I have an audi a4 3.0 2003....my car died as I was driving on the highway... It won't run over... Not sure if it's the fuel pump or a sensor how do I make sure?


Asked by Jun 17, 2014 at 12:18 PM about the 2003 Audi A4 3.0 quattro Sedan AWD

Question type: Maintenance & Repair

65 Answers


The first thing you should do is scan the computer with a computer reader and tell us what the codes are. if you can't however do that then it sounds to me like a fuel issue try having the fuel filter changed to start. This is a cheap and quick thing to change. Often this gets clogged over a year or 2 of using bad or not high enough octane gas. then have it checked for spark. Next check the air flow sensor and check your filter. the air flow sensor can be cleaned with air flow cleaner be careful and don't do this while it is still attached to the car unless you want to ruin your engine. Remove the entire sensor housing and just spray into it one side then the other till it looks clean. this should be cleaned once a year. and depending on your filter at least replaced every 1 -2 years depending on how dirty it is. Try this and then if it still does not work check your fuel pump open the back set turn the key and listen for the humming noise it makes. if it is not present you need a new pump or the wiring has gone faulty. Hope this helps

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I went to go get the car towed a couple hour later and it started... Computer reads 0320

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Symptoms. Check Engine Light will illuminate. In many cases, no abnormal symptoms may be noticed. Hard starting/cranking without starting. Engine hesitation or stalling. Engine dies and will not re-start. Common Problems That Trigger the P0320 Code. Defective Crankshaft Position Sensor. Faulty or corroded Crankshaft Position Sensor wiring or connections. Defective Camshaft Position Sensor. Rough running/misfiring Engine. in short replace the camshaft position sensor and it should fix your problem make sure to check the wiring to the sensor as well

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I have the same problem with my 99 audi a4 however he check engine light is not on, I've replaced both the fuel filter and the crankshaft position sensor and it still won't start. I turn the key and hear the fuel pump engage. It turns over just fine and even after trying many times so I don't think it's the battery . Does anyone know what else this could be? Or At this point should I just bring it to get diagnosed?

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check for spark. if you have no spark it won't fire. Pull out all your plugs set them within visual of your drivers seat pluged in next to a metal object in a dark place and turn the key. or simply have some one else turn the key for you. If you have no spark you need a new coil pack. If you have spark check the cylinders for gas. Its most likely fouled plugs or bad coil


Ok so I changed the plugs and checked all the coil packs they have spark, still no start. Someone told me to try to start it with the mass airflow sensor unplugged to see if that was the problem. Still didn't start. After changimg plugs and having it hooked up to a running car it sounds like it really wants to start with more engine shake and sputtering. Any idea on where to look next?


you did check your cylinders for fuel correct? Also try having the battery tested. if its chugging with a boost it may not have a good strong charge amps. Have your battery tested for amps and voltage. Start checking your vacum lines for breaks also unplugging the mass airflow sensor wont really do that much and could screw up your cars system. it would be a good idea to clean that maf sensor


I will do research on how to check for fuel in cylinders and also where the vacuum lines are but do you think it could be a fuel pump relay under the steering wheel? Even a slight crack in vacuum line would affect the start? Thanks for all your help


Haha unless that's where the spark plugs are in that case when I took them out for spark plugs had oil on the contacts I cleaned out the threads as best I could and replaced the plugs with new ones. After that it sounded much more inclined to start but still did not start.


Or fuel with carbon, not oil


oil on the plugs would cause the car to not start. And if you have oil in the spark plug holes that is a bad thing as it ussaly points out a leaking headcover gasket. As for checking for gas when you got the plugs out and have cranked it to check for spark u can use a plastic stick and just swab the cylinder threw the spark plug hole. if it comes out dry there is no gas if it comes out wet and smells like gasoline you is good. if it comes out wet and smells like piss its anti freeze. if its oily you got oil in the cylinders. Its probley not any of the last two but it gives you an idea what could end up in there if something was broken. and yes if you had not noticed before the stuff vw and audi use for rad fluid smells like piss.

