2.7T Audi A6 starting problem when engine is warm
05-20-2015, 09:22 PM
#31
AudiWorld Newcomer
Join Date: May 2015
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
I have a 2001 Audi A6 2.7t Automatic with a starting issue. It happens every time when the car is warm and doesn't mattter on outside temp. I will drive it then go into the store for about 30 mins, I try to start it but just cranks for a long period 10-15 sec. It will start and run a little rough for about 5 secs then idle fine. I can turn off the car right away and try starting it again and it starts right away. I checked fuel pressure and it is within specs,I checked the injectors and they are not leaking.
No CEL and scanned car and no codes.Local Audi dealership has no ideas.
No CEL and scanned car and no codes.Local Audi dealership has no ideas.
05-20-2015, 09:28 PM
#33
AudiWorld Newcomer
Join Date: May 2015
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
I have a 2001 Audi A6 2.7t Automatic with a starting issue. It happens every time when the car is warm and doesn't mattter on outside temp. I will drive it then go into the store for about 30 mins, I try to start it but just cranks for a long period 10-15 sec. It will start and run a little rough for about 5 secs then idle fine. I can turn off the car right away and try starting it again and it starts right away. I checked fuel pressure and it is within specs,I checked the injectors and they are not leaking.
No CEL and scanned car and no codes.Local Audi dealership has no ideas.
No CEL and scanned car and no codes.Local Audi dealership has no ideas.
05-21-2015, 07:10 AM
#34
How was your problem resolved? Which part did you get replaced and how much was the cost? Please help. Audi dealer is asking for diagnosing and then advise. Diagnosing itself is $120 and then after that cost of repair is additional with labor. Please help that will save my time n money.
05-21-2015, 04:12 PM
#35
AudiWorld Newcomer
Join Date: May 2015
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
05-21-2015, 05:49 PM
#36
on 2.7T, the coolant temp sensor is known to do this. It's not an expensive part (should be around $12~15) and would suggest to start there first.
05-22-2015, 02:07 AM
#37
AudiWorld Member
Join Date: Dec 2014
Location: Norway
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
If you do decide to get a new CTS - a word of advice; Don't cheap out and get an aftermarket part. It is very unlikely to be a cheaper solution, as almost all the aftermarket ones will either give wrong readings, be DOA or fail quite fast. Thus, if it does work, its unlikely to last for long. Certain aftermarket parts will hold up just as well (or maybe even better) than OE parts - the coolant temperature sensor is not one of those things.
Beyond getting a fault code readout (might very well point towards your issue), I'd advice you to inspect your vacuum hoses and maybe clean your MAF sensor.
I've been experiencing almost identical issues (per description of sympthoms) since I bought my 2.4V6 - changed spider hose, two CTS's, plugs and all filters etc - didn't change my issue. Last week I pulled the MAF sensor (T20 seurity torx bit) and sprayed it well 3-4 times over 2-3 minutes with a residue-free electronics cleaner (let it dry afterwards), and taped up over a frayed section of the vacuum hose going to the fuel pressure regulator. It has not had warm starting issues for 4-5 days now. Its a bit early to say if it fixed the issue, but clearly worth looking at.
(Taping over vacuum lines/hoses is neither a good nor lasting fix, but it can be a temp fix if you don't have new hoses/lines at hand)
Beyond getting a fault code readout (might very well point towards your issue), I'd advice you to inspect your vacuum hoses and maybe clean your MAF sensor.
I've been experiencing almost identical issues (per description of sympthoms) since I bought my 2.4V6 - changed spider hose, two CTS's, plugs and all filters etc - didn't change my issue. Last week I pulled the MAF sensor (T20 seurity torx bit) and sprayed it well 3-4 times over 2-3 minutes with a residue-free electronics cleaner (let it dry afterwards), and taped up over a frayed section of the vacuum hose going to the fuel pressure regulator. It has not had warm starting issues for 4-5 days now. Its a bit early to say if it fixed the issue, but clearly worth looking at.
(Taping over vacuum lines/hoses is neither a good nor lasting fix, but it can be a temp fix if you don't have new hoses/lines at hand)
Last edited by pr0xZen; 05-22-2015 at 02:10 AM.
05-22-2015, 07:37 AM
#38
If you do decide to get a new CTS - a word of advice; Don't cheap out and get an aftermarket part. It is very unlikely to be a cheaper solution, as almost all the aftermarket ones will either give wrong readings, be DOA or fail quite fast. Thus, if it does work, its unlikely to last for long. Certain aftermarket parts will hold up just as well (or maybe even better) than OE parts - the coolant temperature sensor is not one of those things.
Beyond getting a fault code readout (might very well point towards your issue), I'd advice you to inspect your vacuum hoses and maybe clean your MAF sensor.
I've been experiencing almost identical issues (per description of sympthoms) since I bought my 2.4V6 - changed spider hose, two CTS's, plugs and all filters etc - didn't change my issue. Last week I pulled the MAF sensor (T20 seurity torx bit) and sprayed it well 3-4 times over 2-3 minutes with a residue-free electronics cleaner (let it dry afterwards), and taped up over a frayed section of the vacuum hose going to the fuel pressure regulator. It has not had warm starting issues for 4-5 days now. Its a bit early to say if it fixed the issue, but clearly worth looking at.
