Help? In, everything? MIL light is on!
#1
10-14-2013, 08:29 PM
Help? In, everything? MIL light is on!
Hey there everyone,
first off thank you so much for tolerating my ignorance!! I promise I'm not stupid- I'm really smart- I just don't know much about cars. I have a 1999 Audi A4 1.8T; I just got it last August, and I am in love with the way it hugs the road. I love the AWD, the sun roof makes me happy, and I call it my baby alll the time. It has 130K miles, but it runs so nicely!
But today... the MIL is on. Not blinking: it just stays on the whole time I drive. And what I don't understand is... my car is perfectly fine. the RPMs aren't extremely high, there's no hesitation, gas mileage is just as it always is (awesome), and I haven't heard any abnormal noises at all. I did some research and it seems like if nothing is obviously going wrong then I might not have that much to worry about... possibly a leaky valve, or something... nothing too bad.
But am I wrong about that? What various reasons can cause the check engine light to light up while my Audi is running perfectly? What's the most it can cost me (fyi: poor college student who couldn't deny herself a good deal and a great car)?
I'm definitely going to get it fixed. But I have about 500 miles left to go for the next oil change- and I would like to hold off on repairing whatever the problem is for when I get my oil changed. Think that's an okay idea?
Thank you so so much! I greatly appreciate it!!
first off thank you so much for tolerating my ignorance!! I promise I'm not stupid- I'm really smart- I just don't know much about cars. I have a 1999 Audi A4 1.8T; I just got it last August, and I am in love with the way it hugs the road. I love the AWD, the sun roof makes me happy, and I call it my baby alll the time. It has 130K miles, but it runs so nicely!
But today... the MIL is on. Not blinking: it just stays on the whole time I drive. And what I don't understand is... my car is perfectly fine. the RPMs aren't extremely high, there's no hesitation, gas mileage is just as it always is (awesome), and I haven't heard any abnormal noises at all. I did some research and it seems like if nothing is obviously going wrong then I might not have that much to worry about... possibly a leaky valve, or something... nothing too bad.
But am I wrong about that? What various reasons can cause the check engine light to light up while my Audi is running perfectly? What's the most it can cost me (fyi: poor college student who couldn't deny herself a good deal and a great car)?
I'm definitely going to get it fixed. But I have about 500 miles left to go for the next oil change- and I would like to hold off on repairing whatever the problem is for when I get my oil changed. Think that's an okay idea?
Thank you so so much! I greatly appreciate it!!
#2
10-14-2013, 08:47 PM
Welcome to the forums.
A check engine light (CEL, MIL) can light up for many reasons. The only way to know whether it is something to be concerned about or not is to find out what the code is.
Try taking the car to your local auto parts store and see if they will scan the computer for you for free.
The other option is to order a $10 VCDS cable from eBay and check the code yourself. You can download VCDS Lite for that purpose (you need a PC, not a mac, to do so.)
Once you find out why you're getting a code we can help guide you about whether it something that should be addressed quickly.
A check engine light (CEL, MIL) can light up for many reasons. The only way to know whether it is something to be concerned about or not is to find out what the code is.
Try taking the car to your local auto parts store and see if they will scan the computer for you for free.
The other option is to order a $10 VCDS cable from eBay and check the code yourself. You can download VCDS Lite for that purpose (you need a PC, not a mac, to do so.)
Once you find out why you're getting a code we can help guide you about whether it something that should be addressed quickly.
Last edited by BaseDrifter; 10-14-2013 at 08:49 PM.
#3
10-14-2013, 08:51 PM
^And Basedrifter posts just before I post with the same suggestions, dangit basedrifter, making me look like a scrub everytime :P
There's a number of things that could be causing the light while still driving normally, however we are not really going to be able to help you much as there are no obvious symptoms. Your best bet would be to take it to a autozone/advance auto parts/etc. and have them scan your car and tell you what the codes are then post them here and we'll help you out.
Alternatively if you are not near a store then you can buy an OBD-II to USB cord (often incorrectly advertised as vag-com) and just download VCDS-Lite (it's free) and scan it with your laptop. The cord is like ~$8
There's a number of things that could be causing the light while still driving normally, however we are not really going to be able to help you much as there are no obvious symptoms. Your best bet would be to take it to a autozone/advance auto parts/etc. and have them scan your car and tell you what the codes are then post them here and we'll help you out.
Alternatively if you are not near a store then you can buy an OBD-II to USB cord (often incorrectly advertised as vag-com) and just download VCDS-Lite (it's free) and scan it with your laptop. The cord is like ~$8
Last edited by Pbcrazy; 10-14-2013 at 08:53 PM.
#6
10-15-2013, 09:08 PM
Welcome to the forums.
A check engine light (CEL, MIL) can light up for many reasons. The only way to know whether it is something to be concerned about or not is to find out what the code is.
Try taking the car to your local auto parts store and see if they will scan the computer for you for free.
The other option is to order a $10 VCDS cable from eBay and check the code yourself. You can download VCDS Lite for that purpose (you need a PC, not a mac, to do so.)
Once you find out why you're getting a code we can help guide you about whether it something that should be addressed quickly.
A check engine light (CEL, MIL) can light up for many reasons. The only way to know whether it is something to be concerned about or not is to find out what the code is.