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and yes broken vacum lines can in turn cause your audi not to start as most of the system it runs is vacum based.


Its not an answer but a problem also, I think my problem is also same to the one above, because my car won't fire the engine and it also died while I was driving and won't start again, its a 1.8T 2000 model, I changed my battery 5 days ago, do u think its the fuel filter or wiring that went bad?


hard to say but best guess its one of 3 things fuel pump, fuel filter, or fuel regulator. Have a garage change the filter since its a messy job with gasoline. its your first cheapest option. Also check the spark and air flow while your looking and make sure your coil and plugs are good and change the air filter if it loks dirty and clean your maf.


Did all of that bt still won't start, checked the fuse box and all of them are still in working condition

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ok well then your going to have to start from the top. So we know fuel is not the issue so check it off the list. so give me more of a full picture as to what the car does. Does the car sputter and try to start or does it just sound like its turning and nothing is happening ? do you have a little key icon on your dash during the power on position of the key. start by checking for spark and checking that all the air ways and crank case hoses are not cloged.


Yes it does sputter and try to start, turning the key on, it does show the key icon for a few seconds and it disappers but the EPC light stays on

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ok well try this take the car to a garage with ross tech software and have the car scanned or go to amazon.com your self and find a dongel for your car for like 14 - 34 $ and then scan the car for the codes your getting from the ecm. This will greatly speed up the repair process and keep us from shooting in the dark. And you answered my security question. If it was an igntion or security issue it would start then stall a second later.

I have a 2003 audi a6 3.0, changed all the spark plugs and coil packs, both valve cover gaskets ect. It still sometimes has a rough idle with a epc light on. Shut it off and turn it back on its gone. Also 123 cylinders are misfiring I don't know what could cause this. Also I'd like to add I disconnected the negative termal to the battery to reset the valves and now my car won't start I have no idea what's wrong with her..

Codes are p0300 P0301 P0302 P0303 P0130


po130 is the oxygen sensor the rest is all miss fire codes. Best guess is it is either a fuel issue or a a relay. or just simply the oxygen sensor. Have the fuel system pressure tested after the regulator on both rails i figure this may be where your issue is. I also been reading some other boards and they were mentioning the ICM (ignition control modules) would seem the cars have 2 of these which might explain the reason one side is failing.

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Okay thank you I'll deff be getting back to you on this one

Do you think it could be my crank shafts sensor due to misfiring? And I do get the smell of gas inside my car


its very possible this could be the trouble part as well its a fair bit of work to put this part in and it has to be done right. that part is like a timing gun it lines up to a hole spun by the cam. has any one ever chanaged parts on the head? this part does not often go bad.

Nope only changed the valve cover gaskets. I only disconnected my batter terminal for 5 min to set everaging back to stock and now it won't start?

Didn't clean or touch anything other than that and it was just the negative termal


Ok i looked into this a bit further and what i have found is that if the crank case hose system has an issue like say a leak it causes this problem. The most complete kits i have found so far are on www.autopartsway.com I would start looking at all your plastic ventalation hoses and find the one thats leaking. fyi i would guess the one heading to the misfiring head is the issue case :P

Okay I'll get back to later on today to see if I can find it.

And this will cause my car not to start? I know I heard posing noises when it did run and shut it off so that's a good possibility


yep if half the engine don';t run right it can cause it to not start. But that could also have been from you disconnecting the battery. Sometimes its good other times it wipes out the entire learned system. You may even have to have the throtle body readapted. If you got rosstech software and usb harness thats not ussaly a problem. Find your leak plug it up and replace the hoses see if it works and let me know.

Okay thank you so much

Just gonna buy the whole vacume set up


that is ussaly a good idea to do so. It may be a little pricy but its worth it.

