Car Guys! Help?

[youcancallmeclaire]

Hiya, I don't belong to any other forums where I could ask this kind of question, so I thought I would ask here.

About a week ago, my check engine light came on and I can't figure out what's wrong. My car is a 96 Chevy Cavalier Sedan, 4cyl.

I checked the oil, brake fluid, power steering fluid, and coolant and refilled whatever was low. I don't really know what to check other than that. Nothing feel physically wrong with the car when I'm driving. It runs the same as it always does.

What else could trigger the check engine light?

And please don't tell me to take it to a mechanic, because I can't afford one. I just want to try and remedy this myself before it causes something major to go wrong.

Also, I am semi-competent when it comes to automotive stuff, so please don't reply as if I'm an idiot. I just need some suggestions is all; I can't think of anything right now.

<3 claire

[Wombat]

It could be anelectrical fault. A short somewhere may be causig the light to come on. I say that because you have said that you have checked all the fluid levels and nothing seems to be wrong with the 'feel' of the car.

I had a problem with an older car that I owned where the engine overheat light kept coming on. It turned out to be a loose wire touching on the engine block causing the light to come on. I chased that problem for ages.

[TomSelis]

Could be a sensor.

[Riddler]

its the cars ecm (computer) sensing there is a fault. one easy thing to check is the gas cap. that will make the light come on if you dont replace it. You can bring it to AUTOZONE they check the "check engine light" for free and tell you waht code comes up.

they use a tool like this called a code reader

http://www.harborfreight.com/cpi/photos/94100-94199/94169.gif

[MacShreach]

Also, I am semi-competent when it comes to automotive stuff, so please don't reply as if I'm an idiot. I just need some suggestions is all; I can't think of anything right now.

<3 claire

Hi claire

I'm not familiar with that model but in general terms a check engine light can be triggered by any of the items you mentioned but also by mileage-- for example if the routine oil change/other service period is overdue. This is pre-programmed into the engine management unit.


However there are a whole range of other things that could cause this, depending on how your car displays its warnings-- lambda sensor, cat, fuelling, EGR system, EGR canister, breathing system, the list goes on and on and without being able to plug into a diagnostic unit it's hellish difficult to identify the fault.

Many of these faults will not affect the running (or stopping) of the car, but faults in the emissions control system could get you a fine if you fail a roadside check (if these happen where you are.)

Personally I would do a basic service-- change oil and air filters, change oil, plugs, check HT, clean engine breather, that stuff, before going further.

It really depends on the car but you may need specialist equipment to reset the EMU to clear the signal. (After doing the service.) Sometimes however there's a user-accessible method, like for example, disconnect the battery leads for 2 mins and then reconnect-- this works for quite a few models and resets everything to default.

Sorry not to be more help (now if you were driving a Jag, it would be different LOL) but just try Google before you go any further-- I'll bet there's a support board for that car somewhere.

Good Luck

[MacShreach]

. You can bring it to AUTOZONE they check the "check engine light" for free and tell you waht code comes up.


That is an extremely good idea.

[youcancallmeclaire]

. You can bring it to AUTOZONE they check the "check engine light" for free and tell you waht code comes up.


I didn't know they offered such a thing. Thanks alot!

I kinda wish I had one of those diagnostic car-computer interface things. That seems like it would be interesting. :)


...and now that I think about it, I do belong to a Cavalier forum, but I haven't logged in for like a year or two. :?

Thanks for all the suggestions from everyone else! :) :)

[brickcitybrother]

Since your Car is a 96 it has an OBDII computer. Find out what Autozone says and double-check here http://www.obd-codes.com/trouble_codes/

[StaggerLee]

Autozone's scan tools are kind of vague...I deal with them every day, and they sell a lot of people a lot of parts they don't need-they will give you a code, but you can be chasing a problem forever. From my experience with the cavaliers, I would guess at an oxegyn sensor...the car runs fine, but the sensor has failed, and sends a bad signal, causing the 'check engine' light. But the fuel cap is a good place to start, too...hopefully it's just that simple-good luck!

[rabidroyboy]

I think it is an 02 sensor (oxygen sensor).