Try taking the car to your local auto parts store and see if they will scan the computer for you for free.
The other option is to order a $10 VCDS cable from eBay and check the code yourself. You can download VCDS Lite for that purpose (you need a PC, not a mac, to do so.)
Once you find out why you're getting a code we can help guide you about whether it something that should be addressed quickly.
So, my car isn't very loud AT ALL. I'm not smelling anything that bad, either. Tomorrow morning I might go look at my exhaust to see if there might be a hole in it or something...
But since there really doesn't feel or look or sound like anything is bad, do you guys think I could hold off for another 500 miles until I get paid a little more (haha) so I can kill two- or three birds with one stone? I just really don't want to dedicate my first paycheck I'm getting from my new job to disappear within a week, considering all the other monies I owe... But I'd rather my car be in good condition than give away some money that I don't have a particular due date to pay back, either!!
Thank you so much BaseDrifter, thank you so much Pbcrazy!! I really appreciate it!!
#7
10-15-2013, 10:05 PM
I'm kinda thrown off because as i did a bit of research...and code 4520/04520 does not exist. That being said with the description you gave of the code, it is likely the post cat 02 sensor has gone bad. The only purpose of the post 02 is to monitor the efficency of the cat and when it goes bad it just says that cat is bad. It is possible the cat is blown out/plugged up or you have other problems but if the car drives the exact same as it did before the light came on it is likely the 02.
As far as waiting: If it's the post-02 that is bad it's fine to wait, it doesn't do s**t for the engines running capacity. If it's the cat or another problem I wouldn't recommend waiting but you really don't know what's wrong until you just replace the 02 and see if the code sticks around, it's not expensive so I say just do it. But again, up to you and your budget
Edit: when you took it to the shop did they clear the code for you? And if they did did the light come back on?
As far as waiting: If it's the post-02 that is bad it's fine to wait, it doesn't do s**t for the engines running capacity. If it's the cat or another problem I wouldn't recommend waiting but you really don't know what's wrong until you just replace the 02 and see if the code sticks around, it's not expensive so I say just do it. But again, up to you and your budget
Edit: when you took it to the shop did they clear the code for you? And if they did did the light come back on?
Last edited by Pbcrazy; 10-15-2013 at 10:08 PM.
#8
10-16-2013, 02:48 AM
I'm kinda thrown off because as i did a bit of research...and code 4520/04520 does not exist. That being said with the description you gave of the code, it is likely the post cat 02 sensor has gone bad. The only purpose of the post 02 is to monitor the efficency of the cat and when it goes bad it just says that cat is bad. It is possible the cat is blown out/plugged up or you have other problems but if the car drives the exact same as it did before the light came on it is likely the 02.
As far as waiting: If it's the post-02 that is bad it's fine to wait, it doesn't do s**t for the engines running capacity. If it's the cat or another problem I wouldn't recommend waiting but you really don't know what's wrong until you just replace the 02 and see if the code sticks around, it's not expensive so I say just do it. But again, up to you and your budget
Edit: when you took it to the shop did they clear the code for you? And if they did did the light come back on?
As far as waiting: If it's the post-02 that is bad it's fine to wait, it doesn't do s**t for the engines running capacity. If it's the cat or another problem I wouldn't recommend waiting but you really don't know what's wrong until you just replace the 02 and see if the code sticks around, it's not expensive so I say just do it. But again, up to you and your budget
Edit: when you took it to the shop did they clear the code for you? And if they did did the light come back on?
To my knowledge, i think auto stores are not allowed to clear codes anymore, just read them.
Something about not being liable for any issues that may come, if a code is cleared and the customer didn't know about the problem and as a result, the engine blows up and they blame the auto store for clearing the code. Stupid reason but this is what they say....
#9
10-16-2013, 07:17 AM
The check engine light does not necessarily mean that your car has a serious problem. (All serious problems are reported more immediately by other lights or dash warnings.) It more likely means that there is an issue affecting its "efficiency" and/or emissions control. Generally speaking, especially since you got the free scan and it didn't report anything major, the car can be driven for a very long time with the light on, so it's nothing to worry about rushing.
Depending on what state you live in, the light can be a big problem when renewing registration. In California you need a smog check every two years, and you can't pass if the light is on for any reason whatsoever.
Depending on what state you live in, the light can be a big problem when renewing registration. In California you need a smog check every two years, and you can't pass if the light is on for any reason whatsoever.
#10
10-16-2013, 10:55 AM
The check engine light does not necessarily mean that your car has a serious problem. (All serious problems are reported more immediately by other lights or dash warnings.) It more likely means that there is an issue affecting its "efficiency" and/or emissions control. Generally speaking, especially since you got the free scan and it didn't report anything major, the car can be driven for a very long time with the light on, so it's nothing to worry about rushing.
Depending on what state you live in, the light can be a big problem when renewing registration. In California you need a smog check every two years, and you can't pass if the light is on for any reason whatsoever.
Depending on what state you live in, the light can be a big problem when renewing registration. In California you need a smog check every two years, and you can't pass if the light is on for any reason whatsoever.
I need to bring my 2001 Audi A4 B5 1.8T AWM in for emissions by next month! Its only about 20 dollars but still, its just another inconvenience for having a old car.
Its worth it for Audina, she's been doing better than most B5's that i read about on these forums for the couple years I've been a member.
