Contour Enthusiasts Group Archives Forums General Troubleshooting Request for help: Bucking that is less evident as rpms go up? More inside. Thanks!

Hello fellow CEG'rs. I have a problem with my car.
I own a 2000 Contour SVT with 6,800 miles. I have owned it 1 year now. I have done enough research on the forum to determine there is something wrong with my vehicle. The car bucks with mild to aggressive acceleration (throttle position)in all gears. It becomes less evident as rpms go up (so its less evident in the first 2 gears as they rev very fast), so as by mid-3000's, you can jump on it and not start "bucking", at least not noticably... It is very evident from idle rpms to mid-3000's rpms when one tries to be aggressive on the throttle. Another interesting comment is that when accelerating, and it's in 2nd gear, it revs fast enough not to linger in the rpms where bucking is evident, but if you gun the accelerator it almost seems to not have any effect on power - flat, almost a loss...

I have had this problem since when I first got the vehicle but I always thought it was something to do with a manual and gearing in relation to rpms but now I fully realize this is not the case.. This is my first time owning and driving a manual, hell even a new car, let alone a svt.

My research on the board has possibly yielded these items of possible cause:
Plugs / Wires / Fuel filter / TPS sensor / IAC motor / Inertia Fuel cut-off switch (unlikely) / Coil pack / O2. Maybe running lean under load? Maybe missing?

Would any of you knowledgable CEG'rs have any ideas or does this sound familiar at all? Any help would be greatly appreciated - I value the knowledge on here more so then the dealer. Thankyou in advance!

please don't jump to conclusions, you say this is your first manual transmission. And the STV has a very "tight" clutch.

Manual transmission differ very much. Mainly that the auto trans, are driven through a "buck dampening" hydraulic coupling [the torque converter] where the manual has nothing of the sort, when the clutch is engaged the only thing between the engine and tranny is a set of springs or rubber bumpers that prevent shock loading the crankshaft.

In other words, please don't be offended when I say this, but when reading your post I thought that it may be your driving habbits that are the problem, not the clutch or transmission. In any Manual transmission viehicle, if you straight up gun it suddenly it will buck. If you ease the gas pedal down it will not happen. This phenomenom does not occur with auto transmissions because the torque converter will "slip" when you floor it, (allow engine RPM to rise above tranny input shaft RPM) So instead of 'dropping the hammer' try easing the gas down, and go a little easier on the clutch and see if the problem goes away. Besides, it is better to drive smooth in the long run, your differential and clutch will last much longer.
-JSmith

BTW, bucking will be less when RPMs are up because the engine is able to overpower the surges that cause the buck and therefore you don't feel it as much.

These are only my thoughts on the matter, and possibly through the advice given by others who post you may find out that something actually is wrong.

Hello JSmith - thankyou for reading my post. In reply to you post - I can drive manual quite well, I have had over a year to practice and I took to manual like a fish to water. I am not a pro-racer, but I can feather in the clutch quite effectively to create a pleasant engagement. I love the tight clutch-action. I am quite fond of not letting off the throttle all the way as to allow easier engagement into the gear (by controlling my rpms). I never dump the clutch (when engaging the gear) without some feather as that would create a nasty buck (as you mentioned) All these symptoms are after clutch engagemet and when in the appropiate gear for the speed, etc etc.
Thanks!

TTT

Could an engine mount have gone?

Very possible, friend of mine 89 F-150, 5.0 v8 has a bad engine mount and it bucks like a pissed horse.

BlackP. sorry my advice is not something that would help. I just know that when I first started driving manual it took me a while to get the clutch engagement to where I could do it nice and smooth. Just offering a suggestion.

Same thing happened to me after driving a new 2000 svt. This particular car seemed to be running rich (small black cloud coming from rear exhaust upon startup and VERY sooty exhaust tips for 150 miles). I don't know whether or not this was the prob, but when I got my (slightly) used 98 svt, this bucking problem was not in evidence at all. I concluded that it was a problem specific to the car, and not just my driving habits.

Hope I helped, Sam

Four simple things to think about:

1) If the A/C is on, shut it OFF!!!

2) The secondaries kick in at 3,500 and the car will hesitate.

3) I have 53K miles, 0 problems and the exhaust tips are clean as a whistle.

4) What is your City vs. Highway driving ratio?

In support of BlackPantherSVT I would like to add that I have experienced similar problems. I've owned my car for almost 2 years with 23K now. I've been driving stick since I was 14(almost 9 years). In the RPM range 2000-3200 I experience slight bucking or hesitations at WOT. If I let off the gas slightly it smoothes a little and actually accelerates stronger than at WOT. I know this has nothing to do with it being an MTX. Over the years I've almost convinced myself that this must be normal but I just can't except that as fact when listening to others describe their driving experience. When I first bought the car I got as low as 14MPG. Now I average 22 with mixed city/hwy. However my tips do seem to be sooty not at all "clean as a whistle" as Rich in NH stated. So I guess what I'm saying is that you're not alone BlackPantherSVT.
I wish you luck and hopefully someone will come up with a solution to our problems.

Might want to try cleaning the throttle body if it has not been done yet.