$projecthp
  • significant performance issue
  • significant performance issue
  • significant performance issue
  • significant performance issue

Thanks Thanks:  0
Likes Likes:  0
Dislikes Dislikes:  0
Results 1 to 5 of 5
  1. #1
    New Member
    Join Date
    Aug 2016
    Location
    st charles
    Posts
    1
    Corvette(s)
    cy z06
    Post Thanks / Like
    Rides
    0

    Default significant performance issue

    I have a 2015 C7 ZO6. I've had it for a year. The last several months I have noticed significant power loss after the car is warmed up and at track event. In the morning after the car is initially warms it accelerates perfectly fine there is no hesitation off the line. But after driving for awhile I noticed that off the line performance is extremely bad very slow until it reaches 3000 RPM. Very significant after my last drive from Chicago to st. Louis stopping at a toll booth and accelerating from the toll booth the engine was very sluggish up until 3000 RPM and then it surged rapidly. I also had several occasions where the car wouldn't have to the red line in 4th gear going hundred miles an hour and just kind of got stuck at about 4500 p.m. . This car has 650 horsepower and 650 foot pounds of torque and should not act like this. I had trouble barely passing a stock Mustang GT. At Road America last year with the temperatures within 90 days at the end of the straightaway I managed to get close to 150 miles per hour. This year when the temperatures were in the seventies on several runs I could barely make it to 108 and wouldn't go any further. There was one occasion about a month or two before this, racing down the highway around midnight and the check engine lights were flashing and there was significant notice for loss of power. The off-the-line performance is quite noticeable as I said even with the traction control and stability control turned off so this is not the case of the traction control kicking in. The car also does not appear to respond at highway speeds when accelerating in 3rd or 4th gear, there appears to be a very slight hesitation for about a second before I feel the power. There's also a horsepower gauge on the dashboard which when a car runs normal will go all the way to the 650 horsepower mark when floored. But when I was having these troubles I noticed a horsepower jump to maybe 375 fluctuated a bit and drop down to about 350 with the car floored in 3rd or 4th gear. When I took the car to the dealer he test drove it for 3 or so days and said It felt normal and the codes that were stored when the check engine light was flashing were erased already. I am thinking something to do with the fuel delivery system, the supercharger, or a restriction somehow in the exhaust. Any ideas before I take it back to the dealer and tell them to fix this thing. Apparently if therer are comp. codes, everything is fine according to them. By the way there was no overheating issues the car was running anywhere between 222-250-280 on the very hot 90 degree plus summer days last year. The other instances were at night when the temperature was in the 70s with clearly no problems with too high engine temperatures.





  2. #2
    Member LLC5's Avatar
    Join Date
    Sep 2004
    Location
    Wa.
    Posts
    2,299
    Corvette(s)
    98 black 6spd convert.
    Post Thanks / Like
    Rides
    0

    Default

    Quote Originally Posted by Mark Rolnick View Post
    I have a 2015 C7 ZO6. I've had it for a year. The last several months I have noticed significant power loss after the car is warmed up and at track event. In the morning after the car is initially warms it accelerates perfectly fine there is no hesitation off the line. But after driving for awhile I noticed that off the line performance is extremely bad very slow until it reaches 3000 RPM. Very significant after my last drive from Chicago to st. Louis stopping at a toll booth and accelerating from the toll booth the engine was very sluggish up until 3000 RPM and then it surged rapidly. I also had several occasions where the car wouldn't have to the red line in 4th gear going hundred miles an hour and just kind of got stuck at about 4500 p.m. . This car has 650 horsepower and 650 foot pounds of torque and should not act like this. I had trouble barely passing a stock Mustang GT. At Road America last year with the temperatures within 90 days at the end of the straightaway I managed to get close to 150 miles per hour. This year when the temperatures were in the seventies on several runs I could barely make it to 108 and wouldn't go any further. There was one occasion about a month or two before this, racing down the highway around midnight and the check engine lights were flashing and there was significant notice for loss of power. The off-the-line performance is quite noticeable as I said even with the traction control and stability control turned off so this is not the case of the traction control kicking in. The car also does not appear to respond at highway speeds when accelerating in 3rd or 4th gear, there appears to be a very slight hesitation for about a second before I feel the power. There's also a horsepower gauge on the dashboard which when a car runs normal will go all the way to the 650 horsepower mark when floored. But when I was having these troubles I noticed a horsepower jump to maybe 375 fluctuated a bit and drop down to about 350 with the car floored in 3rd or 4th gear. When I took the car to the dealer he test drove it for 3 or so days and said It felt normal and the codes that were stored when the check engine light was flashing were erased already. I am thinking something to do with the fuel delivery system, the supercharger, or a restriction somehow in the exhaust. Any ideas before I take it back to the dealer and tell them to fix this thing. Apparently if therer are comp. codes, everything is fine according to them. By the way there was no overheating issues the car was running anywhere between 222-250-280 on the very hot 90 degree plus summer days last year. The other instances were at night when the temperature was in the 70s with clearly no problems with too high engine temperatures.