That is the most common problem that trips a check engine light when the car otherwise preforms normally.

It is an emission problem. So you could drive forever and it's not not going to affect the performance of the car. The only problem is, you can't tell if another serious problem comes up because the light is already on.

Oxygen sensors are expensive. About 300 to fix.

As a previous poster noted, tighten the gas cap first, and see if that helps. But the gas cap thing is more common on newer cars.

How does the car's transmission shift? If the there is transmission problems, that will set off the check engine light, also. If it is a transmission problem, it is going to hurt.

Because your car is inexpensive, if it is a oxygen sensor, I wouldn't fix it.

Good luck with your car.

[sheer1]

These are some good and some very bad replies to your CEL(check engine light).I've been an auto tech for several decades and now specialize in "hot rods".
The first step is to have Autozone or some repair shop or dealer scan the ECM for fault codes.That will tell you what system is malfunctioning.A dealer or repair shop can give you much more detailed information than Autozone's generic code reader.
My educated guess without knowing the fault code would be that you could have a bad O2 sensor or malfunctioning catalytic converter.This could explain why your car still runs normal.As with anything,extended neglect could lead to more serious and detrimental problems.It could be something as simple as a loose gas cap.Do yourself a favor and have it scanned professionally.Otherwise we are all guessing.Good luck.

[hippifried]

Your car just needs a new owner.

Problem solved.

[scorpion]

Buy a german car...Audi or Porsche and I dont think you see this problems anymore :wink:

[Rod la Rod]

If the car is running good and there is no issue with passing an emissions test for licensing. Just fucking ignore it and keep driving this heap until it won't drive anymore. If you try to solve the mystery of the engine light you will waste a lot of money for no reason. Make sure you have oil, coolant, tranny fluid and clean air, fuel filters and forget about it.

If it can be licensed, and gets you around, just drive it and ignore the idiot light.

[OEMEnemyNum1]

Actually the most common problem is having your gas cap not tight. It will cause an evap leak, and that will throw a light.

[OEMEnemyNum1]

The Code is probably stored in a type of Keep Alive Memory, so you could clear it out with unplugging your batteries. If it comes back it's a consistent code, if it's gone then it could be an intermittent fault.

[sheer1]

Claire,
If it turns out to be an O2 sensor or converter,seek out a shop that does custom exhaust work.They'll be able to repair it relatively cheaper than the dealer/repair shop.(They can splice converters without replacing the whole pipe assembly).
If it is something you can DIY,you can turn off the CEL after repairs by disconnecting the negative cable off the battery for 20 minutes.

[OEMEnemyNum1]

Claire,
If it turns out to be an O2 sensor or converter,seek out a shop that does custom exhaust work.They'll be able to repair it relatively cheaper than the dealer/repair shop.(They can splice converters without replacing the whole pipe assembly).
If it is something you can DIY,you can turn off the CEL after repairs by disconnecting the negative cable off the battery for 20 minutes.

That will work only is the freeze data is stored in a keep alive memory, if it's in EEprom you're out of luck. Most older vehicles didn't have good eeprom so they would have chosen RAM. So she's probably safe.

Try that on a 2008 model domestic, and you wouldn't accomplish anything.

[sheer1]

Claire,
If it turns out to be an O2 sensor or converter,seek out a shop that does custom exhaust work.They'll be able to repair it relatively cheaper than the dealer/repair shop.(They can splice converters without replacing the whole pipe assembly).
If it is something you can DIY,you can turn off the CEL after repairs by disconnecting the negative cable off the battery for 20 minutes.

That will work only is the freeze data is stored in a keep alive memory, if it's in EEprom you're out of luck. Most older vehicles didn't have good eeprom so they would have chosen RAM. So she's probably safe.

Try that on a 2008 model domestic, and you wouldn't accomplish anything.The beauty of the OBDII systems is the fact that it self diagnoses every time with start up.Notice that you can turn off CELs AFTER repairs are made.If the CEL comes on again,repairs were not done correctly or there is another(multiple) fault codes.

