Bad Injectors, wires, plug, valve spring
#1
Racer
Thread Starter
Bad Injectors, wires, plug, valve spring
OK, I started noticing a miss especially when cold at higher than normal acceleration, not quite WOT. After taking it in three times the mechanic finds 5 bad injectors, 2 bad plugs, 1 bad plug wire. Mechanic replaces them and takes it out for a test drive, and #7 cylinder valve spring breaks!!! The keepers on the spring kept the valve from dropping into the cylinder but now I have to wait for that part (the spring) to come in. He says that once the spring is replaced all will be well.
I'm worried that all the injectors weren't replaced and that other valve springs could be faulty too. The Dealers mechanic says that under warranty he can only replace what GM allows him to replace and thinks the spring is an isolated incident. Also, I can't have the old injectors or spring because he has to send them to GM for warranty reimbursement. What say you guys???
Oh, forgot to say: 2014 A6 Vert with 7200 miles on it. Driven more aggressively than some others do!
I'm worried that all the injectors weren't replaced and that other valve springs could be faulty too. The Dealers mechanic says that under warranty he can only replace what GM allows him to replace and thinks the spring is an isolated incident. Also, I can't have the old injectors or spring because he has to send them to GM for warranty reimbursement. What say you guys???
Oh, forgot to say: 2014 A6 Vert with 7200 miles on it. Driven more aggressively than some others do!
Last edited by dpb; 05-14-2015 at 10:23 PM. Reason: add car description
#2
Tech Contributor
Member Since: Jan 2006
Location: Saint Louis MO
Posts: 4,761
Likes: 0
Received 218 Likes
on
110 Posts
St. Jude Donor '14-'15
That's a hell of a lot of injectors to go bad, and even assuming the plugs were fouled, that doesn't explain a bad wire... This is a cacophony of issues happening all at once. Doesn't seem to have much correlation unless I'm thinking about this the wrong way.
If there were truly 5 bad injectors, and you're worried that they didn't replace them all, there will still be DTCs being thrown on the bad injectors. If you're worried that everything wasn't replaced as you were told, take it to another dealer, and have them read it in - you'll know if you still have an ongoing issue if there are persisting DTCs.
#3
Drifting
There is an extremely high probability that the injector, plugs and plug wire were incorrect diagnoses. I bet the broken spring was the only issue.
#4
Safety Car
#5
Moderator/Tech Contributor
Member Since: Jun 2001
Location: Jacksonville Florida BWO Dayton, Cincinnati, Bloomsbury NJ, Cincinnati
Posts: 18,179
Received 3,810 Likes
on
2,058 Posts
2015 C7 of the Year Finalist
#6
Tech Contributor
Member Since: Jan 2006
Location: Saint Louis MO
Posts: 4,761
Likes: 0
Received 218 Likes
on
110 Posts
St. Jude Donor '14-'15
What's sad about this is that the GDS2 DTC system makes it so bloody easy to identify issues with this platform... No clue how a tech could make that many assumptions without the papers to back it up, unless they were just making things up.
#7
Racer
Thread Starter
Follow Up
OK, I started noticing a miss especially when cold at higher than normal acceleration, not quite WOT. After taking it in three times the mechanic finds 5 bad injectors, 2 bad plugs, 1 bad plug wire. Mechanic replaces them and takes it out for a test drive, and #7 cylinder valve spring breaks!!! The keepers on the spring kept the valve from dropping into the cylinder but now I have to wait for that part (the spring) to come in. He says that once the spring is replaced all will be well.
I'm worried that all the injectors weren't replaced and that other valve springs could be faulty too. The Dealers mechanic says that under warranty he can only replace what GM allows him to replace and thinks the spring is an isolated incident. Also, I can't have the old injectors or spring because he has to send them to GM for warranty reimbursement. What say you guys???
Oh, forgot to say: 2014 A6 Vert with 7200 miles on it. Driven more aggressively than some others do!
I'm worried that all the injectors weren't replaced and that other valve springs could be faulty too. The Dealers mechanic says that under warranty he can only replace what GM allows him to replace and thinks the spring is an isolated incident. Also, I can't have the old injectors or spring because he has to send them to GM for warranty reimbursement. What say you guys???
Oh, forgot to say: 2014 A6 Vert with 7200 miles on it. Driven more aggressively than some others do!
#8
Safety Car
"unless they were just making things up" seems more like it
#9
Melting Slicks
Not trying to come across as acting as the resident tech expert but I’d have thought a broken valve spring would have resulted in damage to the top of the piston. Am I missing something here? Don
#10
Moderator/Tech Contributor
Member Since: Jun 2001
Location: Jacksonville Florida BWO Dayton, Cincinnati, Bloomsbury NJ, Cincinnati
Posts: 18,179
Received 3,810 Likes
on
2,058 Posts
2015 C7 of the Year Finalist
I believe that the "keepers" on the valve would keep it from drop down and coming in contact with the piston. The problem would be exhaust gas or intake mixture (depending on which spring broke). The broken spring might horse up the rocker, trunion, or something on top????
My $.02
Elmer
#11
Le Mans Master
Member Since: Aug 2005
Location: CA.
Posts: 5,255
Likes: 0
Received 281 Likes
on
258 Posts
St. Jude Donor '13-'14-'15
I agree with the others--seems like a mis diagnosed warranty failure--The broken spring can create or simulate other issues that are indeed false--- A broken valve spring can create "false misfires' backfiring etc--Normally they would think it's a secondary ignition failure-How they got to the point of failing injectors is beyond me---