Is my clutch going out?

[Skidzz]

Last night I went out to drive around to get my mind off of some woman problems, and something happened when I started driving the car hard. Under WOT, after about 4000 rpm's, it seemed like the car was hitting "flat spots" where it wasn't pulling at all. It would just kind of stop accelerating for a second and then start to pull again. At one point when this happened, I ran it up to about 5500 rpm's, and afterword, I smelled a burning smell. The car is not overheating, and there is no CEL. I thought it might be the fuel filter or something, until I smelled the burning smell. Now I think my clutch is slipping. What do you guys think?

 

[40th GT]

Was the elevation changing at all when you were hitting those flat spots?

 

[Skidzz]

No, it was on flat, straight pavement. Oh, and I checked it again today. It actually starts to do it above 3000 rpm's, and it does it in all gears.

 

[DerekStangGT]

did the engine continue to rev while the "flat spot" occured? if so, it may be a clutch. best way to tell is to drive up a steep hill at a low speed in 5th gear and go WOT. if the RPMs shoot up (like youre in nuetral) the clutch is slipping. honestly, from what you described, it sounds more like an electrical problem. almost like an intermittant short to ground in a MAP or MAF sensor, although you say there isnt a MIL on.

 

[Skidzz]

Yes, the engine continues to rev up during the "flat spots," but the car just kinds of quits accelerating. And no, no CEL.

 

[DerekStangGT]

Yes, the engine continues to rev up during the "flat spots," but the car just kinds of quits accelerating. And no, no CEL.

yup, sounds like a clutch. but try that test before you go out and buy a $400 clutch

 

[BennyBlown2v]

Sounds like a misfire. Clutch slip is typically linear and increases with RPM/load.

 

[dude496]

benny you definatly know your stuff, definatly know more than i do....just curious, he says he is flat spotting and it continues up through the rpms in all gears.....if he is misfiring, wouldn't he say his car is running rough or bucking? Also he said he smelt a burning smell.

Put your car in any gear, and give it gas...does itg rev up before you start going forward? Or does it feel like it is catching?

Also, can you explain what you mean by flat spotting? Is it that you lose power, but dont rev up....or is it that you lose power and revs up quick?

 

[Skidzz]

No, if it's in gear and I give it gas, it pulls immediately. By flat spotting, I mean it feels like I temporarily losing power for split seconds at a time. Yes, it is sort of like a slight "bucking." Also, when it does it, the rpm's don't really shoot up quickly during the flat spots, like it would in neutral. This makes me think it's not the clutch, but the burning smell still gets me. I have no idea what's going on.

 

[Skidzz]

Ok, so I just went out for a drive and here's what I noticed:

1. I did the "hill test." It's not the clutch. The clutch is holding fine in all gears.
2. I noticed that the car is bucking any time I cruise at about 2000 rmp's in any gear.
3. It's like the car is just losing power during these flat spots.

Maybe it is a misfire. I still can't tell.

 

[the98stang]

It sounds like a misfire. Change the plugs and gap them correctly

 

[thomas91169]

misfire.

if it was the clutch and you got on it in 3rd or 4th at youre peak torque point, and the rpm's just shoot upwards and the car does not accelerate, that would be the clutch. followed by a fishy pungent odor of burning clutch material.

sounds like youre timing was not advancing in those areas.

 

[Skidzz]

Ok, so do I just need to change the plugs? And if so, do I buy plugs for an '03 GT, since I have '03 heads, or are they the same? And do I need to gap them any differently than the stock specs?

 

[merc123]

Change the plugs and see if it fixes it. Might have to replace the coil pack. Also, check your plug wires, make sure they haven't worn through and might be rubbing on something.

 

[Skidzz]

Ok, but again, do I go with plugs for an '03 or the stock plugs, or are they the same? And what do I gap them for: '96 specs or '03 specs. Because, again, I have '03 PI heads.

 

[TripleBlk]

Last night I went out to drive around to get my mind off of some woman problems, and something happened when I started driving the car hard. Under WOT, after about 4000 rpm's, it seemed like the car was hitting "flat spots" where it wasn't pulling at all. It would just kind of stop accelerating for a second and then start to pull again. At one point when this happened, I ran it up to about 5500 rpm's, and afterword, I smelled a burning smell. The car is not overheating, and there is no CEL. I thought it might be the fuel filter or something, until I smelled the burning smell. Now I think my clutch is slipping. What do you guys think?

Here is the test. Put the car in 5th, and let up on the clutch. If the engine stalls, your clutch is OK.

 

[DerekStangGT]

Ok, but again, do I go with plugs for an '03 or the stock plugs, or are they the same? And what do I gap them for: '96 specs or '03 specs. Because, again, I have '03 PI heads.

i dont have the specs in front of me, but i would guess they would be the same.

as for the misfire, the thing is, there isnt a MIL on. usually when a misfire occurs, especially as often as you describe, a code is set for "misfire cylinder X" or at least a "random misfire" code.

Skidzz, you dont have MIL Eliminators for you X pipe, do you? im not sure, but they may keep the MIL off for all codes related to the cats. the burning you smell may be from excess fuel entering the catalytic converters, which would support the misfire theory. it would be easier if i could test drive it...

 

[Skidzz]

Well damn, I wonder what the hell is wrong with my car then. It's not the clutch, I've figured that much out, but there is no code being thrown. This doesn't make sense.

 

[DerekStangGT]

Well damn, I wonder what the hell is wrong with my car then. It's not the clutch, I've figured that much out, but there is no code being thrown. This doesn't make sense.

i hate to say it cuz most people hate them, but the dealership is your friend. im sure theyve seen 30 stangs with the same problem and could diag it in under 30 min.

just curious though, how old are your wires/plugs/cap/rotor?

 

[Skidzz]

If the plugs were changed when the PI swap was done, then the plugs and wires aren't even a year old. If the PI heads and NPI heads use the same plugs, then I doubt they were changed. Otherwise, they are the stock plugs/wires/coils. The car has 78k miles.