2000 Ford Taurus - HEAVY JERKING

hello to all experts here.
I have a 2000 Ford Taurus SES that jerks heavily after being driven for about 5 mins. She starts right up, idles well, runs well in the beginning but then suddenly will start jerking when pressing on the accelerator. I'll pull to the side, put the car on neutral and rev the engine a little to see if any hesitation - NONE. Then once I put it in drive again and step on the gas, it feels like the tranny or something is jerking and about to fall off. If I park it and turn the car off for a while, then return to it, start it and drive it, it'll run fine for a few minutes and then the problem will start again.
Please help!!!

Have you checked tranny fluid levels?

Is the deliverability of horse power , but not transmission?

If loss of HP with no DTC's, it could be as simple as a plugged catalytic converter.

If no, it's time for a new transmission fluid/ filter change.

Is the deliverability of horse power there, but not transmission?

If loss of HP with no DTC's, it could be as simple as a plugged catalytic converter.

If no, tt's time for a new fluid/ filter change.

To me it sounds like a fuel pump problem. When the car will not run squirt somme throttle body cleaner in the throttle body and see if it will run on it, if so a fuel delivery issue.
Get a cheap fuel pressure testing gauge (harbor frieght) and watch the fuel pressure when driving.

If loss of HP, it could make a good transmission look bad.
Random misfires on random cylinders -

Air - Bad or dirty air cleaner, MAF sensor, H20 sensor, unmetered air leaks on PCV, EGR, and air Intake systems.

Fuel - bad fuel filter, fuel pressure, fuel pump, fuel regulator

Ignition - Bad crank, or cam sensors.

Exhaust - Plugged cat or catalytic converters.

Welcome to the forum!

When's the last time the car's had a tune up? Your symptoms, as described in the original post, sound like a misfire due to worn plugs, bad spark plug wires, or possibly a vacuum leak.

-Rod

air filter is new, spark plugs are new, coil packs are good. If fuel delivery issue, I'd assume the problem will be constant whether the car is in park, neutral or in drive...correct? The problem, once it starts, is only when in drive and the accelerator is depressed. I've put the in neutral to see if there was any hesitation but NONE. Once i put the car in drive and try to drive, it jerks heavily. A key point here is that the problem begins after about 5 minutes of driving.

Car runs fine for the first 5 mins.
Car begins to jerk heavily after 5 mins of driving only while in drive and accelerator depressed.
Car put in neutral or park after problem starts does not show any hesitation.
Car put in drive and problem continues.

Thank you ALL. Please HELP!!

air filter is new, spark plugs are new

Were these items all changed in an attempt to fix this issue, or installed shortly before the issue started? Do you have access to a scan tool with datastream mode?

-Rod

It's really hard to tell the deliverability of the engine hp just by putting the car transmission in Neutral or parked position.

We want to see the hp @ the rear wheels, let's put a load on her by going up hill + pedal to the metal, hopefully this will be enough to throw a code.

thanks to all of you for the helpful tips. I've now derived at my brakes locking up as the culprit of my problem...I think? The rear brakes lock up intermittently...now the front brakes lockup after some minutes of driving. I've changed the two front brake calipers, the rear brake cylinders and still no avail. I noticed the front brakes unlock after letting the car rest for a couple of hours.
What could be making my brakes lockup? HELP PLEASE!!

I really doubt that brakes are reason for the symptoms you describe in the original post, but I suspect that there's a reason you are leaning that direction. Please share what you've recently discovered that caused you to look towards the brakes.

For what it's worth, if it were an intermittent brake lock up, I'd be looking more towards the rubber brake hoses than the calipers and wheel cylinders, but again, I really doubt brakes are causing the "heavy jerking".

-Rod

thanks Shorod. let's take out "intermittent" on this. I've tried repeatedly and found the front brakes to be locked up every time the problem begins. Once the problem begins, I quickly park the car, jack it up, and the the gear on neutral. I tried spinning each front wheel but both will not spin not even a mere turn. So the last time I tried, I left the car on the jack and switched the off. When i returned to the car after a couple of hours, the wheels spun easily and freely.
What could be the issue here?
thank you.

So I would assume then every time this happens it's after you've use the brakes a few times. Something is keeping the calipers and wheel cylinders from retracting. Since the calipers and wheel cylinders are new, about the only thing that could cause this would be rubber brake hoses that have collapsed and are now acting a bit like one-way valves, allowing fluid to be forced to the calipers/cylinders, but do not allow the fluid to freely flow back to the master cylinder (which is under much less pressure). I'd certainly suggest you carefully inspect the brakes first though to make sure the pads are wearing evenly and were installed correctly as well as checking the rear to confirm the shoes were installed correctly. Several drum brake setups use one shoe with "short" friction material and one with "long" friction material. Make sure both "long" shoes didn't get put on one side.

-Rod

you're correct Shorod. It begins to lockup gradually as I could feel it as the brakes begin to not release after multiple braking series. I drove to about 20/mph and let my foot off the gas pedal and the car literally came to a full stop as though I was the one braking. After which i began smelling the brake pads.
thank you very much.

Disconnect the vacuum hose to the brake booster and see if the problem occurs- don't forget to step hard on the pedal with no assist.

pardon my lack of knowledge but where's the brake booster located and what does it look like?
thank you.

The brake booster is the large drum like thing between the brake master cylinder (with the brake fluid reservoir) and the brake pedal assembly. It will be under the hood and the master cylinder is mounted to it. You can do a Google image search for "brake booster" to get a better idea what it looks like.

I'm curious where this is going though as I don't see how a brake booster issue could cause brakes to not retract. It could cause a hard pedal and it could cause a misfire due to vacuum leak, but stuck brakes?

-Rod

As you know, a brake booster has vacuum applied to both sides of a diaphragm, and when the pedal is applied, it opens a valve that vents the vacuum on one side, giving the asist. If that valve is sticky or doesn't close fully, it can apply the brakes slightly. Not a common failure, but did happen in the CV/GM/TC models in the 90's.

It sounds like the car needs some new rotors.

Since the jerking happens under acceleration, not braking, the issue is not likely to be brake rotors. When brake rotors have too much runout the jerking happens when applying the brakes, not when accelerating.

-Rod

Rod,
I thought you could use a Thanks for your patience with the newbies. He only has 3 posts and is picking a two year old entry to throw 2 cents at it that clearly don't apply. Keep dispensing your wisdom with kindness.
Randy

He's also from Iowa so I will cut him some slack. ;)

-Rod