PDA

View Full Version : 750 Rpm's Help



cab7a4
11-13-2008, 01:42 PM
Once my car warms up it idles at 750 rpms ...seems low cause when i turn the wheel it make that power loss sound!! can anyone else verify what their car normally idles at?

i have a 2005.5 b7 a4 2.0t

Latin Audi
11-13-2008, 01:47 PM
have you scanned for any codes? i have on 05.5 and this happens to me along with fuel cuts and it is currently at the dealership. From the research I did I narrowed it down to a bad fuel pressure sensor (throtle sensor) which there was a recall for on June 1 of this year. My VIN didnt fall under this recall. I also found out that it could be excessive wear on the cam lobe (there is a TSB for this) or a bad fuel pump.

Again this is what I found out for my problem (low idle + fuel cuts) but this might help put you in the right direction. Best of luck[up]

cab7a4
11-13-2008, 01:50 PM
have you scanned for any codes? i have on 05.5 and this happens to me along with fuel cuts and it is currently at the dealership. From the research I did I narrowed it down to a bad fuel pressure sensor (throtle sensor) which there was a recall for on June 1 of this year. My VIN didnt fall under this recall. I also found out that it could be excessive wear on the cam lobe (there is a TSB for this) or a bad fuel pump.

Again this is what I found out for my problem (low idle + fuel cuts) but this might help put you in the right direction. Best of luck[up]

thanks alot my friend i will have to investigate....cause the audi dealership near me was no help!!!!!

Latin Audi
11-13-2008, 02:24 PM
The dealership just called and said I need a new "Fuel sending unit". Never heard of this but from what Ive briefly looked up it just tells your fuel gauge how much fuel you have left. Could this really be causing hard starts?

cab7a4
11-13-2008, 02:28 PM
wow...it sounds like it could be more than that...u might want to harass them a little more

Slo.Mo.Shun.
11-13-2008, 03:07 PM
My car was doing that before the fuel pump went. That car would even stall once in a while.

QTC
11-13-2008, 03:21 PM
My car (although its a 1.8T) idles about that too. I'm trying to diagnose why, so I haven't done this, but you can change the idle value with VAG-COM. But I do think that a falling idle is a sign of fuel pump failure, espicially if you're getting a fuel cut too....

cab7a4
11-13-2008, 04:20 PM
hey gentleman, i really apprieciate your input and all the positive feedback!!!! thanks so much



corey

Latin Audi
11-13-2008, 05:03 PM
yea, im going to talk to them in the morning. I dont believe this part could possibly be causing my problems. Im going to see if they even checked for cam wear or fuel pump. Thanks for the input and ill post back tomorrow when I know more

Alkemix
11-13-2008, 06:19 PM
RPM's drop when you turn the wheel in idle. You will notice, if you have a boost gauge that your boost will go up and down too slightly. It's not uncommon in ALL cars. You get that power loss sound, I know what you're talking about. I don't think it's a big deal. Just keep your car at a slow roll when turning your wheel instead of dead stop, unless you are parallel parking. Problem solved? Your car idling at 750 does seem low, but mine idles just under 1k too. I've noticed most 4 cylinder cars do that.

Nico
11-13-2008, 06:27 PM
RPM's drop when you turn the wheel in idle. You will notice, if you have a boost gauge that your boost will go up and down too slightly. It's not uncommon in ALL cars. You get that power loss sound, I know what you're talking about. I don't think it's a big deal. Just keep your car at a slow roll when turning your wheel instead of dead stop, unless you are parallel parking. Problem solved? Your car idling at 750 does seem low, but mine idles just under 1k too. I've noticed most 4 cylinder cars do that.

The reason you RPM drop when you turn the wheel at Idle is due to the power steering pump adding load to the engine hence the revs drop.

cab7a4
11-13-2008, 09:51 PM
The reason you RPM drop when you turn the wheel at Idle is due to the power steering pump adding load to the engine hence the revs drop.

i got that point...but it shouldn't drop to the point of your car almost stalling!!! that's the concern i had.

