editas

Sorry if this is not the proper area to post this thread.

I`ve got 2 problems with my audi (2004 Audi A4 1.8T, 83,000 miles)

1.Sometimes when I turn on my car while it is still in park the RMP`s will go up, usually to stop this I press the gas pedal and rev the car up until it drops under 1000 rmps, if i attempt to put it in drive while the rpm's are flucuating it will turn off

2.when I got to turn on my car sometimes it wont turn over, you can hear the engine trying to turn over (its almost as if the car has no gas in it) usually i sit there struggling with this and end up having the car turn on by pumping the gas pedal, almost like the gas is being blocked and by pumping the pedal its clearing the pipes or air or something but it usually takes me about 5 try's to turn it on

Could this be sludge build up, o2 sensor, throttle body cleaning? it doesnt happen often maybe once a week ( so far I've only changed Ignition coils/spark plugs but I dont think these are relevant to this problem)

Any answers or same experiences are greatly appreciated

dsq

1) how high is the tach going up to when you first start the car? going up a bit then back down to around 1000rpm is normal

2) not sure. check fuel pump, or battery...

perry1211

my car is having the same problem but mine is 5 speed. and if i leave it running it goes back to normal and starts running find.

does anyone know what this problem can be?

1BODAUDI

yea its your air control valve... there is a lil screen in there that the coolant goes through and when its blocked up it makes the car idel funny..the rpms go up n down until it warms up then it will stop..... if that aint the case to my knowlage it higly possible its bad fuel but im 97% sure its your air control valve

i had ur 2nd problem as well but wit me it was when i turnd the car off to put gas and after putting the gas trying to start it it wouldnt start i would have to pump the gas and jus hold it over untill it started later to find out it was the fuel pump...its never good to allow your car to go into the red cause there can be moistur and other sh*it jus sitting at the bottom of the tank and your fuel pupmp will sometimes pick it up and cause it to fail thats why pumping it so many times help

perry1211

ive contacted the dealer they dont know what the air control valve is. is there another name for it??

and does this effect my driving at all?


does the part need to be replaced? or need to be cleaned??

please let me know.

thanks,
alot

wirebeans

Change the fuel filter, are you the original owner? IF not the fuel filter probably never got replaced. what's the milage on the car?

perry1211

hi,

im not the origianl ower but i got the car at 50,000 km from the audi dearship and the car has 81,000 km now.

what do you think it could be> fuel filter?

wirebeans

The only time engine idle rough like that is either a bad PCV valve, or clogged fuel line or bad spark plug or ignition coil.

Since your car never got the fuel filter changed, I am just going down the list with the cheapest required service. It's only $30 bucks and it's a easy swap, location should be under either right hand or left hand side rear door. Just don't smoke while you do this one.

If that doesnt solve the problem, then change PCV valve next, bad PCV makes engine stall out of no where. you should really change it anyways with those milage on the car.

perry1211

hi,

when the engine idels, meaning the rmp is going up and down while im stopped does that mean the same problem? and i should change the fuel filter and PCV valve?

wirebeans

The engine will idle at higher RPM is when engine is cold for a minute or two, but after that, it should be stable at around 600~750 and not jump up and down more than 50~100 RPM.

If you notice rpm drop lower and than back up when you turn on your a/c or head light, or blinker, or step on the brake (your case). that normally means a weak battery. But the drop should be very slightly.

If your car still have the original battery, it's time to get a new one.