Mercury Cougar Engine Questions



  • vtraudtvtraudt Member Posts: 52
    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.
  • decrottydecrotty Member Posts: 15
    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.
  • timeservedtimeserved Member Posts: 3
    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?

  • decrottydecrotty Member Posts: 15
    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.
  • timeservedtimeserved Member Posts: 3
    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.
  • decrottydecrotty Member Posts: 15
    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.
  • timeservedtimeserved Member Posts: 3
    Thank you for your response. Have it covered and very much looking forward to spring
  • saunt7902saunt7902 Member Posts: 1
    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?
  • metalman56metalman56 Member Posts: 1
    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 Member 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 Member 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 Member 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 Member 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 Member 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 Member 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.
  • fordfinatic93fordfinatic93 Member Posts: 2
    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!
  • fordfinatic93fordfinatic93 Member Posts: 2
    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_ Member 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, PAMember Posts: 9,400
    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?
  • redcat99_redcat99_ Member 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.
  • PF_FlyerPF_Flyer Pennsylvania Furnace, PAMember Posts: 9,400
    With a little digging (I always try to learn something every day) I'm thinking it may be a problem with your engine coolant sensor since so many aspects of the engine management systems like fuel, ignition, and emissions are affected by engine temperature.

    This makes sense to me and is where I'd check first (or have my mechanic check). If the sensor is malfunctioning and "thinks" that the engine is already at operating temperature, then the computers that now run our cars think that everything is ready to go as if the engine is warmed up, but since it's not, the computer trying to run the engine is using the wrong "settings".

    Sound reasonable?
  • decrottydecrotty Member Posts: 15
    No codes, no check engine light. You're the one who changed the gas filter, plugs wires. Three things I had trouble with:
    1. take off the air intake. Just inside there may be carbon clogging a couple of little holes.
    2. There's differential pressure sensor that goes bad. Two types. One metal located just under the air intake, or it could be plastic just around to the back of the engine.
    3. Take off the ignition coil block. Look at all the connectors. All should be shinny. If one is carbon dull, that one is missfiring. Replace the ignition coil.
  • redcat99_redcat99_ Member Posts: 4
    That's something to definitely look into pf_flyer. Thank you!
  • redcat99_redcat99_ Member Posts: 4
    Thanks decrotty, I will definitely look into this too!
  • vtraudtvtraudt Member Posts: 52
    Car dies while driving.
    Jump start keeps it running until battery is drained.
    Back of alternator has pos battery voltage, and continuity (so 'mega fuse' is good).

    Is there another fuse in the charging circuit that could be blown?

    Other checks that can be done before alternator has to come out for testing?
  • aussieechoaussieecho Member Posts: 22
    while the engine is running stroke the wires coming out of the air box to see if that settles things down. If so clean them. Those wires are part of the air temp sensor, this helped stop a squeeling we had when cold
  • jmays2jmays2 Member Posts: 2
    I have a 2000 Cougar with the 2.5 V6 that needs replaced. It has an automatic transmission.
    Can I replace the engine with a 1999 2.5 that has a standard transmission?? ( i don't want to swap the standard trans because it is broken)
    I am new to cougars so any info would be greatly appreciated.
  • jvoelkejvoelke Member Posts: 2
    I have a 2000 Mercury cougar V6 2.5, Upon starting the car and backing out I give the car gas and it putters a little then gets up to speed, when it hits about 20 it bucks a couple times, If hold on to the gas it gets worse if I take my foot off and replace it it seems to get better, but it takes forever to get up to speed. When it finally hits about 40 it does the same thing, about every 20MPH.. when steady on interstate it is fine, unless I give it gas to go about 5 more MPH it bucks again. The code at autozone read misfire on 4 and 6.. Ive read all over and people are saying it's either just a tune up, or the neutral saftey switch.. I can't make up my mind on which it is and I don't want to do both right now, So im asking if anyone knew which one it is for sure? Thanks
  • jvoelkejvoelke Member Posts: 2
  • usmustrustusmustrust Member Posts: 2
    edited August 2011
    Hey man I have the same car. I can probably help you with any problems you are having.

    I just swapped the engine myself a few weeks ago and got some misfire problems also.

    If you do the following you'll definitely eliminate the problem you are having right now.

    Fuel Injectors (remove your fuel rail and inspect the injectors for leaks)
    remove each injector from the rail, clean it and the rail itself, scramble the order of the injectors and re install them each into the rail)
    Fuel Injector connectors remove the connectors formt the injectors, clean them with no residue electronics cleaner and reinstall...use dielectric grease on the contact when u reinstall.

    Spark Plugs
    Get NGK TRG55K sparkplugs - they are the platinum ones
    install them and put dielectric grease on the wire connector, sparkplug ceramic and the connector that the wire goes on

    Upper Intake Manifold Gasket take it off, clean it with rubbing alcohol, get hi temp silicone from your local parts shop and put it on the gasket then reseat the gasket to the Upper intake Manifold...

