plugged up. You may also be using low quality gasoline which makes deposits even worse.

Welcome to AF!

Sounds like the IAC valve is sticking and the PCM is unable to control the idle speed as it should. I think it's on the left side of the throttle body as you stand in front of the car looking under the hood, I've had a supercharger on mine for a while, and to be entirely honest, I forget how the TB is reoriented with it :). Most likely it's just carboned up, and can be cleaned off with throttle body cleaner and reinstalled. You should at least clean out the throttle body, but the engine would benefit from an induction flush if it has got to the point where the IAC gets plugged up. You may also be using low quality gasoline which makes deposits even worse.

That's is what I did, if what you are calling the IAC valve the butterfly were the throttle cable goes to. I cleaned that and lubed up the throttle cable springs and it's been working for two months. Mine had a lot of dust built up on the outside. I was just trying to find people that had the same problem to see if it would help them out any. I know these intermittent problems are a pain to find soemtimes. I kept reading at various places about people changing the ignition and all that. I was hoping to save some people some money.

It's nice to know I can go somewhere and get an answer like that though, that's pretty rare.

If I'm wrong about what I'm talking about, mine is on the right side where it comes from the air cleaner to the engine. If I have the wrong thing let me know and I'll go ahead and clean it also. I'm talking about the valve or butterfly that regulates the airflow by way of the throttle cable.

Any other common problems I should be on the lookout for ?

The only other problems I've had was the broken temperature control and the clutch cable sliced in half because of where they mounted it, what a bad place. I spliced it back together with steel brake line so rubbing shouldn't be a problem anymore.

How well did you like the supercharger ? what kind was it ? I've thought about getting one.

That's is what I did, if what you are calling the IAC valve the butterfly were the throttle cable goes to.

Any other common problems I should be on the lookout for ?

How well did you like the supercharger ? what kind was it ? I've thought about getting one.

Nope, that's the throttle lever/butterfly. The Idle Air Control valve (or motor or solenoid) is screwed onto the side of the throttle body and allows the PCM to control the airflow a little bit to get the idle exactly where it should be. It has 5 wires (I think) and probably one of those "safety" clips on the connector that you have to pull out to press the release in. It's held on with a T20 Torx screw, +/- a couple sizes. I'm 99% sure it's 1 screw, but it's very possible there's 2 if you get in there and find nothing with 1 screw in it.

The only really common problem is the wheel bearings. You'll hear them howling long before they fall apart, but if you drive on the highway or care about gas mileage much, replace them as soon as they start to make any noise or get loose at all. I just replaced both my rear ones when I aligned it because you have to use shims for the rear (solid axle) and I wanted it dead-on. One would make a very quiet hum on fast, sharp turns so I wasn't too worried about it, on the last oil change I did they were both still tight, but when I tried to align it, I noticed the camber and toe changing slightly when I raised/lowered the rack, so I checked them out really good, and sure enough they were very slightly loose. I got an increase of 4 MPG replacing them. A lot of people say the strut mounts are common, but mine are ok (85k miles), they creak a bit going into a steep driveway or flying around a corner, which I don't think is all that bad. And I have not yet seen one with bad mounts in the 5 years I've been an automotive technician, at least not bad enough for the owner to mention it.

I love the supercharger, definitely a worth-while upgrade. I got one of the very last GM Performance Parts superchargers, they discontinued it for some reason. If you're serious about getting some sort of boost, just ask in the Performance forum!

Nope, that's the throttle lever/butterfly. The Idle Air Control valve (or motor or solenoid) is screwed onto the side of the throttle body and allows the PCM to control the airflow a little bit to get the idle exactly where it should be. It has 5 wires (I think) and probably one of those "safety" clips on the connector that you have to pull out to press the release in. It's held on with a T20 Torx screw, +/- a couple sizes. I'm 99% sure it's 1 screw, but it's very possible there's 2 if you get in there and find nothing with 1 screw in it.

The only really common problem is the wheel bearings. You'll hear them howling long before they fall apart, but if you drive on the highway or care about gas mileage much, replace them as soon as they start to make any noise or get loose at all. I just replaced both my rear ones when I aligned it because you have to use shims for the rear (solid axle) and I wanted it dead-on. One would make a very quiet hum on fast, sharp turns so I wasn't too worried about it, on the last oil change I did they were both still tight, but when I tried to align it, I noticed the camber and toe changing slightly when I raised/lowered the rack, so I checked them out really good, and sure enough they were very slightly loose. I got an increase of 4 MPG replacing them. A lot of people say the strut mounts are common, but mine are ok (85k miles), they creak a bit going into a steep driveway or flying around a corner, which I don't think is all that bad. And I have not yet seen one with bad mounts in the 5 years I've been an automotive technician, at least not bad enough for the owner to mention it.

I love the supercharger, definitely a worth-while upgrade. I got one of the very last GM Performance Parts superchargers, they discontinued it for some reason. If you're serious about getting some sort of boost, just ask in the Performance forum!


