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Mercury Cougar Engine Questions



  • I have a 1997 Mercury Cougar 4.6 engine. I am getting 2 trouble codes. (1) P0171 and (2)P0174. From what it tells me is that bank 1 and bank 2 are to lean. Can you tell me what cause's that and what I can do to fix it. Also I would like to know if these 2 codes will keep my car from passing an emissions test. Thank You for your time. John
  • Hi There, Was wondering if you ever found out the cause of your trouble codes P0171 (bank 1), P0174 (bank 2. I have the same codes on mine stating that both banks are running lean. Thank You John
  • Johnnie,
    mine is a 1999 Cougar (2.5l V6 auto). We had tons of error codes, and recently had "white smoke" and fouled spark plug, a strong sign for head gasket problems.

    We finally took everything aport, had both heads flow tested and planed, did a valve job. We also removed the "internals" of the pre-cat and installed the electronic dummy parts to fool the oxygen sensor.

    After everything is back together, it is working fine.

    Regarding the lean running: It was likely caused by a vacuum leak, possibly from not installing the seal of the upper intake manifold correctly when we had it off a long time ago.

    We also found a broken vac line which caused the vents to not operate (air only coming out of defrost nozzles). Shrink tube and electrical tape to connect the broken line fixed that, too.

    The only real problem left is now: the starter "grinds", it does not slip into the flywheel. We replaced starter about a year ago, but the problem soon came back.
    The only way to get it going is to switch gear into drive, then wiggle the car back and forth (in the hope to move the flywheel a bit to let the teeth of the starter engage).

    We are looking for a rigged solution to move the flywheel to allow the starter to engage. I don't think changing the starter will do any good. And changing the flywheel sound like a major job.

  • On my 89 I had no check engine light on and it passed smog with no problem
  • It sounds like your EGR valve is malfunctioning. It may be stuck. Do you know any one with a code reader capable of OBDI diagnostics?

  • Have the sparkplugs been changed? If so make sure they are platinum plugs and not regular resistor plugs
  • battery or alternator problem. check the battery because the same thing happens when the battery is disconnected
  • I have a 2002 cougar and the engine light is on. The code says egr. have replaced the egr valve, egr solenoid, egr pressure sensor, and the fuel cap. It still comes on after the code has been cleared. any suggestions? Thankyou in advance
  • PF_FlyerPF_Flyer Pennsylvania Furnace, PAPosts: 7,965
    I had a code indicated egr valve malfunction but it turned out not to be the valve itself but a leak in one of the lines connected to the valve.

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  • lmoreno3lmoreno3 Posts: 21
    Hey fellas, lmoreno3 here. I am still having the same problems with my sons cougar, As last posted. New radiator, new cap, new belts, new temperature sensor, put in a 160 degree thermostat(aftermarket). New water pump. Had it retested for any leaks. Holds pressure, no leaks. Had radiator and hoses checked with IR. All shows good. Seems water is flowing as it should. Temp gauge still shows hot after driving it for about 10 minutes at 70 mph or for 30 minutes driving at 35-40 mph, city driving. I have just bought a new aftermarket electrical water temp gauge, Exxus brand at O'Reilly's for 17.00 bucks. I am going to hook that one up and deaden the factory one. I want to see what the real water temp is. When I find out if it is overheating or not, I will post my results. Again, water does not boil in the resevoir, or boil out.

    Post results soon.

  • joevee1joevee1 Posts: 2
    OK...I don't know a thing about cars, but I am attempting to change the oil in a 2002 cougar. Where is the best place to put the jack ? ANd can anyone describe the oil pan and drain plug to me. I am seriouc, I really need help !!
  • lmoreno3lmoreno3 Posts: 21
    lmoreno3 here, finally installed the aftermarket water temperature gauge, here are my unfortunate results. The car still marked hot, but only after driving it for 25 miles. The first 12 miles, it did not mark hot, only went up to about 190 degrees, with the AC off. The last 13 miles, the AC was on Max, that is when the gauge went up to the Hot mark. Stopped and looked under the hood at the resevoir bottle, and the water was not boiling. No steam coming from anywhere under the hood, and no leaks. HELP!!! what else can I check and look for, I am at my wits end.
  • avp0713avp0713 Posts: 8
    lmoreno, sounds like your gauge is bad, OR you need to replace the resistor that is built into the fan assembly. It's a 50 dollar part. The dealership will charge 150 to replace it, but if you have simple tools, a good Jack, a blanket, you can do it yourself in 2 hours.

    I did it, I got under the car, pulled down the fan assembly just enought to remove and replace this resistor. Don't know the part number offhand, but I have it listed on the NECO Cougar forums.
  • lmoreno3lmoreno3 Posts: 21
    Am going to try that, had one of the three catalytic converters changed and that helped out, can go farther now, before it starts to show hot. Where did Ford/Mercury get the idea that three catalytic converters would be better?
  • Hi Imoreno3, Just getting to this site and don't know if you fixed your problem yet. I have experienced this problem in different vehicles and it turned out to be fan cooling problem. Cars with electric fans usually have 2 fans. When the temp reaches 200 degrees or there bouts the second fan should cut on. When you turn on your A/C it should also cut on. Cars with mechanical fans it usually turn out to be the fan clutch that is bad. Don't know if this helps but I know it can be a pain in the butt and usually the fix is a simple one. Sounds like you have already exhausted the difficult ones. Joe
  • lmoreno3lmoreno3 Posts: 21
    Thanx, for the info Joe, I will check on those pesky, have already checked the resistors and relays, and they are fine. But it can't hurt to get a second opinion from a good reliable mechanic that also does electrical work on cars, my sons cougar has the electric fans.
  • My mom and I have both owned cougars, hers a 99, mine a 2000.

    We have both experienced this problem. When she replaced the rear Catalytic Converter's this problem went away and she had more power than we could handle.

    however now as my car is doing the same thing, I got the rear converter replaced as well and the problem is NOT fixed yet. Unfortunately I am going to have to try getting the other ones out and see if that helps :S very expensive shop bill.

    Get this checked out on your car! It's a very common problem on cougars according to my mechanic.
  • I had to replace the engine block on my 99 Cougar. after getting it all back together, I am getting no spark. I replaced the ignition coil. Still no spark. The fuel pump is working, and I have checked all the fuses and sensors and modules, all appear ok. What could be causing this and how do I fix it so that my car will run.
  • ap2ap2 Posts: 1
    This morning i got in my car and was a bit cold so turned on my heater for a few min...turned it off when i warmed up...but noticed shortly later my car was not having that smooth engine flow but rather a chugging without the physical jerking of the car. Anyway shortly later check engine light comes on...drove it home no problem other then the fact that ocassionally that check engine light was now blinking . Turned car off and back on started no problem. LIght was not on till i turned around the corner and came back on...same issue...has anyone had this problem and can tell me what it is and how to fix it?
  • I have a 2000 Cougar with a V-6 that I have been having a problem with the head lights flickering, a/c blower motor surging and alternator light flickering. I ordered a new alt. and replaced my old one. I'm having the same problem although its a little better. With no load, it shows 14V. As soon as I load it up, the voltage jumps from 12 to 14 to even 16 or 18. I load tested the battery prior to replacing the alt. and it was fine. So, I removed and replaced the main wire off the alt. that feeds the batt. and still have the problem. I then, completely disconnected the wires at the alt. and I have no issues, problem fixed, but of course I cannot operate this car without an alternator. I think I may have a "bad" new alternator. Can someone confirm my suspicions or give any input to something I may have missed or not thought of. Thanks!
  • lmoreno3lmoreno3 Posts: 21
    I have 2000 Merc. Cougar, that the temp gauge shows it is overheating. When I check the resevoir bottle, the water is not boiling. I have replaced the radiator, water pump, coolant sensor, temp sensor, all of the belts, have flushed the engine, replaced the thermostat, even put in an aftermarket 160 degree. Still shows that it is overheating. I have also had the entire system pressure tested and it holds the pressure, so no leaks of any kind. Currently am running the car without a thermostat, but here is where it gets interesting.
    When I removed the thermostat, I noticed that the hose that it is attached to is not to the upper radiator hose, like it is supposed to be, but to the lower radiator hose. The upper radiator hose bypasses the thermostat housing and connects to the back of the thermostat housing. My understanding is that the thermostat is supposed to be facing the radiator, and attached to the upper hose. Is this an error made by Mercury. Has anyone else had this type of problem and been able to solve it or had someone solve it? Please, let me know. Thanx in advance for help and advice. :sick:
  • avp0713avp0713 Posts: 8
    It obvious that your dashboard temperature gauge is bad, perhaps experiencing an electrical short. Mine was doing the same thing (reading hot), finally I just "bopped" it with my fist on top of the dash, then the needle went to the center of the gauge and stayed for a while then while I wasn't looking, it went back to cold, then again, way up to the red. I plan to buy a aftermarket MECHANICAL (not electric or electronic) and install it. I'm not going to worry about the one in the dash. . .it's cheap and defective.
  • lmoreno3lmoreno3 Posts: 21
    Thanx for the info and advice. I went a purchased an Eqqus guage today, and am going to install it tomorrow. One more question though. Coming out of the water temperature sensor plug are two wires. One is green witha red stripe and the other is grey with a red stripe. The question is which one is the ground the green with the red stripe or the grey with the red stripe? I want to get this right the first time, since it is a tight fit to work in.
  • lmoreno3lmoreno3 Posts: 21
    I am going to rewire the water temperature sensor to the original gauge, is this a diffifult fix. I do not currently plan to cut off the wires, just splice the new ones on. I think my problems is a short in the wiring, and am going to give this a shot. Let me know if any of you think this is a good idea or a bad one.
  • Hope you can help, I own the same vehicle and I am currently having the same problems. I have also replaced two alternators and the battery. Someone advised me to change the electrical voltage regulator and that would take care of the problem. Just wondering if you had found out anything about your situation or to see if maybe my advise may help you. Please contact me with a solution to the problem if you found one. e-mail address Thanks, Crystal
  • My problem was, the temperature gauge was fluctuating between cold and hot (needle going all the way up to the red area). After checking all the obvious signs of overheating; bubbling or overflowing water bottle, bulging hoses, etc. I realized it was just a bad temperature gauge. It still fluctuates all the way up to the red (hot) area... I have not been paying it any mind. It is not overheating. We have been driving it like that with no problem. And no, I have not yet put in a different temperature gauge. At some point we will put in an after-market MECHANICAL temperature gauge, as opposed to an electrical or electronic one.

