A6 2.7t Boosting Issue
Thread Starter
|
1st Gear
Joined: Mar 2009
Posts: 30
A6 2.7t Boosting Issue
2001
Audi a6 2.7t
Manual 6 Speed
120,000 Mi
Ok before anything I'm going to start out by listing all of the things that have been done that have not fixed the problem. Kind of long sorry...
Oil Change $100
Spark Plug change $100
Fuel Filter Change $30
Air Filter Change $20
Clutch fluid $100
Transmission Fluid change $100
New Fuel Pressure Regulator $120
FPR Vacuum line
New Diverter Valves $100
Boost leak test / corrected all leaks and new boost hose kit $150
Timing Belt/ Water pump / Thermostat Change $1,175
New Fuel Pump $195
Tested at Import shop with VAG COM and no codes thrown $100
Fuel Injector Cleaner $10
Fuel System Service done $171
MAF sensor cleaning/ even tried out cousins 2.7t MAF sensor $10
When I first purchased the car it had all the feel of a turbo charged engine, head slapping into head rest and everything. All of the sudden one day it lost all the power it once had. Feels very sluggish from a stop. And I mean sluggish like little beat up Honda cars going faster then I can from a stop light. Right when i switch gears the car will jerk a little. Engine sounds like a friggin Diesel engine when running like this. I can sometimes get boost again if i hit 3000RPM in 3rd, release gas pedal then punch it again. Sometimes it will come back at the most random times and sometimes not. Also when the car is running rough the stick shifter is a little hard to put into gears (has even grinded on me before) and when the boost returns shifting is really smooth, shifting gear and all around no jerk after gear change or anything and again slapping head back into headrest at lower gears.
Alot of the times the boost returns after I go to a gym that is located at a higher elevation then where I live, however it only returns on days after I let it sit while in the gym then come out and it is drying outside from an afternoon of rain. One day I tried Fuel Injector cleaner on an empty tank then filled ofcourse, It cleared the problem for one whole day I dont know if it was just a coincidence or what. There is also one thing the car does somtimes mostly when not fully warmed. (I try not to run it like this I Promise) When coming to a Stop sign in a hurry I'll do a California stop and take off in 2nd the brakes suddenly become applied and ESP light begins to flash. Kind of dangerous at times also. I have recently taken it to a new shop, and explained the ESP story to a technician. He is almost positive it is the sensors for the ESP that are faulty and it is causing incorrect readings with the ECU and the quattro system causing my problems. He said the charge is $97.00 for diagnosis to look at things. Do you guys think it is worth it to do it or will it just be another waste? There is a couple of things I suspect and I wanted to know if i might be on the right track. 1 is the N75 valve I heard these cause a lot of boost problems when they go bad. 2 is the N80 Vaper purge valve or the lines to it because I recently had a flat front right tire and I herd sometimes this damages the lines. 3 Oxygen Sensors - Will this always throw a code when bad or a CEL? Any Help would be greatly appreciated. I love this car more then anything its my pride and joy and I'm running out of options and money I really don't want to sell it.
Audi a6 2.7t
Manual 6 Speed
120,000 Mi
Ok before anything I'm going to start out by listing all of the things that have been done that have not fixed the problem. Kind of long sorry...
Oil Change $100
Spark Plug change $100
Fuel Filter Change $30
Air Filter Change $20
Clutch fluid $100
Transmission Fluid change $100
New Fuel Pressure Regulator $120
FPR Vacuum line
New Diverter Valves $100
Boost leak test / corrected all leaks and new boost hose kit $150
Timing Belt/ Water pump / Thermostat Change $1,175
New Fuel Pump $195
Tested at Import shop with VAG COM and no codes thrown $100
Fuel Injector Cleaner $10
Fuel System Service done $171
MAF sensor cleaning/ even tried out cousins 2.7t MAF sensor $10
When I first purchased the car it had all the feel of a turbo charged engine, head slapping into head rest and everything. All of the sudden one day it lost all the power it once had. Feels very sluggish from a stop. And I mean sluggish like little beat up Honda cars going faster then I can from a stop light. Right when i switch gears the car will jerk a little. Engine sounds like a friggin Diesel engine when running like this. I can sometimes get boost again if i hit 3000RPM in 3rd, release gas pedal then punch it again. Sometimes it will come back at the most random times and sometimes not. Also when the car is running rough the stick shifter is a little hard to put into gears (has even grinded on me before) and when the boost returns shifting is really smooth, shifting gear and all around no jerk after gear change or anything and again slapping head back into headrest at lower gears.