Thanks for the help, I'll check out the IAC valve and clean it, just in case.

Are the wheel bearings pressed in or can you just pop them in and out. You suggest taking it somewhere for the rear ones ? I don't have access to a rack.

When I was looking I walked into a couple dealerships garages and asked the guys working on the cars what they thought, and they said they usually don't get cavaliers in that much and the biggest thing they saw was the brakes wear out quicker than other cars. I can live with that. It's been a good car so far, I think I have around 85K on it now. Hope it holds together I usually drive a car till it's on it's last leg. I got 285K out of a ford tempo. The guy I bought it off of said it was the only car he'd ever owned that didn't leave hime stranded, he had several new luxury cars in the garage, he had to get rid of it because he was too embarressed to drive it in his upscale neighborhood. It never left me stranded either but I was driving it alot of miles a day so I changed the fuel pump a couple times, the ignition, belts and all that before it ever went bad. I figure it was better to do it in the sunshine when I wanted to than alongside the road or in the winter and didn't have a choice. People look at you funny when you replace things before they go bad. I know things break and staying ahead of it I thought was better.

What kind of boost did you get from the turbo, 8 pounds ? Seems like a good engine just wondered how far you can push them. whether you can just add the turbo with low boost or whether you need to change the some sensors or injectors. What else needs changed ? I can probably get a small turbo and fabricate the mounting myself but it's always nice to have a kit with everything proven in it.

Ok one more question, IAC, I should just pull it out and clean it ? Should I just replace it ? Should I try to clean it from inside the throttle body if that's even possible. Just don't want to add extra problems to the situation.

Thanks for the help, I'll check out the IAC valve and clean it, just in case.

Are the wheel bearings pressed in or can you just pop them in and out. You suggest taking it somewhere for the rear ones ? I don't have access to a rack.

When I was looking I walked into a couple dealerships garages and asked the guys working on the cars what they thought, and they said they usually don't get cavaliers in that much and the biggest thing they saw was the brakes wear out quicker than other cars.

The wheel bearings come as "hub assemblies", and are incredibly easy to change on the rear. All you need is jack stands, a floor jack, 19mm socket (the emergency tire iron in the trunk is fine), T-45 (or so) socket, 15mm wrench, a 6" extension, and a ratchet for the before mentioned sockets/extension. Just put the rear up on jack stands, remove the drum, and loosen the 4 bolts that go through. Tap on the back of the bearing to get it broken free of the rust while you still have a bolt or two in there to hold it, then remove them completely. If you just let the backing plate fall it will tear the brake line off, or at least bend it much more than it should be bent. The fronts are a bit harder, just because of a large nut that is hard to turn without an impact. I only had it on the rack because I was aligning it, I wouldn't have even noticed they were loose if I didn't have the alignment machine sensors on the wheels, they would move about .2 degrees when I started and stopped the lowering/raising of the rack. I check them all every time I change the oil, and didn't notice anything 3k miles ago. Hub assemblies are a bad way to go, almost every vehicle that has them has them go out very frequently. I don't know why they didn't design them to be greased... Oh, wait, yes I do... they can sell more if they go bad a lot :rolleyes: Don't replace them before they're bad, it's not a safety issue and it won't leave you stranded anywhere. When one gets loose or starts making noise, replace it, but not before then. I have seen some that were so bad the car would actually shake because of the bearing, almost like the ABS was kicking in very softly all the time, not to mention the NOISE, eventually it would get bad enough that the stock radio wouldn't go loud enough to drown it out. Oh, and one more thing, on the rear hub assemblies, there may be a shim between the backing plate and the axle, if there is be sure to reinstall it in the same position as it was. This is how the alignment is done on the rear. If it falls out before you see which side goes in/out, leave it out. Installing it backwards will make it twice as bad as not having it in there.

I agree that Cavaliers are great cars. There are tons of them on the road, yet I get one at work maybe once a month. Usually nothing too serious on them. And if they do break, parts are dirt cheap.

What kind of boost did you get from the turbo, 8 pounds ? Seems like a good engine just wondered how far you can push them. whether you can just add the turbo with low boost or whether you need to change the some sensors or injectors. What else needs changed ? I can probably get a small turbo and fabricate the mounting myself but it's always nice to have a kit with everything proven in it.

Supercharger, not turbo. A turbo is a turbine that spins from the exhaust flowing past it which spins a second turbine that pressurizes the air. A supercharger is driven by the serpentine belt. Look up both on howstuffworks.com, that will give some good basic knowledge. And I have 14-15 PSI boost at full throttle, increased from the kit boost of 12 PSI by changing to a 2.9" pulley in place of the 3.3" that comes with the kit. You can't add any boost without reprogramming the PCM, or at least not enough boost that you could feel the difference. The stock Manifold Absolute Pressure sensor has no idea what pressure is, it only knows vacuum. Same for the PCM. You will need to change the injectors as well, the stock ones won't flow enough fuel for boost.