[tsntx]

like it or not a mechanic can check the light and tell u the problem and that will be cheaper then permantly damaging ur vehicle.... u dont have to have the service done but at least ull know what u need to do to it -j

[miguel noche]

more than likely like the other posters have said it's a sensor and if it's running fine don't mess with it because it's a chevy and when chevyc get old they tend to break down alot i once had a corsica nad it wwas the biggest piece of junk ever

[Detroit]

If you put the gas cap on improperly the light will come on and will not reset until your car has been hooked up to a computer. If it drives OK then I think that the problem.

[youcancallmeclaire]

I think it is an 02 sensor (oxygen sensor).

That is the most common problem that trips a check engine light when the car otherwise preforms normally.

It is an emission problem. So you could drive forever and it's not not going to affect the performance of the car. The only problem is, you can't tell if another serious problem comes up because the light is already on.

Oxygen sensors are expensive. About 300 to fix.

As a previous poster noted, tighten the gas cap first, and see if that helps. But the gas cap thing is more common on newer cars.

How does the car's transmission shift? If the there is transmission problems, that will set off the check engine light, also. If it is a transmission problem, it is going to hurt.

Because your car is inexpensive, if it is a oxygen sensor, I wouldn't fix it.

Good luck with your car.

It's shifting fine and the gas cap is tight. (although the cap has been slightly broken for about 2 years, but never had any operational problems from it.)
One thing I noticed is that the heat seemed a little cooler than normal, but that could have been my imagination or the fact that it was reeeealy cold out today.

I don't know anything about oxy sensors... I'll have to go look that up.

[BeardedOne]

One thing I noticed is that the heat seemed a little cooler than normal, but that could have been my imagination or the fact that it was reeeealy cold out today.

Check your coolant/antifreeze level. While 'cool heat' could be a bad heater core, it is more often low coolant. Low coolant = Very bad.

[youcancallmeclaire]

Check your coolant/antifreeze level. While 'cool heat' could be a bad heater core, it is more often low coolant. Low coolant = Very bad.

Already did. It's fine.

I remember something like this happened on my other car... a spring-valve thingy mounted in the top of the radiator kept getting stuck open and I had no heat for one of the coldest NY winters in awhile.. I can't remember the name of the part though. :/

[youcancallmeclaire]

If you put the gas cap on improperly the light will come on and will not reset until your car has been hooked up to a computer. If it drives OK then I think that the problem.

I didn't know it wouldn't go off... my gf drove my car recently, maybe she didn't put it on correctly. :/

I think I remember reading somewhere that I can reset the engine light by taking out some fuses or something of the like.

[youcancallmeclaire]

more than likely like the other posters have said it's a sensor and if it's running fine don't mess with it because it's a chevy and when chevyc get old they tend to break down alot i once had a corsica nad it wwas the biggest piece of junk ever

I honestly don't remember needing a single thing replaced other than brake pads in about 40,000 miles.. It had 100k on it already when I got it.

[BeardedOne]

Ah, yah, remember the coldest days real well.

On the Lincolns and Caddys we just popped the thermostats out. Heat wasn't as hot as it could be, but they rarely overheated and you didn't have to worry about them sticking open or closed.

[youcancallmeclaire]

Ah, yah, remember the coldest days real well.

On the Lincolns and Caddys we just popped the thermostats out. Heat wasn't as hot as it could be, but they rarely overheated and you didn't have to worry about them sticking open or closed.

That's what it was! Thermostat.
The one on mine was riveted to the antifreeze cap... how did you pop them out?

[Sly Fox]

:!:

[BeardedOne]

That's what it was! Thermostat.

The one on mine was riveted to the antifreeze cap... how did you pop them out?

Interesting. I'd guess: New/Different cap.

On Lincolns (I drove stretch limos and sedans) and Caddys (The hearses, ambulances, and limousines), the thermostat was a seperate part, usually where the top radiator hose coupled to the block. You'd just remove it and tighten the clamps down a little more to allow for the difference in spacing.

The ones I'm used to (Lincolns from '89 - '92 and Caddys far older than that) were much simpler models. I'd actually have to get some hands-on with your model (The car, lady, the car!) to see what it's up to. Sometimes a hammer works as well as a screwdriver in these cases (Ya gotta break it to fix it).