    If the check engine light flashes at you, that means to pull over and stop, something is seriously wrong.

    Coolant temp at 250-280*F is too high, you need to figure out why.

    If you are still under warranty let the dealer figure it out, if the check engine light is or has been on there will be stored codes in the PCM to guide someone in the right direction.
    Master Technician

    25+ year ASE Master Certified Tech

    22+ year Honda Master Tech

  3. #3
    Member
    Join Date
    Jul 2001
    Location
    Vacaville, ca, usa
    Posts
    105
    Corvette(s)
    2019 ZR1 Blade Silver Metalic
    Post Thanks / Like
    Rides
    0

    Default

    Quote Originally Posted by LLC5 View Post
    If the check engine light flashes at you, that means to pull over and stop, something is seriously wrong.

    Coolant temp at 250-280*F is too high, you need to figure out why.

    If you are still under warranty let the dealer figure it out, if the check engine light is or has been on there will be stored codes in the PCM to guide someone in the right direction.


    Also remember that when the coolant temps get that high lets not forget that the vehicle's computer starts to pull timing from the engine and that contributes to the loss of power. I have seen it to many times at the track !

  4. #4
    Member LLC5's Avatar
    Join Date
    Sep 2004
    Location
    Wa.
    Posts
    2,299
    Corvette(s)
    98 black 6spd convert.
    Post Thanks / Like
    Rides
    0

    Default

    Quote Originally Posted by JOV View Post
    Also remember that when the coolant temps get that high lets not forget that the vehicle's computer starts to pull timing from the engine and that contributes to the loss of power. I have seen it to many times at the track !

    Yes it will, the PCM will do all it can to prevent any further damage.

    The flashing check engine light is telling you to shut down right now and is not something to ignore.
    Master Technician

    25+ year ASE Master Certified Tech

    22+ year Honda Master Tech

  5. #5
    Member LT4CE's Avatar
    Join Date
    Feb 2010
    Location
    Northern California
    Posts
    168
    Corvette(s)
    1996 LT4 CE
    Post Thanks / Like
    Rides
    0

    Default

    Quote Originally Posted by Mark Rolnick View Post
    When I took the car to the dealer he test drove it for 3 or so days and said It felt normal and the codes that were stored when the check engine light was flashing were erased already.



    Is it just me, or does the fact that the dealer said the codes were "erased already", sound fishy? I thought the codes stayed, until they were explicitly erased? OP didn't mention clearing them.

    Plus, why would the dealer need to drive it for three days?

    Maybe the OP should try another dealer, if this one refuses to address the problems?

Similar Threads

  1. Big cam issue??
    By Ricochett in forum C3 Technical and Performance
    Replies: 2
    Last Post: 12-30-11, 09:59 PM
  2. Transmission issue or non issue
    By Kenny in forum C4 Technical and Performance
    Replies: 6
    Last Post: 03-12-10, 01:03 PM
  3. GM Press Release: GM Announces Significant New Loan Financing As Low As 0% APR for Up To 60 Months
    By Rob in forum GM & Auto Industry News
    Replies: 0
    Last Post: 12-30-08, 06:32 PM
  4. GM Press Release: GM Announces Significant Production Cuts for Q1 '09
    By Rob in forum GM & Auto Industry News
    Replies: 0
    Last Post: 12-12-08, 04:13 PM
  5. Significant Judging System Changes
    By Rob in forum Factory Correct Resto. -- NCRS
    Replies: 0
    Last Post: 02-06-03, 09:18 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •