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Mercury Cougar Engine Questions



  • vtraudtvtraudt Posts: 52
    Should be on the front side of the overflow bottle. It sits a bit low. The connector is one of those where you need to push in the metal/wire clamp to pull it off.
  • avp0713avp0713 Posts: 8
    I thought it was on the drivers side of the engine, connected to the Block, near the thermostat hose. That's where mine was, and I replaced it. Perhaps i'm talking about a different sensor? It was a large brass screw-in sensor with a harness wire connected to it.
  • maejinmaejin Posts: 11
    thx for the posting but my overflow bottle does not have a sensor
  • maejinmaejin Posts: 11
    thx for posting...I will let my mechanic look in that area.
  • decrottydecrotty Posts: 15
    The coolant bottle is on the passenger side just behind the fill tube for the window washer. In between these two about six inches down are some wires, one of them connects to the coolant sensor.
  • maejinmaejin Posts: 11
    Thx for posting, However, the overflow bottle was taken completely out...inspected and cleaned...there is NO sensor
  • 2002 2.5L v6 Cougar died while driving. Engine cranks but will not fire. After 30 seconds of cranking battery dies. Recharged battery and within 30 seconds battery dies. Replaced crank sensor and ignition coil, tested battery OK. Engine still will not fire.
  • 99 cougar runs good and quiet all summer and now with the first chilly frost, it squeals turning out of the garage and that usually precedes the no start problem. Had it towed to the dealer , couldn't find fault. Drove it home ok. Seems like a lot of moisture coming out of exhaust all yr long.
  • Check the fuel pump. There was a recall of fuel pumps about that time and my 2001 V6 Cougar died on me on the road for just that reason.
    As for the battery, i'd say it needs replacement.
  • If your first cold day is in late December you must live far south of me here in Northern Ky. The squeal as you turn out of the garage has to be the belt to the steering pump.
    The moisture in the exhaust could be a leaking head gasket. Take out all the spark plugs and see if one of them is wet or if water comes out of one of them as someone else cranks the engine. Look closely at the oil fill cap for white foamy moisture, another indication of a gasket leak.
  • Do you have white smoke coming out of the exhaust (not just when engine is cold)? But head gasket and belt is hard to imagine they are 'connected'.
    Get the squealing out of the picture first (start with 'belt spray') to see if it really preceeds the no start.

    Find the wet plug. Car should be running rough; doesn't have to be all the time, since the plug may be initially dry, but gets 'blown out' by the water leak.
  • This car (150,000miles) had a stumble on acceleration last summer and the code set was for the EGR valve. Finally fixed it by replacing the Differential Pressure Feedback EGR sensor (and the EGR value too). Worked fine for 6 months. After filling up on gas one day it started to stumble on acceleration again. Adding dry gas additives made no difference. This time no codes have been set even though I purposely try to get it to stumble sometimes. I've been through 3 or so tanks of gas since then. The plugs look good and were replaced last summer as one attempt to fix it the. I've replaced the fuel filter, even got another of the DPF's. Any suggestions? Thanks.
  • I recently purchased this vehicle and have been working on the interior. Has 83,000 miles on it with original 390CI. Just rebuilt the engine and has less than 50 miles on fresh rebuild. Live in Michigan and looking for advice on starting it all winter long with temps averaging in the 20's. Should I start it and run for 20 minutes or better off not starting until spring?

  • Personally I wouldnt' take a vintage out on the road in a Michigan winter. In any case, even 1969 cars warmed up in a minute or two and the choke was fully capable of getting it running immediately. Even if this is the first start after the rebuild there should be no harm starting it.
  • Thanks for the quick response. The vehicle would remain in the Pole Barn and I have started and ran it for about 20 minutes. It does start right up and comes to correct temperature. Had an individual state not to run at all until spring due to moisture build up. That is what is concerning. Have 8" of snow now and expecting 5-6" overnight. No roads for this vehicle until late spring.
  • I've always wondered how to keep a car dry. Unless you build a tent around it with a dehumidifier inside your best might be to leave it open with a light cover to keep the dirt off. There might be a discussion about this in the collector magazines somewhere.
  • Thank you for your response. Have it covered and very much looking forward to spring
  • i have a 2000 mercury cougar that i just replaced the fuel pump on. it runs great and idles awesome but after it warms up(can happen after 3miles up to 50miles of driving)if i try to go up hill or stomp down for passing gear it stumbles and bucks, spits and sputters. the car takes fuel fine if given at a normal slow and steady pace and it returns to normal as soon as i leave off of the gas when under a load. it is a v6-2.5 we have checked maf, it does code egr but i dont think that the egr does this. changed filters and out of ideas. any help?
  • I understand that the default air vent is the defrost vent when you can't get the push buttons to move the air to the floor or the front vents. There are no air leaks that can be heard. From the engine compartment their are 3 vaccuum lines going into the car thru the fire wall. Now where are they going? I see the small cluster of colored vaccuum lines pluged into the back of air vent control panel, but no sign of the black vaccuum lines. Two of the three vaccuum lines are 5/32", and the other one is 1/4" in diameter. Does anybody no where I can find a picture of the vaccuum lines are going under the dash????
  • loisyangelloisyangel Posts: 3
    I have a 2002 cougar and my son in law was driving it when he going up hill it lost power and the engine died. A friend of his (backyard machanic) took a look at it and claims the timing belt went on it. Then a different machanic said the timing belt was fine. How can I know if it is the timing belt. the car won't even start up. I also heard if it was a certain type of motor the engine us now useless. Do you know what this type is? I also was told I should have had the timing belt changed at 60,000m it is now at 63,251. Is this true?
    Thank you, Lois
  • aussieechoaussieecho Posts: 22
    to see if the belt is missing ,take off the plastic engine cover, remove the metal oil cover . While someone is trying to start the engine look to see if the valves go up and down . If they go up and down the belt is still intact.

