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Mercury Cougar Engine Questions



  • E-bay our buy it at the dealers.
  • jjb009jjb009 Posts: 1
    I have a 2000 Mercury Cougar and about 2 months ago the check engine light came on – the OBD-II code was P0128 - Coolant Thermostat (Coolant Temperature below Thermostat Regulating Temperature). All seems to be well with the car.

    I live in WI so it is very cold now (Jan/09) and overheating should not be an issue; the car is producing heat in a timely fashion and it isn’t running hot. I disconnected the battery to see if I could get it to kick out the trouble code again. The check engine light went away – but came back about 2 weeks later; I ran through all of the same steps and got the light to go off again.

    On my way to work this morning as I switched the heat from defrost to deforest/floor and the check engine light came on again and as it came on I remembered that this was the same thing that I was doing (switching the heat) when the light came on a few weeks ago.

    Could there possibly be any connection between the heater and the check engine light?
  • im sure u already have this answer, but it doesnt go anywhere, its a vent.
  • vtraudtvtraudt Posts: 52
    I learned back then from the posts that this is going no where, just an open vent hose.
  • The check engine light is it the one on the dash our the one in the head liner?
    If it is the one in the head liner ( the shape of a wrench) it is telling you that it is time for an oil change, there is a spot in owners manual to reset it. If it is the one on the left side of dash is the you need to pull the heater controls out and clean them and see if that takes care of it
  • HELP!!! My baby, an 86 Cougar, has developed a problem and you don't know when it will occur; but seems to happen after getting warmed up. For instance, drove to work, everything fine; on way home stopped by store. Waiting @ red light, engine idle fine...light turns green & I press the gas and she bogs & dies. Started back up OK, but then had to keep foot on brake & gas when slowing or stopping or car would die. I'm not ready to give up on the old girl---she's been too good to me for over 20 yrs. Up until now, she ran when all the others would break down!!

    86 Cougar
  • Where is outside sensor located on my newer Mercury Cougar that registers the outside air temperature on the inside of my car? Ive always wondered where this is located on a car.
  • My son car will shut off when driving down the road it will do it only sometimes and he can only get heat or air through the defrost vent will not come out the vents in dash. If anyone can help I would be very thankful he is very upset it's his first car thanks for any help :cry
  • vtraudtvtraudt Posts: 52
    We had the same problems:
    - shutoff when driving: it starts with the lights going dimmer, then the instruments go all wacky, then the engine cuts out. Daily recharging of the battery helped to get by for 1 or 2 days. At the end, we changed the alternator, which fixed it in our case
    - no heat/air coming from vents (except defrost): this was going on for more than a year. This week we had to take the engine apart (white smoke, fouled up spark plug: looked like head gasket. It is now back together; we'll see). In the process, we found a small plasctic vaccuum line broken. I patched it up by using a small (just to fit over the plastic line) and a larger (that fits over the first) shrink tube to connect the 2 broken lines. If/when the engine is running again, we will report if that solved the problem (VERY likely).
    Let me know if you need pics to identify the tube which caused the problem in our case (could be any vaccum line though; vents are moved by actuators powered by the engine vaccuum; if you have a leak, the vent stays in its default position, which is "all air to the defrost").

  • We found a line vaccum line off but do not know were it belongs and the diagram under the hood does not help and the book only shows the line for a supercharger and we have a 3.8L with out charger my son never said the dash went crazy it just shut off the started thanks for the help I will keep tring to get it.
  • 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: 5,854
    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.

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