(Taping over vacuum lines/hoses is neither a good nor lasting fix, but it can be a temp fix if you don't have new hoses/lines at hand)
Beyond getting a fault code readout (might very well point towards your issue), I'd advice you to inspect your vacuum hoses and maybe clean your MAF sensor.
I've been experiencing almost identical issues (per description of sympthoms) since I bought my 2.4V6 - changed spider hose, two CTS's, plugs and all filters etc - didn't change my issue. Last week I pulled the MAF sensor (T20 seurity torx bit) and sprayed it well 3-4 times over 2-3 minutes with a residue-free electronics cleaner (let it dry afterwards), and taped up over a frayed section of the vacuum hose going to the fuel pressure regulator. It has not had warm starting issues for 4-5 days now. Its a bit early to say if it fixed the issue, but clearly worth looking at.
(Taping over vacuum lines/hoses is neither a good nor lasting fix, but it can be a temp fix if you don't have new hoses/lines at hand)
I do however agree with you regarding OEM CTS sensor. The cost I mentioned was from an Audi dealer at the time I bought it (years ago).
Last edited by tester123; 05-22-2015 at 07:39 AM.
05-22-2015, 08:30 AM
#39
AudiWorld Member
Join Date: Dec 2014
Location: Norway
Posts: 150
Likes: 0
Received 0 Likes
on
0 Posts
Yes, MAF should throw codes for too low/high voltage, implausible signal (?) etc. Wether or not there are some fault scenario where it doesn't throw a code, or a code that does not "stick", I don't know. I have no idea wether or not cleaning the sensor affected the issue in my case, I only know my sensor was somewhat gunky and black (no codes) before cleaning, and not afterwards. I did also (I can't come up with a decent excuse right now) manage to reconnect the MAF while the engine was running and it the engine instantly died. Cranking it after hooking everything up again, issue has not appeared since (yet).
Personally I'm leaning more towards my case being a leak in (or collapse of) the vacuum hose going to the fuel regulator. After all these years, these thin-walled rubber hoses start to disintegrate and go too soft - especially if there has been a clog/ significant ammounts of oil in the PCV system at some point - like a knackered vacuum jet pump. The outer cloth braiding of the hoses will offer some protection, but only from outer exposure. Once they go too soft, they're at risk of collapsing under vacuum, especially if theres a sharp bend (partial collapse).
I don't know where Jagjeetaudi lives, but some places are more expensive than others. There are also fake "OE" sensors going around. I got one at the Audi dealership 2 months ago in Norway, ~$65. But parts are really expensive here in general. YMMV.
Personally I'm leaning more towards my case being a leak in (or collapse of) the vacuum hose going to the fuel regulator. After all these years, these thin-walled rubber hoses start to disintegrate and go too soft - especially if there has been a clog/ significant ammounts of oil in the PCV system at some point - like a knackered vacuum jet pump. The outer cloth braiding of the hoses will offer some protection, but only from outer exposure. Once they go too soft, they're at risk of collapsing under vacuum, especially if theres a sharp bend (partial collapse).
I don't know where Jagjeetaudi lives, but some places are more expensive than others. There are also fake "OE" sensors going around. I got one at the Audi dealership 2 months ago in Norway, ~$65. But parts are really expensive here in general. YMMV.
05-23-2015, 10:47 PM
#40
AudiWorld Newcomer
Join Date: May 2015
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
Yes, MAF should throw codes for too low/high voltage, implausible signal (?) etc. Wether or not there are some fault scenario where it doesn't throw a code, or a code that does not "stick", I don't know. I have no idea wether or not cleaning the sensor affected the issue in my case, I only know my sensor was somewhat gunky and black (no codes) before cleaning, and not afterwards. I did also (I can't come up with a decent excuse right now) manage to reconnect the MAF while the engine was running and it the engine instantly died. Cranking it after hooking everything up again, issue has not appeared since (yet).
Personally I'm leaning more towards my case being a leak in (or collapse of) the vacuum hose going to the fuel regulator. After all these years, these thin-walled rubber hoses start to disintegrate and go too soft - especially if there has been a clog/ significant ammounts of oil in the PCV system at some point - like a knackered vacuum jet pump. The outer cloth braiding of the hoses will offer some protection, but only from outer exposure. Once they go too soft, they're at risk of collapsing under vacuum, especially if theres a sharp bend (partial collapse).
I don't know where Jagjeetaudi lives, but some places are more expensive than others. There are also fake "OE" sensors going around. I got one at the Audi dealership 2 months ago in Norway, ~$65. But parts are really expensive here in general. YMMV.
Personally I'm leaning more towards my case being a leak in (or collapse of) the vacuum hose going to the fuel regulator. After all these years, these thin-walled rubber hoses start to disintegrate and go too soft - especially if there has been a clog/ significant ammounts of oil in the PCV system at some point - like a knackered vacuum jet pump. The outer cloth braiding of the hoses will offer some protection, but only from outer exposure. Once they go too soft, they're at risk of collapsing under vacuum, especially if theres a sharp bend (partial collapse).
I don't know where Jagjeetaudi lives, but some places are more expensive than others. There are also fake "OE" sensors going around. I got one at the Audi dealership 2 months ago in Norway, ~$65. But parts are really expensive here in general. YMMV.