A5 8 Speed Tiptronic Problems
10-21-2020, 11:18 AM
#21
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Car doesent want to start
Few times when i start my audi a5 2011 8gears automatic , when i press the gas the car like doesent want to go , then after pressing the gas pedal its going normal , but on the taking off it has problems , it happened a few times to me , does anyone have that problem ? And how to resolve it
10-21-2020, 06:36 PM
#22
Start with a scan tool like VCDS to check for error codes. Then I would check the fluid level. It's probably a good idea to do a complete drain/fill (do it 3 times) of the ATF and replace the filter while you're at it. Reset the transmission computer to adapt to the new fluid/filter and check for driving problems. In your case, the symptoms sound like the either torque converter is not being filled up with ATF quick enough due to low fluid level or clogged filter, or the solenoids are a bit stuck due to the fine particles from the wear/tear of the gears/clutch packs. The cheapest fix is to put in fresh fluid with a new filter to allow maximum fluid flow and clear out the fine particles.
HOWEVER, if you have lots of miles (say 80K+ miles) and have never changed the fluid then don't change out the fluid. Your only choice is a new transmission since old fluid no longer protects and your clutch pack friction material has probably worn out and is floating in the fluid. Once you put in new fluid, the clutches won't engage correctly and you will have slippage issues. The design life of these transmissions is about 60 - 80K miles under normal driving conditions (just enough to go past the warranty).
The ZF 8HP transmission in the A5 is known to have shift issues at low speed with low thottle. It's not just an Audi problem. BMW and Chrysler owners have similar complaints. I have found that if you clean the intake valves and put some injector cleaners, the engines revs better, have more lower RPM response, and surprisingly, smoother shifting from the transmission. I believe the tranmission is programmed to expect a certain amount of torque from the engine at different RPM/shift points and as our engine gets gunked up with carbon deposit, the engine is not capable of supplying the required torque.
HOWEVER, if you have lots of miles (say 80K+ miles) and have never changed the fluid then don't change out the fluid. Your only choice is a new transmission since old fluid no longer protects and your clutch pack friction material has probably worn out and is floating in the fluid. Once you put in new fluid, the clutches won't engage correctly and you will have slippage issues. The design life of these transmissions is about 60 - 80K miles under normal driving conditions (just enough to go past the warranty).
The ZF 8HP transmission in the A5 is known to have shift issues at low speed with low thottle. It's not just an Audi problem. BMW and Chrysler owners have similar complaints. I have found that if you clean the intake valves and put some injector cleaners, the engines revs better, have more lower RPM response, and surprisingly, smoother shifting from the transmission. I believe the tranmission is programmed to expect a certain amount of torque from the engine at different RPM/shift points and as our engine gets gunked up with carbon deposit, the engine is not capable of supplying the required torque.
Last edited by findalex; 10-21-2020 at 06:50 PM.
10-21-2020, 09:41 PM
#23
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Start with a scan tool like VCDS to check for error codes. Then I would check the fluid level. It's probably a good idea to do a complete drain/fill (do it 3 times) of the ATF and replace the filter while you're at it. Reset the transmission computer to adapt to the new fluid/filter and check for driving problems. In your case, the symptoms sound like the either torque converter is not being filled up with ATF quick enough due to low fluid level or clogged filter, or the solenoids are a bit stuck due to the fine particles from the wear/tear of the gears/clutch packs. The cheapest fix is to put in fresh fluid with a new filter to allow maximum fluid flow and clear out the fine particles.
HOWEVER, if you have lots of miles (say 80K+ miles) and have never changed the fluid then don't change out the fluid. Your only choice is a new transmission since old fluid no longer protects and your clutch pack friction material has probably worn out and is floating in the fluid. Once you put in new fluid, the clutches won't engage correctly and you will have slippage issues. The design life of these transmissions is about 60 - 80K miles under normal driving conditions (just enough to go past the warranty).
The ZF 8HP transmission in the A5 is known to have shift issues at low speed with low thottle. It's not just an Audi problem. BMW and Chrysler owners have similar complaints. I have found that if you clean the intake valves and put some injector cleaners, the engines revs better, have more lower RPM response, and surprisingly, smoother shifting from the transmission. I believe the tranmission is programmed to expect a certain amount of torque from the engine at different RPM/shift points and as our engine gets gunked up with carbon deposit, the engine is not capable of supplying the required torque.