Also got the fuel pump and fuel filter so hope all goes well


You probably wont need to replace the fuel pump that part seems to be doing its job. Try just replacing the air hoses first and then replace the filter and pump only if it still does not run right. You may replace the fuel filter if its not been done in a long period of time but as long as you keep using the best gas possible it shouldn't get dirty and will be fine.Since the car smells like gas that means fuel flow is not the issue to the rails.

So I took apart the crank ventilation hoses they where all slugded up with oil and pretty much broke apart in my hands. I'm missin one pice to it which is the in that comes up from the engine itself getting it Tuesday I'll let you know how it goes when together

All of the pieces where so brittle and just broke in multiple places


yea it happens with all these modals not alot of people realize just how bad those pipes get till some one says hey look at these !. :P It should run proper when your done.

Hi I have an Audi a4 2003 and it won't drive forward when put into gear. My epc light is on and the code is for a speed sensor , would that cause my car to not shift in to drive it goes in reverse with out a problem?


it might if its the one attached to the transmission. But this could be another more serious issue. Try replacing the trany speed sensor and see if it fixes the issue. Also if you can if you don't have one Get some one to scan the car with rosstech software and usb dongel.

Is it possible that it could be a epc transmission solenoid ?


i would start looking at the first things first but at this point any part of your car could be the issue. best we can do is narrow it down. Best thing you can do right now is scan your car.

I have the 2003 3.0 car still wouldn't start and I noticed that in my fuze box are the fuel pump and ecu fuzes don't light up at all. So fuze reley maybe? You think I blew them out wen I disconnected the negative battery and plugged it back on?



what do you mean by the fuses don't light up? did you use a tester in the slots? they are not light bulbs if that's what your thinking. Pull it and check the inside of it. but if your not very car savy look for a vw /audi specialist shop and have them look at it would be your best bet to get it fixed fast and easy


QUESTION: i have an audi a4 1.8 .. The engine turned off while running in the highway now we replaced the timing belt thinking that would be the problem but now the engine wont turn on .. It sounds like the engine is rotating but no sign of cranking ? Please help

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best way to find out if everything is moving is take your oil cap off and when some one cranks the engine look for a sign the sames are turning. This sounds like it may be a fuel or a spark issue tho. try having the codes read and see what comes up. and vw/audi specialist should be able to do it.

I have Audi A4 3.0 engin earlier last week its started to loose a lot of power and started to jerk around 2nd and 3rd gear what could be the problem


A loss in power can be a number of problems. Your most likely suspect is either a a bad maf sensor. clogged breather pipes, poor spark or bad sparkplugs, lack of fuel flow. Its all about narrowing it down. I ussaly start with all airways and work my way to spark then gas. Try removing all the air duct and checking all the sensors between the throttle body and air box, also check your filter. This would be a good time to clean the maf sensor while its out. Also check your throttle body and see how dirty it is, Do not remove it, You can but then you need to readdapt it and you probably don't have the software to do that. Once done hear go threw all your vacum lines and any plastic pvc. Quite a number of these 3.0's have problems with the pvc falling apart and causing stalling or lack of power issues.

Also can be the engine wired harness need to be change

Can the crank ventilation hoses throw a code for a check engine light to be on? I traded the audi for a 2000 vw Passat 2.8 5 speed and the crank ventilation hoses are not the right ones

But there is no misfire so idk


yes they can threw a code. There is particular vacum boxes that the system needs and with out the proper hoses it will cause idle and drive issues. have it scanned and see what the codes are.

Occasional EPC light and no start. Sometimes runs good and sometimes rough. Replaced fuel filter. Ordered CPS today. Not starting now. A4 2004 3.0.


replace your crank case hoses and it will start... the 3.0L engine had a high dependency on crank case hoses for running and idle speeds. You will likely find the crank case hose has snapped some where and will likely disintegrate when you go to pull it off. order the whole pvc kit it is worth it. temporarily find the leak and wrap the hose with electrical tape till you get replacements.

