2000 Mercury Cougar Mercury Cougar Bucking

I'm having the same problem. I have a 2000 Cougar with 85,000 miles on it. The car is fine at lower speeds but once I exceed 45 or so the car begins to buck. I haven't gotten it into the shop yet but I plan to in the next week or so. Please post if you find any solutions to the problem. I will let you know what I find out.

I am having the same problem. The codes read off for a egr valve. Well I went to the local advance and bought a egr valve that costed $63.00. Put it on cleaned out all the ports with carb and choke cleaner scrubbed them with a brush put the new one on and dang if it didnt start jerkin and shaking again. The only thing that I could come up with would maybe be the maf (mass air flow sensor) that would be causing the misfire. Let me know if you find out what it is.

I had the same problem with my Cougar bucking and hestitating and found out that there was a bad temperature sensor on my automatic transmission which caused the bucking problem after driving 10 or so miles. Once I had the sensor replaced, the problem ended. Unfortunately, only a Ford dealership with the diagnostic tools can find the code as I had to go to 2 other non-dealership shops who couldn't find the problem before going to the dealership and getting it diagnosed.

How much was the sensor and where did you get it at?

Sensor was about $50 but it was the labor cost that killed me from the dealership, about $350 because the sensor is in an inaccessible area. As I said, I went to the dealer to do a diagnostic as the other places I went to couldn't figure out the problem and didn't charge me for it. I might have had the same problem or maybe it is different from yours, but it solved my problem.

Well the problem that im having is it runs great until about 10 minutes down the road the rpm's will jump to about 4000 then kick back in which makes the car buck. Sometimes it runs fine, other times it does terrrible. Its mostly just above 45mph. Do you get the part from the mercury dealership or from the ford and cross refrence it with a ford contour?

Sounds like you had the same problem I had where I had the engine surging after it got hot. The dealer got the part for me and put it in. Since it uses the Duratec engine, probably same part as the Contour. The headache with both cars was that the really squeezed the engine into a small space compared to the space in the Taurus for the Duratec so that it is really difficult to do a swap and replace on the module hence the high labor.

I'm having the exact same problem. My car is currently in the shop and it read out a code for a bad mass air flow sensor. They're going to run some more tests to try and diagnose exactly what the problem is before they replace the mass air flow sensor which I believe costs around $300. I'll update when I get some more info.

I'm thankful I found you guys. I have a 1999 Cougar with 109,000 miles. I have done everything it has ever needed (which has been a lot), and lately it started jerking and choking at high speeds, going up hills, or passing other traffic. I took it to my normal garage the week before last and paid $1K which included new spark plugs, fuel filter, carbon cleaned out and some other small things. They said the problem was solved but I think it's even worse now. I went back last week and they found nothing wrong. I'm really frustrated with this car. Tonight on the way home my check engine light started flashing while the car was jerking so I figured the car was misfiring. I'm more than willing to have a temperature sensor put in if you really think that'll fix the problem. Please help.

I have a 2000 cougar with a 2.5l v6 with 246000km (approx 152,000 mi), I changed my plugs about 3 weeks and and within 2 days of changing my plugs my engine light came on. It is also blinking at me. I asked my machanic why my engine light would be flashing at me and with new plugs my my car would be hesitating. He told me it more than like a bad plug that was misfiring.

The problem is not with the motor its a sensor. This happened to my 2000 special edition cougar. Its a ''high range input sensor'' they run about 60dollars.

I have a 2000 mercury cougar which has been great up until now. This problem has been going on for a few weeks and no one seems to be able to solve it. After driving about ten miles when the car gets warm it begins to surge and buck. I first thought it was the transmission and took it in to be checked. They told me they thought it was and engine misfire. I took it to another shop and they replaced plugs, plug wires, o2 sensor, fuel filter, belt on the water pump. It is still doing the same thing. I have since been back to the transmission shop and they still believe it is and engine misfire. I know that the fuel pump on this car was recalled. Could that be causing this? Please help I don't know what else to do.[/Quote]

I got my cougar fixed. They replaced the MAF and also the MLP switch. I believe the MLP (manual lever position?) Switch tells the engine what gear it is in. At any rate the car stopped bucking. Thanks everybody for your help.

"High range input sensor"? Where is this located? I have a 2001 that is doing the same thing as other are describing. The only code coming up is a misfire. The plugs and wires have been replaced 25,000 miles ago.I don't think thats the problem.

I put a new coil pack in. Problem fixed!

The high range sensor was next to the batery onder some hoses. Ill send a pic of it later

Is this the "high range input sensor"?

Rallymedik
PostPosted: Fri Jun 06, 2008 1:24 pm Post subject:
I put a new coil pack in. Problem fixed!

I have been looking around this site to fix my wifes 2000 Cougar. I found this thread. I wanted to add some good accurate feedback.
Our 2000 Cougar was hesitating/buckling and never went over 4500 RPM. It started fine, ran fine, but when you accelerated, the problem became more apparent. This car has about 136k miles on it. I am not sure if the previous comments are accurate, My problem was fixed after I replaced the
"Transmission Range (TR) Sensor" I think I paid $56 for it. This verbage and picture attached is right out of the 2000 Mercury manual. It outlines the need for a special tool called a "TRS Alignment Tool" I did not get this tool, I used the manual I have online from Alldatadiy.com
This sensor monitors the position of your transmission. After installing it, it was a night/day difference immediately. It solved my problem.
The sensor is mounted on top of the transmission, mine is automatic. Just under the battery tray.

Now the car is hesitating when cold and light accelerating, I think it is the EGR valve or the DPFE senser (Differential Pressure) which is also a part of the EGR system.

Good Luck to all.

Dear amevolution did this solution fix your problem. My daughter has a 2001 with same problem. Thank you for a reply :)

Where can I get a transmission range sensor (high range inout sensor) for a Mercury Cougar?