Specific rpm range problem
10-06-2014, 11:41 PM
#21
Audiworld Junior Member
Join Date: May 2014
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
Will chech engine light come in the panel ?
I had this symptoms when I need power to go up hill, and om highway, engine feel like only 3 cylinder is active. Not mutch power, and car is shaking. I have changed filters spark plugs But have no idea what it it's. The transtec company told is not converter, Can it be coils? Carbon buildup"? Would the diagnosis say what so is the main problem?
Symptoms are fairly constant. Hot or cold. Idle is stable and smooth in all other ranges except the range starting from 1200, it gets a vibration. The unstable fluctuation happens only when you try to hold the throttle at exactly 1400 rpm. Impossible to hold constant throttle at 1350 to 1450 rpm. Bounces 100 rpm in either direction. Hard to explain really.
In drive there is a small vibration as it accelerates through the 1400 rpm range. (Almost unnoticeable but clearly not normal). There is no surge like torque converter issues.
My suspicion is vacuume leak / clog or carbon deposits on valves.
In drive there is a small vibration as it accelerates through the 1400 rpm range. (Almost unnoticeable but clearly not normal). There is no surge like torque converter issues.
My suspicion is vacuume leak / clog or carbon deposits on valves.
10-12-2014, 09:25 PM
#22
Audiworld Junior Member
Thread Starter
Join Date: Sep 2014
Location: Vancouver
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
Finally got my chariot scanned with a genuine ross-tech vagcom. Some of the codes were definetly problems I had previously taken care of but we're still stored. The engine fault codes on the other hand are newer. Last happened on October 1st. i test the idle stability at 1400 rpm daily so wouldn't it show up as even more recent codes. Anyway maybe someone here can recognize a link between the codes (which I'll post) and the problem.
10-19-2014, 10:50 PM
#24
Audiworld Junior Member
Thread Starter
Join Date: Sep 2014
Location: Vancouver
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
If anyone is still interested. I've tried changing the map sensor as well this week. No change. Revs still hunting when I step on the pedal to 1400 rpm. Today I took apart the pcv valve ( crankcase breather) looked clean with a tiny slit in the diaphragm flex point, but nothing where it closes. And no hissing when engine is running. I should probably still change it though. Think the pcv could be a problem? Anyone else have issues with it? When the car is at idle and I open the oil filler cap it does make a funny noise coming from the pcv. Like a balloon letting out air slowly. I'll try and get the video up. Maybe someone can verify that their c6 does the same or whatever a healthy engine should do? Thanks guys.
10-26-2014, 11:59 PM
#26
Audiworld Junior Member
Join Date: May 2014
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
I diagnosed this weekend and the fault was coil cylinder nr 6 When i open it there was a small amount of water, condensed there, I pumped that out, and air pressure clean, the coil was not damage but i put in a new one. After motor 100% 😋. Have some ideas why it was wet there? Others. Fault code was Colin system, water leak. But I have no leak of water , and water cooling tank is on same level. Anyway im happy that is ok again, and not carbon build up, misfired, valves
Thread
Thread Starter
Forum
Replies
Last Post
DG@Alta
RS4 (B7 Platform) Discussion
13
05-02-2007 11:19 AM