Alot of the times the boost returns after I go to a gym that is located at a higher elevation then where I live, however it only returns on days after I let it sit while in the gym then come out and it is drying outside from an afternoon of rain. One day I tried Fuel Injector cleaner on an empty tank then filled ofcourse, It cleared the problem for one whole day I dont know if it was just a coincidence or what. There is also one thing the car does somtimes mostly when not fully warmed. (I try not to run it like this I Promise) When coming to a Stop sign in a hurry I'll do a California stop and take off in 2nd the brakes suddenly become applied and ESP light begins to flash. Kind of dangerous at times also. I have recently taken it to a new shop, and explained the ESP story to a technician. He is almost positive it is the sensors for the ESP that are faulty and it is causing incorrect readings with the ECU and the quattro system causing my problems. He said the charge is $97.00 for diagnosis to look at things. Do you guys think it is worth it to do it or will it just be another waste? There is a couple of things I suspect and I wanted to know if i might be on the right track. 1 is the N75 valve I heard these cause a lot of boost problems when they go bad. 2 is the N80 Vaper purge valve or the lines to it because I recently had a flat front right tire and I herd sometimes this damages the lines. 3 Oxygen Sensors - Will this always throw a code when bad or a CEL? Any Help would be greatly appreciated. I love this car more then anything its my pride and joy and I'm running out of options and money I really don't want to sell it.
3rd Gear
Joined: Sep 2006
Posts: 2,738
From: Holland MI
That is a sorry story and a lot of $$. Think back -- did you have any service just before you started to experience power loss? Can we correlate it to a change you made on the car?
Secondly, it sounds like sometimes you have power and sometimes you do not. How closely does it tie to a) the car being cold or hot, b) whether it has rained?
Is it blowing any unusual smoke from the exhaust? I'm wondering if you have a failing turbo, although I would tend to think it would work until it fails. I think one of the signs is that it starts leaking oil into the intake, which is why I asked about exhaust color.
You replaced the diverter valve and the vacuum hoses. What about the throttle body boot (TBB)? If you haven't chipped the car, you are not as much at risk but it may still cause similar problems (anyone else here?).
What do you mean by a diesel noise? Does the car get loud or knock....or do the rpms go way up but the car does not move. If the latter and an MT6, you could have a clutch problem. When my clutch started slipping, I was making all kinds of power and rpm but barely moving.
Last, the ABS/ESP should only affect braking, not engine speed/accleration. As I understand it, when the car deteces wheel spin it applies brakes to bring it back under control. Your CA start should not be related to that -- I sometimes do the same thing late at night and never had any ABS/ESP activity due to accelerating in 2nd at low rpms.
Secondly, it sounds like sometimes you have power and sometimes you do not. How closely does it tie to a) the car being cold or hot, b) whether it has rained?
Is it blowing any unusual smoke from the exhaust? I'm wondering if you have a failing turbo, although I would tend to think it would work until it fails. I think one of the signs is that it starts leaking oil into the intake, which is why I asked about exhaust color.
You replaced the diverter valve and the vacuum hoses. What about the throttle body boot (TBB)? If you haven't chipped the car, you are not as much at risk but it may still cause similar problems (anyone else here?).
What do you mean by a diesel noise? Does the car get loud or knock....or do the rpms go way up but the car does not move. If the latter and an MT6, you could have a clutch problem. When my clutch started slipping, I was making all kinds of power and rpm but barely moving.