    the factory recommends changing belt about 60 000 ,but its expensive and usually not that critical under normal driving.

    the speed at which the engine was going at the time of the problem will be of some consequence as to the damage .
  • vtraudtvtraudt Posts: 52
    On the Cougar engines I worked, there was a timing chain, not a timing belt (Audi's for example have timing belts). Timing belts need to be changed frequently (80k miles), and just as important the time belt tensioner. I have not heard a similar recommendation for timing chains.

    When the timing chain or belt breaks, the resulting damage on a 'interference engine' (where valves and piston can touch each other if out of sync) can be catastophic. From nothing (lucky, happened at low rpm and no load) to bent valves (new heads or remanufacturing of heads, new valves, guides, seals, etc.) to basically new motor form damaged pistons.

    If your engine has timing belts fails, first try to turn the engine by hand to feel if there is any interferenc; then see if cam shafts rotate or valves move (if one side moves, the other must move too and you belt is on).

    Note: not talking about the serpentine or accessory drive belt. If that fails, nothing really happens, except battery not charged, power steering not working, AC not working, engine may overheat and similar.
  • loisyangelloisyangel Posts: 3
    thank you for responding so quickly. as it stands right now it does not appear to be the timing chain, he said something about the cam shaft. but still not sure what the problem is. i looked up my engine and found that it is not a "interference engine" which i'm gathering is a good thing.
  • loisyangelloisyangel Posts: 3
    as it turns out it appears that the timing belt is not the problem it is still there and tight. he said something about the cam shaft i didn't understand what he was saying. i also check out some info on the enging and it is not a "interference ?" which i'm in the understanding that is a good thing. thank you for responding so quickly. i had the guy do what you said about checking thet belt. thanks lois
  • decrottydecrotty Posts: 15
    The check engine light should be on. If so get a small code reader from auto zone and start with that what its says.
    No codes? Hmmmm. The V6 has a timing chain which never needs replacing likethe belts on some. However, just to be sure, take off the oil fill cap and crank the engine. You should see a bit of the cam moving. Also if it cranks smoothly and the cam moves you probably don' have that type of problem.

    Could be a lot of things. That era had a recall on the fuel pump and what you describe happened to me. The car just died. It cost $700. However the next year the recall come up and they repaid me even the towing.
  • There is a sensor directly under the thermostat housing. If the clip breaks and the thermo housing slides the plug out the slightest bit, the car WILL NOT turn over. Reach down, pull the thermostat housing up, and push the plug as far back as you can. If it does no snap into place you can remove the battery and the air box from the throttle body and get a long zip tie around it and sinch the plug back into place. Hope this helps. This plug backing out a hair had me puzzled for days!
  • It is a breather tube for the transmission dipstick. It is supposed to mount with a clip on the battery tie down bolt closest to the fire wall. It goes where ever its not in the way or hanging downward.
  • redcat99_redcat99_ Posts: 4
    My car misfires and sputters only when the car is cold and only when you're stepping lightly on the gas pedal, works fine on open throttle (runs fine when running at temperature). What could be the problem? Check engine light never comes on. I've changed spark plugs, wires, and fuel filter, cleaned the intake, oil & filter changed frequently. The car has had the stock air filter taken out & a short air intake installed (but ran fine with it). Also, when you take off the short air intake pipe at the intake (pipe has the MAF sensor in the piping), it works exactly the same... would have thought that it wouldn't run right without the air running through the MAF sensor...
  • PF_FlyerPF_Flyer Pennsylvania Furnace, PAPosts: 7,717
    I'm not an expert mechanic, but it seems like an issue with the throttle (I know... DUH)

    When you say "stepping lightly on the gas" do you mean when you start out normal driving? Or is this something that you just happened to notice happening with the car sitting still just after starting?

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  • redcat99_redcat99_ Posts: 4
    Yes, it's during normal driving, when you are starting to accelerate (happens also if the car is in neutral and you press on the gas a little, so I know it's not a transmission problem). It has this problem only when the car hasn't reached running temperature. The car runs fine otherwise.
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