I was driving on a long trip on the highway today, cruising in the left lane, switched to right, was in 5th gear, got in right lane and floored the pedal to pass the car in front of me when all of a sudden i feel a large thump from the engine, and then all of a sudden i was revving high. It was a really hard thump too, the kind of thump when you're driving an auto that shifts rough and you floor it hard while in overdrive. I really hate to think there's something wrong with my engine but I've never had something like that happen in all the years ive been driving a stick. Can anyone tell me whats going on?

All you are gonna get is suggestions over the internet. If you think there is something wrong, take it to the dealer.

I agree, have it checked out. If it still runs take it in, sounds ... not good.

Did you post this in another thread?
How do you guys drive your sticks. I'm rather lazy with it. I do things like skipping gears all the time.. for example I'll take off from a stoplight, rev 2nd all the way up to 4000+ RPM and then go right to 5th. Or when I downshift I'll go from 5th to 2nd. I skip around with gears all the time.

Maybe this has something to do with it?

Problem is, it only did that once on the way up and it ran perfect the rest of the way and on the way down. I dont want to bring it to a mechanic where they ask me what happened and then it doesnt do it - they'll just say well if it does it agian bring it back.

I just want to know what happened. What could've possibly caused this to occur?

ORIGINAL: Unbound

Did you post this in another thread?
How do you guys drive your sticks. I'm rather lazy with it. I do things like skipping gears all the time.. for example I'll take off from a stoplight, rev 2nd all the way up to 4000+ RPM and then go right to 5th. Or when I downshift I'll go from 5th to 2nd. I skip around with gears all the time.

Maybe this has something to do with it?


Has nothing to do with it, I was locked in 5th gear when it happened. All I did was floor my pedal to accelerate, then the thump occured, and I was revving high and it went back down. The clutch was never disengaged once during this entire event.

Hmmmmmm, well if it happens again take it in to get checked out.
I'm off to bed.
JL

ORIGINAL: XtacY

Has nothing to do with it, I was locked in 5th gear when it happened. All I did was floor my pedal to accelerate, then the thump occured, and I was revving high and it went back down. The clutch was never disengaged once during this entire event.


Depending on how fast you were going, the thump could have been detonation due to your lugging the motor. It's best to downshift if you're going to floor it unless you're doing over 70 already. Listen to your motor carefully the next few days and see if you hear any other clattering or knocking from under the hood, you may have gotten some bad gas too.

ORIGINAL: XtacY

ORIGINAL: Unbound

Did you post this in another thread?
How do you guys drive your sticks. I'm rather lazy with it. I do things like skipping gears all the time.. for example I'll take off from a stoplight, rev 2nd all the way up to 4000+ RPM and then go right to 5th. Or when I downshift I'll go from 5th to 2nd. I skip around with gears all the time.

Maybe this has something to do with it?


Has nothing to do with it, I was locked in 5th gear when it happened. All I did was floor my pedal to accelerate, then the thump occured, and I was revving high and it went back down. The clutch was never disengaged once during this entire event.


if you downshift from 5th to 2nd and a remotely regular basis...that has everything to do with it. Please tell me you don't seriously do that...

Sounds like it popped out of gear or into gear. If it stayed in gear, the gears and synchros were probably half way in and with vibration of engine it disengaged temporarily until rpms matched synchros and it fell into place again. Sounds weird but happens, and if it happens again have it checked, shifter maybe loose or forks in tranny too.[sm=icon_rock.gif]

OK... lol... I'm really just about done with my "TSB 06-9-9 Bandwagon" since my car has now been fixed.... BUT.... This "might possibly" be the problem. The symptom is described as a "hesitation upon acceleration after a long highway cruise". Typically this occurs after a long cruise (say 30-40 miles or more) and then exiting a freeway, coming to a stop and having your car engine just stop for a moment as you begin to accelerate.. and then it picks up and keeps going and acts totally normal throughout all other driving experiences, even repeats of that condition may not make it happen again... but it can and will under those circumstances if your fuel pump is one that is getting air bubles built up in over a long highway drive.

Now, here is where you come in and why I spoke up... the very first time this symptom happened to me was after driving on the highway about 60 miles or more and then kicking it into passing gear (ok.. dropping it into 4th by flooring it, etc.)... For all practical intents and purposes, that act IS an acceleration after a long highway cruise and my engine just sort of gave out for a moment with a bit of a thud (but not much) and then it picked back up again reving high (mine is an automatic though and the high rev had to be that it had dropped to 4th gear - and I had left my foot in the gas when it briefly gave out on me).

I dunno man, but if you experience a similar symptom again after driving a long cruise at highway speeds.... this may very well be your problem. It IS hard to replicate.