Latin Audi
11-17-2008, 10:47 AM
Alright, so after all my hard start problems and all the research I did to figure out what the problem was it turns out I was right[:D]. I took my car into the dealership last Thrusday I explained to them of my nagging hard starts which would only happen after I've been driving around and I go run some errands and after turning the car on/off 2-3 times it would die w/o even putting it into gear. I told them about the recall on the thrust sensor and of the TSB of excessive cam lobe wear and also asked if they could check the fuel pump.

I get a call on Friday saying they found the problem and that it was a bad "Fuel Sending Unit". I'd never heard of this so I did my hw and found out its only purpose was to read how much fuel I have left. So obviously I wasnt buying their diagnosis and I called some euro shops and other dealers and they told me it could not possibly be causing my hard starts. I then call the dealer and explain to them that I dont think this Fuel Sending Unit could cause my hard starts and they give me the "...well I have to trust my techs diagnosis" bs. Funny enough they phone me Sat afternoon to say my car is ready and that the dumb teen at the service desk had made a mistake and that it was ACTUALLY a bad low pressure thrust sensor and bad fuel pump control module. Now this sounds more like the cause but how the hell did they tell me the wrong part??[evilmad] Anyways my car runs fine now so I could not be happier.

Ive posted below the diagnosis sheet along with an exlpoded assembly of the parts they replaced[wrench] oh and I DO NOT have a Cabriolet, they fd up.

Diagnosis:
http://www.audizine.com/forum/picture.php?albumid=497&pictureid=1705
Thrust Sensor:
http://www.audizine.com/forum/picture.php?albumid=497&pictureid=1708
Fuel Pump:
http://www.audizine.com/forum/picture.php?albumid=497&pictureid=1707

cab7a4
11-17-2008, 12:25 PM
Alright, so after all my hard start problems and all the research I did to figure out what the problem was it turns out I was right[:D]. I took my car into the dealership last Thrusday I explained to them of my nagging hard starts which would only happen after I've been driving around and I go run some errands and after turning the car on/off 2-3 times it would die w/o even putting it into gear. I told them about the recall on the thrust sensor and of the TSB of excessive cam lobe wear and also asked if they could check the fuel pump.

I get a call on Friday saying they found the problem and that it was a bad "Fuel Sending Unit". I'd never heard of this so I did my hw and found out its only purpose was to read how much fuel I have left. So obviously I wasnt buying their diagnosis and I called some euro shops and other dealers and they told me it could not possibly be causing my hard starts. I then call the dealer and explain to them that I dont think this Fuel Sending Unit could cause my hard starts and they give me the "...well I have to trust my techs diagnosis" bs. Funny enough they phone me Sat afternoon to say my car is ready and that the dumb teen at the service desk had made a mistake and that it was ACTUALLY a bad low pressure thrust sensor and bad fuel pump control module. Now this sounds more like the cause but how the hell did they tell me the wrong part??[evilmad] Anyways my car runs fine now so I could not be happier.

Ive posted below the diagnosis sheet along with an exlpoded assembly of the parts they replaced[wrench] oh and I DO NOT have a Cabriolet, they fd up.

Diagnosis:
http://www.audizine.com/forum/picture.php?albumid=497&pictureid=1705
Thrust Sensor:
http://www.audizine.com/forum/picture.php?albumid=497&pictureid=1708
Fuel Pump:
http://www.audizine.com/forum/picture.php?albumid=497&pictureid=1707

Dude, you are awesome. thanks so much!! i will have to remember that .....forget that im gonna print this :) so that if this starts happening i will know what to do.....thanks so much again

Alkemix
11-18-2008, 12:54 PM
i got that point...but it shouldn't drop to the point of your car almost stalling!!! that's the concern i had.

Stalling is in a whole new ballpark than a drop in RPM. Get it checked out. still does the problem persist if you're on a slow roll while turning? When you stall, are you intentionally stress testing your car at a dead stop, moving the wheel left and right to see if you can stall it? Or is it that you're doing a normal parking/dead stop maneuver? Actually, when you mentioned power loss sound i imagined you were talking about the stutter of the power steering or the wheel or tires, whatever it is, that you get in a car if you turn your wheel say fully to one direction during a dead stop. Anyways, sounds like you might have something else on your hands.