Last, the ABS/ESP should only affect braking, not engine speed/accleration. As I understand it, when the car deteces wheel spin it applies brakes to bring it back under control. Your CA start should not be related to that -- I sometimes do the same thing late at night and never had any ABS/ESP activity due to accelerating in 2nd at low rpms.
Thread Starter
|
1st Gear
Joined: Mar 2009
Posts: 30
Formula - I decided to check all of my intercooler hoses. I think I'm on to something inside the hoses there is a lot of oil it seems like. Its a very thick and black liquid substance and looks dirty also. I'm not sure what this could be is this normal? It dosent look like it. What do you guys think? As far as TBB its on nice and tight, DV installed correctly and the car is running at normal Temp.
Faster4 - Yes plugs are gaped right I've rechecked them just to make sure and they are.
PPgoal - I dont think the problem began after any sort of change, and I've never really done any big changes to the car other then regular services like oil changes and stuff.
When it comes to heat it is kind of random as well, sometimes will run great in the morning while cold and somtimes when hot. However if on a trip longer then an hour it will get worse.
I actually did change th TBB too, thats actually the main reason why I bought the kit in the first place. And no no crazy RPM jumps or clutch slipping Engine just will sound like it is working real hard at lower gears.
Faster4 - Yes plugs are gaped right I've rechecked them just to make sure and they are.
PPgoal - I dont think the problem began after any sort of change, and I've never really done any big changes to the car other then regular services like oil changes and stuff.
When it comes to heat it is kind of random as well, sometimes will run great in the morning while cold and somtimes when hot. However if on a trip longer then an hour it will get worse.
I actually did change th TBB too, thats actually the main reason why I bought the kit in the first place. And no no crazy RPM jumps or clutch slipping Engine just will sound like it is working real hard at lower gears.
1st Gear
Joined: Jun 2009
Posts: 8
I have a 2.7t with close to 97k mi stick. Changed clutch at 86k but there is a strange liquid oozing out around the shifter and at first I thought it was just the leather covering around it melting due to heat or something.
I have no problem shifting gears but sometimes (rare) when I want to shift to reverse, its not smooth and I have to go to first and then put it in reverse. And yes, I do use the clutch well and engage it all the way and shift correctly without abusing it or overworking the engine.
Anyone know if this is a Boost leak or some other known leak? I have never worked on cars and always took it to Audi and they took care of things at a fancy rate. I also recently had a "minor service" and brakes done at 93k. Not sure what this could be and I was wondering if anyone faced a similar problem?
I have no problem shifting gears but sometimes (rare) when I want to shift to reverse, its not smooth and I have to go to first and then put it in reverse. And yes, I do use the clutch well and engage it all the way and shift correctly without abusing it or overworking the engine.
Anyone know if this is a Boost leak or some other known leak? I have never worked on cars and always took it to Audi and they took care of things at a fancy rate. I also recently had a "minor service" and brakes done at 93k. Not sure what this could be and I was wondering if anyone faced a similar problem?
1st Gear
Joined: Nov 2007
Posts: 45
From:
A couple of things come to mind:
1)What octane rating are you using? Try a tank of 93 and see if it makes a difference.
2)Exhaust system blockage. I have heard that when/if a catalytic converter wheres out, the material inside can cause a blockage, which will cause it to run very poorly. Not sure if the computer would throw a code when this happens or not.
1)What octane rating are you using? Try a tank of 93 and see if it makes a difference.
2)Exhaust system blockage. I have heard that when/if a catalytic converter wheres out, the material inside can cause a blockage, which will cause it to run very poorly. Not sure if the computer would throw a code when this happens or not.
Thread Starter
|
1st Gear
Joined: Mar 2009
Posts: 30
Update: Thought problem was solved by replacing the boost sensor on the tbb, but it wasn't. After much diagnosing I think the problem is carbon build up around the wastegate flap on my left turbo.
Last edited by N1a6Germ; Oct 6, 2010 at 01:01 AM.