HOWEVER, if you have lots of miles (say 80K+ miles) and have never changed the fluid then don't change out the fluid. Your only choice is a new transmission since old fluid no longer protects and your clutch pack friction material has probably worn out and is floating in the fluid. Once you put in new fluid, the clutches won't engage correctly and you will have slippage issues. The design life of these transmissions is about 60 - 80K miles under normal driving conditions (just enough to go past the warranty).
The ZF 8HP transmission in the A5 is known to have shift issues at low speed with low thottle. It's not just an Audi problem. BMW and Chrysler owners have similar complaints. I have found that if you clean the intake valves and put some injector cleaners, the engines revs better, have more lower RPM response, and surprisingly, smoother shifting from the transmission. I believe the tranmission is programmed to expect a certain amount of torque from the engine at different RPM/shift points and as our engine gets gunked up with carbon deposit, the engine is not capable of supplying the required torque.
10-21-2020, 09:44 PM
#24
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Start with a scan tool like VCDS to check for error codes. Then I would check the fluid level. It's probably a good idea to do a complete drain/fill (do it 3 times) of the ATF and replace the filter while you're at it. Reset the transmission computer to adapt to the new fluid/filter and check for driving problems. In your case, the symptoms sound like the either torque converter is not being filled up with ATF quick enough due to low fluid level or clogged filter, or the solenoids are a bit stuck due to the fine particles from the wear/tear of the gears/clutch packs. The cheapest fix is to put in fresh fluid with a new filter to allow maximum fluid flow and clear out the fine particles.
HOWEVER, if you have lots of miles (say 80K+ miles) and have never changed the fluid then don't change out the fluid. Your only choice is a new transmission since old fluid no longer protects and your clutch pack friction material has probably worn out and is floating in the fluid. Once you put in new fluid, the clutches won't engage correctly and you will have slippage issues. The design life of these transmissions is about 60 - 80K miles under normal driving conditions (just enough to go past the warranty).
The ZF 8HP transmission in the A5 is known to have shift issues at low speed with low thottle. It's not just an Audi problem. BMW and Chrysler owners have similar complaints. I have found that if you clean the intake valves and put some injector cleaners, the engines revs better, have more lower RPM response, and surprisingly, smoother shifting from the transmission. I believe the tranmission is programmed to expect a certain amount of torque from the engine at different RPM/shift points and as our engine gets gunked up with carbon deposit, the engine is not capable of supplying the required torque.
HOWEVER, if you have lots of miles (say 80K+ miles) and have never changed the fluid then don't change out the fluid. Your only choice is a new transmission since old fluid no longer protects and your clutch pack friction material has probably worn out and is floating in the fluid. Once you put in new fluid, the clutches won't engage correctly and you will have slippage issues. The design life of these transmissions is about 60 - 80K miles under normal driving conditions (just enough to go past the warranty).
The ZF 8HP transmission in the A5 is known to have shift issues at low speed with low thottle. It's not just an Audi problem. BMW and Chrysler owners have similar complaints. I have found that if you clean the intake valves and put some injector cleaners, the engines revs better, have more lower RPM response, and surprisingly, smoother shifting from the transmission. I believe the tranmission is programmed to expect a certain amount of torque from the engine at different RPM/shift points and as our engine gets gunked up with carbon deposit, the engine is not capable of supplying the required torque.
10-22-2020, 01:44 PM
#25
Finally, if the transmission shifts fine after the engine's warmed it, it could also be related to carbon buildup. If the intake valves have lots of carbon builup, the valves can't close completely so it can't generate the power it needs to. As the engine warms up, the carbon softens and then the intake valves can seal the compression chamber completely, thus generating the correct power.
My A5 with the same ZF 8HP transmission also shifts a bit rough when cold (first 5 minutes). Things improved a lot after I added approximately 200 mL of ATF. I then used CRC Intake cleaner to clean my intake and that also improved the shifting when cold. Now my car has 91K+ miles on it, and I would say it shifts about 98% as smooth as when I purchased it new with 10 miles. Can't complain since these things were designed to only last 60 - 80K miles.
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