I have a 2003 Jetta 2.0l. Started the car the otherday and the car idled very rough, I noticed the check engine light was blinking and kept blinking for about 3 minutes and stayed on (oh by the way the check engine light has been on for about a month need to replace the O2 sensor) As I started to drive the car it was bucking and had no power, hills I drove up in 5th gear I had to down shift to 4th. Also I noticed I am getting interference on the radio, It radio noise doesn't speed up as the car goes faster just a constant sort of thumping static.

Check the normal stuff.
Idle control valve.
Plugs, distributer cap and rotor.
Check that your intake and air filter is clean.
You know O2 sensor could cause your car to run like this. Your problem will probably clear up after you replace that.
Fuel injection system was pretty good in those so probably not that.


I use to hate my Jetta becasue it seemed as if it was always broken. And towards the end it was but it was cheap and easy to fix. Parts weren't expensive. Anyway mine was 10 years older than yours so you may not even have standard distributer???

i had an extreme power loss on my 85'. there is a small test pipe on the exhaust system with a little rubber cap. the cap failed with a tiny bit of material still attached. so, when under accel it would open creating a MASSIVE leak. with the engine turned off it fell back into place. cool design feature, the pipe points directly at the wiring for the cold start valve (i think). hot gases distroyed the wiring. this same pipe design feature is on a 928. al blose had the same failure on his 928. mine was much easier to fix.

k

When you say you have to replace the oxygen sensor, is that because you pulled the codes and identified the problem? Or is it a guess? IME, the Oxygen sensor is rarely a problem, unless there's another problem that caused damage to it. There are literally HUNDREDS of codes, just for the engine. If the light is flashing, the owner's manual makes it VERY CLEAR that the car is NOT to be driven, as a condition exists which could cause damage to the engine. OBD 2 cars, especially the late ones, can be difficult to diagnose, that's why we access and use the codes to help us more quickly locate and repair the problem.

Advice from people with earlier cars, especially non-OBD 2, is a total waste of time and bandwidth ......the rules, indeed the whole ballgame, are different! For example, there is no distributor, no cap, no rotor, no emissions test port, and no idle control valve. There is, however, and air filter. If you've installed a K&N, it's likely to be a big part of the problem, along with the contaminated MAF sensor that it caused.

The check engine light is there because YOU NEED TO CHECK THE ENGINE! Novel concept, huh? Get me ALL the codes, including the COMPLETE text that follows the numbers, and maybe I can help you. The Cap'n

I need to say something about this.
Take your car to a local AutoZone, but only if you feel it is safe to drive your car, and they will always give the code number that comes up when they check the reason you are getting a code light that comes on.
They will not give the solution but only the code. Still not bad for free service.

We had this happen on my wifes 2001 Accord. The problem light came on and said check the engine. We thought the car had serious problems. We tried to get information from the dealer over the phone. They said, They could send a tow vehicle out which we would be charged for as well as in our opinion, an expensive fee to just tell us what the code implied and then more expense to solve whatever had made the light come on to begin with. We did and found the reason to be a fluke that the gas cap had not been clicked down tight enough.

Follow what the Cap'n suggests but also make certain you always fasten the fuel tank cap well or it will give the same engine light on problem with computer induced to correct running problems as it, the car computer, attempts to make some adjustments to overcome those false signals.

No matter what is done, the signal device will have to be reset before the signal warning will go off.

Just IMHO.

Cooltimes (Mike Cooley)

I often the on the 2.0 the cause most misfires are coil or plugwires there is a know problem with a faulty ground going to the coil....But more then likly it is the coil or a plug wire. A scanner will narrow it down to a individual cly.

