Yes I have read most of the threads about the AFM issues but have one simple questions that I have not seen answered here. Not sure if there is really an answer:

Is it likely to still have trouble or a failure with AFM if I never let my 7 speed manual car go in to V4 mode (by never putting it in ECO mode)?

Is it recommended to let it go in to V4 mode every once in a while to avoid issues?

Not trying to open up the same old can of worms, just want to know what is best for my vehicle (and checkbook).

Thanks,

jeff

 

I purchased a 2019 C7 manual brand new and never had it in ECO Mode once. Lifter pitted and scored cam shaft. Replaced all lifters and cam shaft under warranty. Was this a result of never having it in ECO Mode? I don't think so. Just the AFM parts that can fail.

 

Thanks for the response driveswithtwofeet.

So after your experience I ask, if you had occasionally let it go in to V4 mode and "exercised" the parts would this have helped avoid your issue?

Thanks,

Jeff

 

Tuned it out in my M7. I believe more of the problem is with Autos as they go in and out of V4 unless you are set in manual mode. Also some say the DOD also can cause some shudder in the autos.

 

bottom line is the springs in the dod lifters are weak and prone to fail. doesnt matter if you are full time v8 or part time. the question is how long are you willing to roll the bones?

 

Thanks for the replies all.

9sec I understand what you mean. So if my M7 has never had an issue and I don't want to roll the bones anymore, what all has to be replaced and approx how much does it cost on a car that has had NO issues so far. Also do you go to independent shop or dealer?

 

so to start understand I do all my own work so I cant comment on any shop other than most charge 125-175 per hr. as for what to replace the heads have to come off so its basically a top end tear down. may as well drop in a cam double springs pushrods and lifters. when it comes to lifters its also the trays that fail allowing the lifter to turn and wreck the cam. so I use link bar lifters and eliminate the tray . not cheap but very reliable. trunion kit for the rockers so the needle bearings dont fail. bigger cam for the chop and ad more fuel . I dont care for the phaser lockout on the cam so I do a complete vvt delete. no need to allow for advanced Tim ing the new cam is already a bump. collecting my parts from the forums from guys who bought parts and never installed them (all new in box) I have about 5k$ so far. guessing about 7k$ from a shop would guess another 5-7k$ in labor then tuning.
you could just pull the heads tune out the dod replace the lifters with some ls7 ls springs and pushrods and drop in a vvt cam from gpi or btr but seems a waste to me . if im going to get dirty I want to see the most bang for the buck. im forced induction so I see more of a hp bump than a n/a car will.

im sure theres someone out there with 100k on the motor and no issues from the afm/dod but to its a vette why would you want 4cyl in the first place!! I ran a range device from the day I got the car (14k miles) to approx 20k miles then had it tuned out when I tuned the bolt ons. will do a permanant delete when. I drop the motor this winter approx 25 miles by then . have had zero issues and may not see any wear at all when I tear it down but my goals are 750-800 wheel and I drag the car so im not taking any chances. this was about a yr of sourcing parts for my build. many more parts added since then.

 

Looking at your numbers, we are talking about $14K at this point. From past experience, mod bills never go as planned. Always higher, never lower. For that kind of money, I probably will go with a 378ci package from LPE making 600HP with a 3 year 36K warranty and be done with it. At least that caps the price and has a warranty and improved performance.

Looking at the BTR kit for $1600 and if we add a few thousand for labor and end up with a $5000 bill, it might be a better option unless it is a race situation like yours. If it isn't too wild, you can get itchy and decide to sell it easier and upgrade to a newer series.

Maybe the better question is "What is the statistical likelihood of hitting 100K without an AFM failure?". I don't get why people are so indignant about a vette in V4 mode when it isn't being used. If I can cruise comfortably at 70, it can go into V2 mode for all I care as long as I can get V8 on demand. I just got AFM tuned out to buy myself some time, as advised by a couple of speed shops till I decide what to do. Probably going to get a cam kit that isn't too far from stock since I really am not looking for a lumpy cam.