Let me preface this by saying that I have driven diesels for 9 years including 7.3's, 6.0's and now the 6.4. Im used to driving them, I like them, I know how they act, etc.

I have only had the 6.4 for 3 days now but have driven 200 miles and something doesnt seem right. I havent floored it all the way but my general feeling is that my 6.0 was definitely faster. I tried telling myself that the quiet engine is just deceptive. And that may really be the case.

But here is what really scares me. For the first 60 feet this thing wont get out of its own way. I push the pedal like I normally would and it starts to move but it just wont get going. Once it rolls out a little bit it seems ok. So I thought maybe the 6.4 needs more initial pedal so I push it half way down. Again less than 10 pounds boost, rolls about 60 feet then suddenly takes off. The best way to describe this is turbo lag (which I thought this engine wasnt supposed to have) but it happens no matter how much or how little throttle I give it.

I got off the highway, had already forgotten about the lag, and came to a stop. I had to pull out in to traffic and the truck was real sluggish. Oops, I forgot to compensate for that as I pulled in front of traffic. Now I panic and keep giving it more and more gas but until I roll 60-100 feet or so it just wont get in a hurry. After a few seconds the boost jumps up and away it goes but not until I caused traffic to hit the brakes and cuss me. So as a test I stopped on a back road and played around with "launching" the truck. Doesnt seem to make much, if any, difference how much gas I give it, it just doesnt want to take off. If I build the boost while holding the brake it seems ok but thats the only way this thing will take off.

I plan to stop by the dealer tomorrow to test drive another truck on the lot and see how it compares but I would love to get feedback from you guys.

Sorry for the long post.

 

Beautiful truck!!! I did the same exact thing about a week after I got my F350, I hit the gas pedal and just kinda rolled out into traffic, receiving some unwanted gestures. After I got rolling and the boost came up it took off pretty surprisingly. I really love my truck, and I get compliments on it all the time, but a little extra bottom end grunt would make this an excellent truck.

 

My f350 got better after about 15k miles. when I first got the truck and hooked a trailer up. it would not move till I got on the gas pretty good, now when I let off the brake in gear with the same load it will start rolling. Things have gotten a little more broken in, I assume. It does still lag off the line when starting up a hill. If I floor it it will slowly move about 10ft then rip the tires loose if i don't let off.
PS Nice truck!

 

Thanks for the feedback (and compliments). I love this truck but this turbo lag problem really threw me off. I drove it just like I would my 6.0 and thought "whats wrong with this thing". Then I remembered all the advertising (and sale pitch) how the twin turbo design was supposed to eliminate the lag and make it feel like a gas motor when taking off. Hmmm?? I wonder if they have programmed the PCM this way to combat the MPG issues? I noticed this morning when taking off from a light, that just to keep up with everyone else I was having to really get on it. Once I am up to speed just regular throttle is fine.

I will be towing 10k pounds this weekend if it doesnt rain and Im looking forward to seeing how it acts with a trailer. From all the posts I have read here, that seems to be when this new truck really shines.

Any other feedback from anyone? Good or bad? Just trying to compare or maybe find a trend. Thanks again!!!

 

Thanks for the feedback (and compliments). I love this truck but this turbo lag problem really threw me off. I drove it just like I would my 6.0 and thought "whats wrong with this thing". Then I remembered all the advertising (and sale pitch) how the twin turbo design was supposed to eliminate the lag and make it feel like a gas motor when taking off. Hmmm?? I wonder if they have programmed the PCM this way to combat the MPG issues? I noticed this morning when taking off from a light, that just to keep up with everyone else I was having to really get on it. Once I am up to speed just regular throttle is fine.

I will be towing 10k pounds this weekend if it doesnt rain and Im looking forward to seeing how it acts with a trailer. From all the posts I have read here, that seems to be when this new truck really shines.

Any other feedback from anyone? Good or bad? Just trying to compare or maybe find a trend. Thanks again!!!

 

I've had mine for about the same as you... two days and I can say that my modded 7.3 definitely had more get-up-and-go off of the line. I was told by my neighbor that it gets better by the second oil change or so. I don't really notice the big power like I was used to, but I'm doing 80 MPH in no time and it feels like I'm going 30.

Time will tell.... but I can honestly say that I miss my 7.3 for many reasons. The interior alone on these 08's are worth it though.

 

Testing/comparing with another truck like it is the best idea. They do exhibit a "lag", but not turbo lag. It has to do with the electronic throttle control. I think it was designed to give some, but not all power on take-off so as to not overly stress the drive train especially under heavy load. Mine has some lag time,but not nearly like you described, so it's worth checking. Hope this helps.

 

Does not sound right. Almost sounds like it is taking off in third gear. A couple a weeks ago I made the mistake of putting in 3rd while starting off towing. When I took off on an uphill from a stop wondered why it wasn't pulling too well. When I got up the hill doing 40 mph noticed what I did. For comparisons trying running 0-60 times. Last year I made 3 runs with my watch and I believe the times were about 10.3 average for my 450. No turbo lag at all. Towing my 5ver off of traffic lights it has no problem keeping up with traffic comparison to what my V10 was. Rough idea what my 0-60 time towing, estimated 25 seconds, will have to try that sometime too.

 

Wanted to make an edit to my earlier post.... I drove 3 different 6.4's before I bought mine and they all felt the same no matter what (3.73 or 3.55, F350, F250, etc).

 

You guys should get your injectors checked. My truck will get my trailer moving without touching the pedal. I have no low end lag at all.

 

I've drove a few. They all did it. It is a pain when you try to pull out into traffic.

 

Mine has no issues pulling my 5th wheel toy hauler loaded to about 14k. She will get herself and the trailer moving without hitting the fuel pedal. I have noticed that now that I have almost 14k on the odometer, the power does seem to be getting better though. I think as she breaks in more and more, it just keeps getting better and better. I dont remember mine having the issue you seem to be having though. It can't hurt to have her looked at though.

 

Like one poster stated, I have also heard the issue originating with the Electronic Throttle Control. I think that could be right OR it might be a transmission quirk. I know that mine is a little laggy, not as bad as your issue, but sometimes, it gets up and goes like a scalded dog. What's up with that? I was thinking that the transmission learning system was adjusting, but maybe a faulty ETC is the problem?

 

mine had really bad lag! to the point of almost getting hit many times. The new V10 is much better, but does not have that mid range power like the 6.4 had.

My 6.4 was really bad in the rain barely would move, then stubbled real bad.

 

I remember reading a review of the Big 3's 08 trucks, they said that the 6.4 has a lot of power, but you can't be afraid of pushing the pedal.