If you plan on keeping this Vw Vag-com is your friend it is cheap and it much more of a detailed scan tool then the pieace of crap that the zone uses

I woulf think from your description it is a misfire

OK - So at least I said I wasn't sure that his Jetta had a distributor....
I did have to replace my O2 sensor on my Jetta.
He lives in NJ. I'm from upstate NY.
The snow kills O2 sensors. It rusts them out. It's possible with the way his car is running. Definitely airflow or electrical. I wouldn't say advice from anyone is a waste of "time or bandwidth". We're all in the same boat. We're not there listening to the engine, experiencing the symptoms. The radio feedback doesn't really fit.

radio interference makes it seem like there is something wrong with the ignition system. Pulg wires, coil . . . something, I don't know of anything else that causes radio interference.

I got the code for the O2 sensor from a VW Repair shop in NY, the sensor cost $180, so I was hoping to get it soon (the car was running great by the way). I agree because of the radio interference it sounds electrical, I spoke to a buddy, he said it sounds like the coil, they have a tendency to get small crack, that one goes for $213 nothing is cheap.

You should check out GAP, they carry all the OEM stuff for your jetta at decent prices. Germanautoparts.com

Do the old spray bottle trick get you a bottle fill with water and spray dow the coil and the plug wires the coil on this car is under the seconday air pump so it is a pain to see. But you will probaly start to hear it arching

Im waiting till it gets dark and check for arcing

By the way, on a OBD2 VW, if the CEL is flashing, you need to stop driving it ASAP. Solid Cel: look into a problem. Flashing CEL - something is seriously wrong.

On my 98 Golf, arcing from the coil when wet would not even throw a CEL. The car would just die.

Zach

I had a VW Corrado with the same problem minus the radio interferance. I replaced the ignition coil, problem solved. Good luck.

Just a note of advice. These guys have pretty good prices on VW factory parts:

http://www.partsplaceinc.com/

Even if you don't buy from them now, their catalog makes for good reading. FYI - They sell a scan tool (#SN20316) for $69.95 that connects to the USB on a laptop. Download the consumer VAG-COM software from Ross-tech.com. That and a Bentley manual allowed me to diagnose a check engine light that was literally a $2 fuse in my '99 Golf.

Lots of good information has been posted allready. But I have a few points I would like to add.

#1 a flashing check engine light means that there is an engine miss that could be "catalyst damaging" this is the only reason the check engine light will flash. Dont drive it unless you want to ruin your cat.

#2 Common misdiagnosis. Some codes (ie 171 & 174) are defined as Lean O2. This means that the 02 is reading lean and could be a bad O2 but is more likely to be a missing engine. During a miss the oxygen in the cylinder is unburned so the O2 sees it and triggers that code. The computer assumes the mixture is lean with the logic that if it see's oxygen that there must not have been enough fuel to burn all the oxygen. But someone will say... if its missing it should trigger a misfire code. NOT ALWAYS! My point is you may not have needed a O2 sensor at all.

#3 The problem with driving around with the check engine light on is that when a "real" problem develops you dont immedialy run out and get the codes. You probably do have misfire codes like 300 random misfire or 301 cyl #1 misfire ect. When your check engine light came on you ran and got the codes checked even though it was running fine. But when the engine starts acting up ect you didn't run out and get the codes checked because the light was allready on.

Point of #3 is get that light out. A engine with a proper working O2 will run better and use less gas and the gas savings would have probably paid for the sensor by now.

example of why #3 is important. My wifes caravan had an EGR code turning the light on. She (Me) ignored it cuz thats just for emmissions. Then when it triggered a Cooling Fan relay trouble code there was nothing to tell us the code was in there because the light was allready on so we didn't know it. All that we knew is that the AC quit working. A normal function of the computer on her car is when there is a Cooling Fan relay trouble code the computer disables the AC to prevent overheating. Well a week later (she mostly drives hiway) her van overheated in bumper to bumper traffic and it was a big hassle. After finding the fan not working and diagnosing it based on the trouble code I found in the computer I realized she had been suffering through with no AC for a week for no reason. We could have known about the problem a week before, fixed it and avoided the breakdown and the tow. (no to mention the risk of overheating and damaging the engine). What if we would have had some shop try to fix the AC? How many misdiagnosis's and parts changes would we have had to endure before they realized it was the fan relay?

Point being. Get those lights off folks.