<Thinking> What you're describing sounds more like a pressure release valve. Hit up a bookstore and find a Chilton's manual for your car and model year. Best damn decoder ever published.

[justatransgirl]

Claire:
Some good ideas from the guys.

Without getting too technical, with todays' cars you have to have a scan tool to diagnose most problem.

Check engine lights are primarily for emmission control monitoring the various sensors and when one goes out of parameter it sets a code and lights the CE light. As someone said mileage can trigger it too, though I don't remember if Chevy does this.

I may have missed it in someone's post. But the first thing you need to do since the gas cap is on right, is to read the code and reset it using a scan tool and see if it resets.

Sometimes it can be something as simple as having turned the car on and off real fast causing a flow of unburned fuel into the exhaust.

So check the simple stuff first.

I'm not familiar with the 96 Cavilier, but I had an 85 (OBDI) and the O2 sensors were constant trouble. But they weren't $300, more like $35. Unless they are doing something dumb with the 96 it ought to be able to just be unbolted and replaced.

So how does a t-girl know this stuff? My Chevy broke down on me and cost me $700 for a fuel pump (cause I got ripped off) so I decided to learn how the darn things work and got a college certificate in Auto Technology - most of which I've forgotten...

And now 10 years later, I'm such a lazy weenie and afraid I might break a nail, so I buy a new car every three years so I don't have to deal with repairs...

Giggle,
TS Jamie :-)

[ccg218]

cheap fix.... take your car to Advance Auto Parts or PepBoys and ask them to do an ENGINE DIAGNOSTIC SCAN....say those exact words....they will take a hand held reader out to your car, scan it and take you back inside...then they will print the list of what came out, and what you do is up to you next

[fhsjazztrumpet2]

My 97 Altima would have the check engine light go on and off as the car's OBD computer coded with emissions faults. I replaced the O2 sensor, but it had a leaky intake manifold gasket (which is apparently a problem after time on those cars). I didn't feel like replacing that, so I just left it alone.

It would turn on if I idled for a long time, but if I was driving normally, nothing. If it came on, five or six starts down the road it would turn off and things would be fine again.

[MacShreach]

Ah, yah, remember the coldest days real well.

On the Lincolns and Caddys we just popped the thermostats out. Heat wasn't as hot as it could be, but they rarely overheated and you didn't have to worry about them sticking open or closed.

That's what it was! Thermostat.
The one on mine was riveted to the antifreeze cap... how did you pop them out?

Claire, the item you are describing is NOT the stat but the coolant pressure relief valve. Don't screw around with that, they rarely if ever fail. The stat will be on the outlet side of the water pump under a cover (usually but not always domed), usually fixed with 2-3 bolts but WATCH IT because these bolts can get waisted (thinned) esp if you ever run with water rather than coolant (bad) and if you shear one off in the head you will have the mother's own job getting the end out. (Classic case of a £5 part causing a £1000 repair bill.) If they are studs (threaded bars with a nut on the end) use plenty of release oil, let it work overnight, and use a bit of heat if you have to.

Make sure you get a new gasket with the new stat BTW, the old one will be gubbed.

People used to pop out the stats, B1, but yer showing yer age there. Don't do it unless as a get-home for a car that's boiling up (stat jammed shut.) It was never a good idea, better was to remove the stat part itself and re-insert the restrictor plate. (The flow restriction is designed into the system.) The stat reduces engine warn-up time which is good for emissions and fuel but also reduces wear on the motor as it wears most quickly when cold. In the old days when everybody did 3000-mile oil changes this was less of an issue but nowadays with longer service intervals it's not to be recommended. Stats are very cheap, just replace it.