Ok I have a audi a6 2.8 Quattro I have a problem with it when I start the car it says it is almost over heating and when it is running it runs roughf it bogges out but then go back and idols ok but keeps doing it for while then stops but when u go to drive it it will only go 20 mph then it starts jerking and dose not go faster like it don't shift or something but the rpm will keep going up if hitting the gas bit keeps like jerking and bogging out I thought it mite be the cat casue it smells like ita going out and bad and it sputters at tail pipe so could that be y it say its over heating and won't go faster than 20mph but when I touch the radiator it is not hot and it only rum for few mi s then say its over heating what do u guys think could be problem


if the car says its over heating it most likely is. When was the last time you had the timing belt done? as this ussaly indicates when the last time the water pump and thermostat was done. If its been over 90,000km then you had best get it done asap this job ussaly includes you to get done the pulleys, tensioner, water pump, thermostat, and hardware. It should correct the problem provided the temp sensor is alright. If the car reads that it is overheating it will often put the car into safemode which reduces rpms and movement.

I have an Audi A4 2003 and it stopped working after u noticed there was oil in the spark plugs i replaced the spark plugs the and stopped the oil leak. I also replaced the crankshaft sensor but it won't start. It sounds like it's gonna turn on but it won't. What else could be going on ?


check all the air ways and pvc you likely have clogged crank case hoses

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I've got a 03 audi a4 quattro 3.0 has 126k and my CEL came on with 3 codes OBD2 p0421 p0431 p0392. The car runs and drives great sometimes when I'm at idle at a traffic light, stop sign or for about 15 minutes of idle in my driveway my RPM gauge will spike up to 2,000 and come back down and putter little bit but then run and Idle fine. I just bought and replaced the spark plugs and all 6 coils. I had ordered a camshaft position sensor the one for the driver side at the rear of valve cover. So hopefully that takes care of the code for that. Now for the p0421 & 431 code. I checked the catalytic converters with an infrared temperature gun and the temperature for the inlet was about 60 degrees hotter than the outlet do you do you think the O2 sensor is bad or I need a new converter if the sensor is bad should I change both or should I just change one sensor?


there is likely not a thing wrong with the cat's to start off do you buy high octane gas from the cheapest places you can find ? if yes then you likely have been puting low grade gas in your car and its starting to take its toll. Try going to the gas station that sells the best quality gas with 91-94 octane gas such as petro canada or sunco if your in the states. get a couple bottles of 44-k and wait till your almost empty on fuel to change to the new fuel do this for 2 tanks of gas and see if it helps. also try and get ethanol free gas. these cars don't seem to like it. shell usually does not have ethanol in their gas. hope this helps let me know if it doesn't i imagine it will tho.

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so my car died on me a while back couldnt start it tried reconnecting the battery didnt work i noticed that after reconnecting the battery my dash said press clutch to start the catch is that my car is a automatic... so i towed it to a friends came back to work on it the next morning and it started i drove it home did fine but when the ca got warm it kept throwing false codes such as the car is low on oil and coolent beeps everytime i touch the gas. but the car will die after a while of driving and will not start for hours... i do not know what the problem is codes said cats but catts are brand new...... only half of my dash works now rpms dont speed does lights dont gas does and my heater lights dont work nor does my cig lighter on center console if anyone has any answers please help......


check your fuse box and your ecu you likely have corrosion in one or the other or both. My guess is the ecu is failing tho. its liekly gotten full of water.

2003 A4 3.0 cranks but won't start it was running parked it for a few hours and then it wouldn't start. I heard the fuel pumps goes out on Audi alot so I disconnected the fuel line on the motor turn the key no gas came out . And no humming from the pump. But i also had the crankshaft sensor code come up. If it's bad would it not give power to fuel pump to pump or it wouldn't matter ?


if you hear no hum at the pump first check the relay. listen for the click or pull a diffterent relay thats the same one and swap them and see if it turns on. other wise check the wires if nothing else its the pump.

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