2007 Audi A6 3.2L Won't start properly in cold weather
01-24-2013, 07:15 PM
#11
AudiWorld Newcomer
Join Date: Jan 2013
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
I have an 2007 audi a6 and whenever it is cold in the morning the car takes extra effort to start but it doesn't start right away it shuts off midway starting and ill have to start it again and it will run fine. This issue is only in weather below freezing or at least 32 degrees Fahrenheit. Sometimes it will take more then two tries to start the car and when it doesn't start it just stays at the battery stage since the key was already turned. I am not sure what could be the issue i have new spark plugs new coolant flushed as well and i never checked the battery manually i am assuming it could be the battery but i have had no problems starting the car in ok weather. Any ideas what could be making the car not start the first two or three times in cold weather? It runs fine once it starts though.
All Audi injectors need a back pressure of 10 psi on the retern side to work properly when car is running its ok , when car stops there is a valve on the return fuel side that holds the pressure if this is clogged or dirty it leaks the pressure resulting in fuel pump having to pressure the return side before injectors fire properly , the fix is simple allow gas tank to drop to 1/4 full add two bottles of injector and fuel system cleaner into tank drive until almost empty and fill up you will find your starting issues gone , this works on gas and TDI , my Q7 was same a pig to start then after startup great all day until next morning , now after this treatment starts first time every time
01-24-2013, 08:08 PM
#12
AudiWorld Member
Join Date: Nov 2010
Posts: 567
Likes: 0
Received 0 Likes
on
0 Posts
All Audi injectors need a back pressure of 10 psi on the retern side to work properly when car is running its ok , when car stops there is a valve on the return fuel side that holds the pressure if this is clogged or dirty it leaks the pressure resulting in fuel pump having to pressure the return side before injectors fire properly , the fix is simple allow gas tank to drop to 1/4 full add two bottles of injector and fuel system cleaner into tank drive until almost empty and fill up you will find your starting issues gone , this works on gas and TDI , my Q7 was same a pig to start then after startup great all day until next morning , now after this treatment starts first time every time
01-25-2013, 08:26 AM
#13
AudiWorld Member
Join Date: May 2010
Posts: 281
Likes: 0
Received 0 Likes
on
0 Posts
All Audi injectors need a back pressure of 10 psi on the retern side to work properly when car is running its ok , when car stops there is a valve on the return fuel side that holds the pressure if this is clogged or dirty it leaks the pressure resulting in fuel pump having to pressure the return side before injectors fire properly , the fix is simple allow gas tank to drop to 1/4 full add two bottles of injector and fuel system cleaner into tank drive until almost empty and fill up you will find your starting issues gone , this works on gas and TDI , my Q7 was same a pig to start then after startup great all day until next morning , now after this treatment starts first time every time
Where is the valve on the return fuel side located?
01-28-2013, 01:01 AM
#14
AudiWorld Newcomer
Join Date: Jan 2013
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
01-31-2013, 08:17 PM
#16
As far as i know, when you open the driver's door on the C6, the fuel pump starts (i heard it) to pre-pressurize the system.
This is a very interesting coincidence, I was just coming here to start a thread on the same issue.
Mine might be a bit different though:
- checked carbon deposits - found some but minor
- if weather is above 40 it starts like new every time
- cold weather, starts and stalls after half second, needs a couple more cranks which is something I really hate doing. Once it starts i can shut it off and restarts just fine.
The idle is always fine after it starts, plenty of power, no issues when going in D.
I'll try the fuel injector cleaner, simple one.
Any other suggestions, highly appreciated!
This is a very interesting coincidence, I was just coming here to start a thread on the same issue.
Mine might be a bit different though:
- checked carbon deposits - found some but minor
- if weather is above 40 it starts like new every time
- cold weather, starts and stalls after half second, needs a couple more cranks which is something I really hate doing. Once it starts i can shut it off and restarts just fine.
The idle is always fine after it starts, plenty of power, no issues when going in D.
I'll try the fuel injector cleaner, simple one.
Any other suggestions, highly appreciated!
11-18-2014, 06:16 PM
#18
AudiWorld Member
It's Back
Now that it is cold again issue is back with multiple cold starts attempts and the occasional highlighted gear indicator causing trany limp mode. The injector cleaner trick did help last year but did not fully resolved it. Throttle body cleaning also helped but did not cure it for good. Has anyone solved this issue for good? Thanks in advance.
Thread
Thread Starter
Forum
Replies
Last Post
grogo21
Audi 100 / A6 (C4 Platform)
3
03-27-2010 07:36 PM