    Throttle Body Cleaner

    follow the instructions on the bottle. When I had my Upper Intake off the car, i just sprayed carb cleaner inside of it ,,,,scrubbed it best i could and sprayed the heck out of the throttle body opening with the cleaner

    After doing these if you still get a misfire change your coil pack you can get a new one from or goto a local auto wrecking yard and pull one from another cougar.

    reinstall everything back together....these few tasks should take anyone with basic mechanical know how about 3 hours or less to complete and I pretty much guarantee your problem will disappear. Good luck feel free to write me with any questions etc.
  • cougar20cougar20 Member Posts: 1
    change the fuel rail pressure sensor. also take it into the shop and they have a code sensor that tells you what is wrong with it. i have the same car did the same thing changed it and it does not do that anymore all i have to do now is get another sensor because of something else and i am all done. dont listen to the guy below that is way to much work. any further questions just ask.
    you can get the part at any ford dealer.
  • oil_monkey1oil_monkey1 Member Posts: 13
    I have had my Cougar for about 4 yrs. Just before we bought it the previous owner replaced the alternator. about 1 1/2 yrs later the alternator went out and I took it to a starter/alternator place and had it rebuilt which lasted about a yr. Took it to a different starter/alternator place and the car ran great except the battery light would flicker at about 5500 RPM+ but the mechanic couldn't find any problems. It lasted about 1 1/2 yrs and went out again. Took it back to last starter/alternator mechanic (who only charged me labor) to fix it. Still not fixed since the light starts to flicker at various RMP' s now. Any suggestions??? I have about had it with this ongoing problem... thanks
  • costelmaccostelmac Member Posts: 1
    Did u fix your problem? I have exact same situation and dont know is it the PCM or the factory alarm or what else could be. Let me know please. Thank you
  • alicia903alicia903 Member Posts: 1
    I have a 200o Mercury Cougar special edition and I am having so many problems. The first problem is that the gas gauge sometimes work but the majority of the time it doesn't can anybody tell me what's going on with that. Then the second problem is that the car jerks a lot when your going over 5o. Lastly today of all days the car just shut off without any notice and will not start at all. Tried cranking it several times but nothing happened. All the lights come on so there is nothing wrong with the battery can somebody answer any of these questions I would be grateful. Thanks in advance.
  • aussieechoaussieecho Member Posts: 22
    sounds like fuel starvation, disconnect the fuel line off back of engine where it connects to the fuel rail. Put glass jar under coming line and crank engine. Fuel should gush out of line from fuel tank. If not, fuel pump filter or pump might be problem
  • decrottydecrotty Member Posts: 15
    The fuel pump on that year was replaced on warranty. That's exactly what happened to me when the car was about 2 yrs old.
    As for the fuel gauge, the fuel tank has to be removed to get at it. While doing that check the wiring to the tank.
    That being said, similar things happened to me much more recently and it turned out to be the ignition coil.
    An error code has probably been set. Go to Auto Zone and ask them to read the code. They might be able to point you in the right direction.
  • vtraudtvtraudt Member Posts: 52
    i removed the fuel pump/gauge from the top. Under the rear bench is the access door. Lid likely very difficult to remove (I had to use hammer/chisels to turn the lid).

    not a bad idea to have a spare lid and o ring/seal on hand (from same guy/junkyard you get the new pump assembly?).

    I could not fit the hole assembly through the hole in the sheetmetal, so I did a few surgical cuts with the sheetmetal snippers and later bent those down again (and sealed with epoxy).
  • prostreet49335prostreet49335 Member Posts: 1
    is it hard to put in a new motor in my 1999 do i do it. thanks! :confuse:
  • markponce88markponce88 Member Posts: 1
    hi im also having the same problem with my sisters 99' mercury. i wanted to know if u ever found the solution to that lose hose? if u could pls reply back that would be appreciated.
  • missrutmissrut Member Posts: 2
    Did you ever figure out your problem? I am having a similar problem. My car when started the other day ran rough. I turned it off and it would not start again. changed the fuel pump and it ran great for 4 days until I filled it up with gas. now it is doing the same thing and we tested the old fuel pump last night and it works fine. so it was not the fuel pump to begin with. And we have no idea what it could be.
  • ratscats23ratscats23 Member Posts: 3
    edited May 2012
    I just had major work done on my car cylinder head replaced,waterpump,starter,thermostate,egr feedback sensor get all of it back together and this little plastic elbow shaped breather i think comes tumbling out from under car.We have no idea where this part came from.Im gonna try to upload some pictures can ">someone please help<img src="C:\Users\jenny\Documents\Desktop\attachments\IMG_20120518_021106.jpg
  • ratscats23ratscats23 Member Posts: 3
    edited May 2012
    please can someone tell where this part goes just post the above url in your browser and the picture will pop up
  • ratscats23ratscats23 Member Posts: 3
  • vtraudt1vtraudt1 Member Posts: 3
    Your photo link does not work (at least for me).
    Try again. Not sure how it works here, but there is a "IMG" button in the bottom. Or upload photos to photobucket or similar free web hosting side then post the link to it here.

    I have a ton of Cougar stuff that goes to the junkyard very soon.

    you can also email me to

  • algiddalgidd Member Posts: 1
    Hey folks any help would be great. I have an 02 cougar C2 edition v6 I am replacing the fuel pump for the 4th time in a year. Any ideas what could be causing it.
  • cougarsurvivorcougarsurvivor Member Posts: 1
    If you haven't already done it, I would:
    1. Switch to a different gas station.
    2. Switch to a different parts store.
    3. Switch mechanic tech.
    4. Pour a bottle of Seafoam into your gas tank with EVERY OTHER gas fillup.

    Outside of those items, perhaps there is some type of electrical issue? The Fuel pump is such an item that it is somewhat rare to need replacement so often.

    Hope this helps.
  • decrottydecrotty Member Posts: 15
    That fuel pump was a subject to recall back then. You may be buying the defective pumps from resellers. Go to a Mercury dealer for the new pump. If that car hasn't had the recall you might get it free. Otherwise you will be sure to get the better pump. It might be a bit more expensive but it will work.
  • jerry7234jerry7234 Member Posts: 1
    my son owns a 1999 cougar and I get a p1518 how do I fix this it is a intake manifold runner stuck open
  • davvvesdavvves Member Posts: 1
    My 1995 Cougar wont pass the smog test. The check engine light is on, but it passed every part of the test except the air injection. So the emissions passed but the functional check failed. Anyone have experience fixing this?
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    You might find THIS VIDEO helpful
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