Ok one more question, IAC, I should just pull it out and clean it ? Should I just replace it ? Should I try to clean it from inside the throttle body if that's even possible. Just don't want to add extra problems to the situation.

Pull it out, clean it, spray out the passage it goes into, and put it back together. Since it works fine sometimes, the IAC solenoid is probably fine, just sticking sometimes. They don't have much power, and it doesn't take much to make them stick.

Thanks for all the advice, hope you're around if something really difficult pops up. I do know the difference between a turbo and a supercharger, I just have a turbo apart on my work bench got my train of thought mixed up.

I don't have any problems with the front axle nuts anymore, I have a big long steel pipe and I can break them free with 2 fingers, I just get worried about over torquing them when I put it all back together, I think I might have just used an impact and then just added an 1/8 of a turn or so last time I had to take one off. I remember one time I had some that were rusty and I didn't have the pipe yet and the impact wasn't strong enough, I ended up putting the socket and wrench on it, jacking up the car by means of the wrench and jumping on the hood to get the darn thing to break free. It finally did, I figure the wrench would have broke first but it didn't. You are correct those things are on there tight.

Once again thanks for the help. I'm going to copy all this stuff for future reference, except I will clean IAC out in the next couple weeks.

You're very welcome. I'll probably still be here.

You may want to invest in a large torque wrench before you do another drive axle hub assembly, too much torque will wear the bearing out prematurely. The spec, I believe, is less than 150 ft. lbs. (I need to look these things up :)), which you would be able to accomplish with a 2' bar quite easily. Too much torque puts too much pre-load on the bearing. I have seen people torque them to where their impact stopped (600 ft. lbs.) with no problems, but I always use a torque wrench just to be safe, nothing I hate more than doing the same job twice... and not getting paid the second time :2cents:

Thanks for your help once again.

The car started acting up again today so I went ahead and cleaned the IAC valve like you told me to. See if I have it right this time, it has two separate coils on it with a plunger coming out the center. Basically solenoid. It was right beside the TPS. It was on the passenger side just like you said, I was going to get the torx size for you but forgot to look. The plunger tip on the end did have deposits on it, a noticable amount not just a little bit you need a microscope to see. So I cleaned it pretty good and inside the throttle body as best I could. Took it for a drive and it works just fine, but it's an intermittent problem so we'll have to give it some time to know for sure. Seems like it runs smoother, and I'm not one of those guys that can feel extra horsepower after changing the air filter, but it could be in my head.

I'm amazed that everthing comes apart so easy, I saw the shroud and figure it was going to be a pain but all I had to do was remove a couple vacuum lines and loosen the hose clamp and it all came off. I didn't think they made cars you could work on anymore. I spent about a 1/2 hour on it, most of that was just cleaning.

Hopefully I got the right part this time and all is well. Thanks again for the help it is appreciated.

From your description of it, it sounds like that's the IAC you cleaned, hearing it jogged my memory. Usually cleaning it out will make the car run a bit smoother, especially cleaning the throttle body passage below it. Lets hope that does it, and you're welcome for the help.

I was wondering if there was still anyone on here having the mentioned problems.

Coming to a stop the car dies or the rpms fluctuate up and down a lot, or stay low sometimes even stay high. It does all this intermittently and the rest of the time the car runs fine. Despite all the fluctuations, it never throws a code.

I'm interested in finding people with the same problem, or people who have tried to fix it with the solutions mentioned on this board, changing the ignition coil packs, IAT sensor or anything like that.

Let me know what you've tried and if you are still having problems.

I think we can figure this thing out and it doesn't cost a lot.

My '97 Cav has had these same issues for well over a year now, and I'm still fighting it. The car runs fine, most of the time and gets 32 - 34 MPG. Mine does what you have described, plus stumbles on acceleration from a stop frequently. Here's the million dollar list of what I've replaced, non of which has solved the problems:
IAT sensor, EGR valve, MAF sensor, TPS switch, Crank sensor, Cam sensor, Fuel pressure reg, Fuel pump, Fuel filter, Fuel injectors, Coil packs, Plugs, Plug wires, Head gasket (head has been cleaned) as well as the entire intake system, throttle body and EGR passages, Air filter, Idle control solenoid, checked for vaccum leaks, PCV valve, Thermostat, Coolant temp switch, Cat convertor, forward 02 sensor plus I'm sure there are a few items I've forgotten about. Every now and then, the check engine light will come on, but usually goes off after a few minutes. Stored codes? usually a fuel rich or fuel lean, but nobody seems to know what it means. The car has been to the Chevy dealer twice and 4 other driveability shops, all which acknowledge the issues, but cannot pinpoint the cause.

I've tried to swap in another PCM for testing purposes, but cound not seem to reset the anti theft system, so the original PCM has been re-installed.
I'm hoping the car will die eventually and the problem will be evident. Until that happens, I'm stuck living with it as is, unless someone has the answer.

Even with the problems, it's still a Chevy, and as such, commands the utmost respect!
Thanks,