[memyself]

youcancallmeclaire have a look here, it might help.

o2 sensor info:
www.mr2.com/TEXT/O2_Sensor.html

gen info:
www.automotiveforums.com/f1504-cavalier_problem_diagnosis.html

[youcancallmeclaire]

People used to pop out the stats, B1, but yer showing yer age there. Don't do it unless as a get-home for a car that's boiling up (stat jammed shut.) It was never a good idea, better was to remove the stat part itself and re-insert the restrictor plate. (The flow restriction is designed into the system.) The stat reduces engine warn-up time which is good for emissions and fuel but also reduces wear on the motor as it wears most quickly when cold. In the old days when everybody did 3000-mile oil changes this was less of an issue but nowadays with longer service intervals it's not to be recommended. Stats are very cheap, just replace it.

That is exactly what happened on the other car. It kept getting jammed, and causing all sorts of terrible problems, boiling over and whatnot, and all it took to fix it was an $11 part.

[youcancallmeclaire]

I've actually been trying to figure out whether I can build some kind of OBD-II interface. :lol:
Even though I have found someplace to buy them for $30... shows how cheap (and geeky) I am..

[whatislove]

Some cheap people who have a bit of experience around cars drop the thermostat in water and heat it up... it opens up around 180 degrees. if it opens it's good.

Not to get too hippyish, but feel your car. Try to imagine the air in the tires, the way the brakes push back at you. The sound of the engine, vibrations, cornering all that leaves and impression on you.

When things change, you can 99% do a test that will give you all the info you need.

Like in your problem before... the temp guage is shooting through the roof... open the hood... is the fan on? is the rad. hot? fan is electric, controlled by a thermo switch and if the rad. is not even hot that means the thermostat isn't passing hot coolant through it. i.e. broke 'stat.





People used to pop out the stats, B1, but yer showing yer age there. Don't do it unless as a get-home for a car that's boiling up (stat jammed shut.) It was never a good idea, better was to remove the stat part itself and re-insert the restrictor plate. (The flow restriction is designed into the system.) The stat reduces engine warn-up time which is good for emissions and fuel but also reduces wear on the motor as it wears most quickly when cold. In the old days when everybody did 3000-mile oil changes this was less of an issue but nowadays with longer service intervals it's not to be recommended. Stats are very cheap, just replace it.

That is exactly what happened on the other car. It kept getting jammed, and causing all sorts of terrible problems, boiling over and whatnot, and all it took to fix it was an $11 part.

[2754tim]

Claire,
Check Your Fluids,Good Trick Is Pull The Fuses,Put Them Back In.Restart The Car.
Tim

[CORVETTEDUDE]

claire...I work at a Chevy Dealer, not that I'm an expert, or anything. With the limited information I've gathered, your problem, although not currently serious, could lead to that. The problen could be as easy as a loose gas cap, although chances are slim. The fix is not a computer reset on a '96, as was suggested by a previous poster(required for '04 and newer vehicles). The fix, rather, is a series of restarts (15-20), or a period of days(After you have securely tightened the gas cap). Ask yourself if you had just put gas in the car before the 'Check Engine' light came on. The gas cap in part of your "Emissions Control System."

The most likely remedy to your present problem, is a new O2 Sensor. It's a fairly common failure in vehicles of that age, and can be an indicator of more serious issues.

That being said, you can apply different potential solutions, and not solve the problem...spending good $$$ after bad. If you can't afford to replace the car, I suggest the proper repair before the whole situation goes south on you. It's kinda like the old FRAM commercial..."Pay me know, or PAY me later!"

Good luck!!!

[memyself]

oops

[memyself]

Some cheap people who have a bit of experience around cars drop the thermostat in water and heat it up... it opens up around 180 degrees. if it opens it's good.
------------ ------------ ------------ ------------
That is exactly what happened on the other car. It kept getting jammed, and causing all sorts of terrible problems, boiling over and whatnot, and all it took to fix it was an $11 part.[/quote]

Gd info but Id add "it has 2 temp ratings: ==Important it works right==
use a thin feeler gauge caught between the valve plate & body to suspend
the thermostat in a pot of water then heat.
The unit should start opening at a set temp & be fully open by a slightly
larger temp.
eg: Mitsubishi 2litre astron engine --- starts @ 90.6 deg C, fully open @ 104 deg C.

:wink: The other thing is, all the sensors are checkable with the aid of a good high impedance multimeter, its a gd way to start if you've not got a diagnostic unit.