    2 years ago, I DID replace the Alternator when it went bad.... by chance I found an unused alternator on eBAY for $30 and I paid a "sidewalk mechanic" $100 to install it right in my driveway - in mid winter no less. For comparison, this would cost approx. $500 at the dealer.
  • My 2000 Mercury Cougar has been stalling (especially in the morning after a few kms) and car dealership or garage do not know why. It usually happens in the morning and weather does not seem to influence the pattern. It has also happened in the afternoon when I was turning from the highway (80 km) to a side road. I was able to get on the side road but had no more power steering. Just before it stalls, I can hear a very loud sound and the rpm goes down (it is around 1.5 and the needle goes down). It stalls especially when I am at a red light or stop. This problem is intermittent and never seems to happen when the car is in the garage. Does anyone have an answer?
  • Greetings everyone, lmoreno3 here. Just a couple of questions. My sons '00 Cougar with a V6, was showing that it was overheating, after a lot of work done to it, I removed the thermostat, after having it changed three or four times. Cold season is coming up, and I asked him if he wanted me to install a new thermostat, he said what for, the car heater and defroster are working fine. He turned the car on and let it get to operating temp., turned on the heater and the defroster, and warm air was coming out, when he turned up the heat, it came out hot and the car did not overheat. Question, does anyone know how many thermostats this car has? I was under the opinion that it only had one? If it has more than one, where is the other one located?

    Thanx in advance for the help.
  • Your sons cougar probably has a bad temperature gauge; the thermostat is probably fine. I belive there is only 1 thermostat.

    When the Cougar is running hot, give it a good bash on the top of the dashboard right over the Temp. Gauge, it's tricky cause the Dash is curved, but you'll notice that if you bash it good a couple times, the needle might jump right to the correct spot.
  • So i have been eyeing up a 2000 cougar. its the v6 and has a lil over 100k on it. i have been doing a lil reserch on them and they all seem to have some of the same issues. none seem to be too crazy but some do. i realize that i am buying a higher milage car but i think i will be purchasing a ext. warrenty for it. i would like some feed back from cougar owners on how they like the car esp. post 100k owners. thank you verry much
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