I had something fairly similar happen after I got off the highway to get some gas. After I started the car back up and started to drive off in 1st, I heard a loud thud and the car actually came out of gear...I was worried, but I haven't had an issue since...actually, why am I posting this, I don't think this helps any :)

ORIGINAL: 8cd03gro

ORIGINAL: XtacY

ORIGINAL: Unbound

Did you post this in another thread?
How do you guys drive your sticks. I'm rather lazy with it. I do things like skipping gears all the time.. for example I'll take off from a stoplight, rev 2nd all the way up to 4000+ RPM and then go right to 5th. Or when I downshift I'll go from 5th to 2nd. I skip around with gears all the time.

Maybe this has something to do with it?


Has nothing to do with it, I was locked in 5th gear when it happened. All I did was floor my pedal to accelerate, then the thump occured, and I was revving high and it went back down. The clutch was never disengaged once during this entire event.


if you downshift from 5th to 2nd and a remotely regular basis...that has everything to do with it. Please tell me you don't seriously do that...


Yep I do. Well it normally happens like this - stop light is coming up and I'm in 5th going 55 MPH. I put it in neutral and start hitting the brakes till about 45 MPH, and then I shift into 2nd to have the engine compression slow me down further. I do this for extended brake life more than anything. Usually when shifting into second here my car revs up to about 3500-4000 RPM and quickly comes down. I don't see how this is a problem at all being that if you floor an automatic really hard it commonly shifts into a lower gear that revs you around 3500+.

In the old days it was called VAPOR LOCK, back then you ran a cool can or wrapped the fuel line in aluminum foil to keep heat off the fuel line, thus stopping the vaporization of the fuel. But the vehicles never did the same as Xtacys car did, and thru the forum, the cars stall and restart or calm down at lower rpm after the vapors are released into fuel stream, so I don't know if it is the fuel pump, also we don't know the year or month of mfg. of his car to see if it falls into the fuel pump category for recall. I believe it was for earlier 05 stangs.[sm=icon_rock.gif]

Dude, putting it in second at 45 is a bit high, if you dont match your RPMs properly...Try third then second.
And if you downshift like this to save your brakes...dont....Brakes are cheaper and easier to fix than to fix a transmission.

The TSB I referred to in this case is for '05 & '06 stangaroos (V6 & GT). I am however "assuming" that this issue involves an '05 or '06 only cuz of the forum this thread is in. If it's a pre-'05er..... I have no clue. :)

It's an 05 and I bought it in May of last year.

i have a question. I have an '07 V8 automatic Vert that I believe shifts differently from the 2 other V8 test drive vehicles i drove (i did drive this car when it arrived but i didn't notice this issue then). When starting from a stop, i have to depress the peddle fairly far to get the car going and it seems to hesitate a bit and then "jump". When driving locally (no highway) i keep the O/D off and this appears to help slightly with the starting issue. Also, the tranny "clunks" when put into park, reverse or drive...not all the time, but mainly when it is cold. It is covered for 5 yr/60k, so i am less worried about this.

I know that there is a lot of torque, but this seems a bit off. Our other cars are a Honda and Nissan. The tranny's in both are a bit smoother, so that is my comparison. Any ideas?

i would hate to have my dealer start fooling around with my tranny. I already have an issue with with a bit of clean up work they did on the vehicle.

Thx

the auto trannys have alot of lag a tuner fixes that. Mine clunks too so i dont think its a problem

Thanks for the quick response.

Sorry, could you be more specific? Do you mean a tune up? I only have 850 miles on the thing!

ORIGINAL: XtacY

ORIGINAL: 8cd03gro

ORIGINAL: XtacY

ORIGINAL: Unbound

Did you post this in another thread?
How do you guys drive your sticks. I'm rather lazy with it. I do things like skipping gears all the time.. for example I'll take off from a stoplight, rev 2nd all the way up to 4000+ RPM and then go right to 5th. Or when I downshift I'll go from 5th to 2nd. I skip around with gears all the time.

Maybe this has something to do with it?


Has nothing to do with it, I was locked in 5th gear when it happened. All I did was floor my pedal to accelerate, then the thump occured, and I was revving high and it went back down. The clutch was never disengaged once during this entire event.


if you downshift from 5th to 2nd and a remotely regular basis...that has everything to do with it. Please tell me you don't seriously do that...


Yep I do. Well it normally happens like this - stop light is coming up and I'm in 5th going 55 MPH. I put it in neutral and start hitting the brakes till about 45 MPH, and then I shift into 2nd to have the engine compression slow me down further. I do this for extended brake life more than anything. Usually when shifting into second here my car revs up to about 3500-4000 RPM and quickly comes down. I don't see how this is a problem at all being that if you floor an automatic really hard it commonly shifts into a lower gear that revs you around 3500+.



the problem is, if you are downshifting into second and it is all the way up in 4k rpm's, that is going to wear your clutch out far faster than usual. If your clutch is burned up like an ass that would explain your problem.