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Help! Engine rich and overheating intermittently!

Discussion in 'Stock 2002 - 2005 Explorers' started by superdad123123, May 16, 2019.

^^Searches ExplorerForum.com^^
  1. superdad123123

    superdad123123 New Member

    Joined:
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    City, State:
    wilmington, nc
    Year, Model & Trim Level:
    2002, explorer xlt
    This is my only vehicle which I bought in january after someone totaled our sequoia, got 3 kids and need this thing running right.

    Okay so I have a long story with my 02 explorer and i feel like i get close to a solution and something else happens.

    2002 Explorer 4dr 4x4 4.6L
    152000 miles
    engine replaced before I bought unknown mileage.
    Bought this in january.

    replaced all the plugs, coil packs,serp belt, egr valve,egr tube(broke the old taking off the rusted egr), egr backpressure sensor, 02 sensors, oil pressure switch, thermostat, pcv valve, air filter and the oil was changed yesterday may 14, 2019.

    smoke test was done and came back with no vacuum leaks.

    main issue-

    check engine light comes on and started flashing, shooting p301 misfire cylinder 1 and rich bank 1 intermitantly. codes would come on and go off until the plug in cylinder 1 stopped firing all together and needed replacing, I cycling through this 3 times, cylinder 1 is on its 4th plug. no other cylinders have coded as misfiring. There is a loud tick that comes and goes in the front in somewhere around the passenger valve cover or bank 1.

    I replaced the upstream bank 1 02 sensor and immediately got a rich code and a idle at 2000 rpm in park and 1500 in drive,same day engine overheated(however I recharged the ac same day and it is the third time it has overheated when I recharged it), figured out I put a downstream sensor in the upstream so I swapped it to the back(opposite side to verify it wasn't the sensor) and installed the other 3 new sensors. Upon start after hard resetting the computer(disconnected the battery) the engine ran very smooth, the click click click smoothed out and all seemed good. Then after it got warm the engine got a little rougher and shot a rich code bank 1 again and the clicking returned.

    I took it to get an oil change as the oil had turned black from all the misfiring, I had them replace the oil pressure switch because my gauge has been going from normal to low(lighting up 'check gauge'), also had them replace a quart with lucas high mileage oil stabilizer. after the oil change the engine has been much much quieter with the tick only coming back once so far but shortly went away after heating up. no overheating and have driven about 30 miles since the oil change. Still have the rich codes, but it is idling normal at about 700 750 and not shaking barely at all, just a normal shimmy for a 17 year old vehicle. Also has been holding coolant this time(when overheated the last two times the water boiled out of the reservoir-possibly cracked my radiator)
     
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  3. IPcamper

    IPcamper Elite Explorer

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    Year, Model & Trim Level:
    2002 Mercury Mountaineer
    I am no expert, but I have had two of these vehicles with the 4.6l engine. The ticking sound could be the timing chains slapping around. The guides are plastic and a common failure point. The quickest way to check them is to remove the valve covers. You can look down the chains and look at the guides, also you can see if the chains are loose. Some people have had problems of reduce oil flow when bits of the plastic guides block the oil pick up. This can quickly ruin the engine.

    Replacing the timing chain guides is a full day job for me, I did it on both my old explorer and my current Mountaineer. Removing the oil pan to get to the oil inlet can be done, but you will need to remove the three bolts holding the front differential to the frame and lowering it a bit to get clearance to remove the oil pan.

    As for the rich condition of bank one, since you ruled out an air leak with a smoke test, you might check for a bad fuel injector.

    If you find this is the problem, you can find a lot of write-ups on timing chains by searching this forum, and by searching for youtube videos.
     
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  4. superdad123123

    superdad123123 New Member

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    City, State:
    wilmington, nc
    Year, Model & Trim Level:
    2002, explorer xlt




    I just changed out the injector for cylinder 1 was only able to drive it for around 25 miles tonight to test, but I got no more check engine light after resetting the battery, so hopefully that means it worked.


    So on this timing guide issue,

    I do a a fluctuating oil pressure gauge and have had one since I got the car, never really changed how it was running when it intermittently drops to low. It just pops up and says check gauge and then if I give it gas it will pop right back to normal.

    Other than that I haven’t really had any oil pressure issues.

    With a fresh oil change the engine runs smooth as ice then a couple days later the ticking will come back intermittently.
     
  5. Joe in NY

    Joe in NY Active Member

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    City, State:
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    Year, Model & Trim Level:
    2002 Eddie Bauer V8 4X4
    Sad to report if the gauge id dipping to L that means 0 PSI. Not good. Ford only used a 5 PSI (ish) switch for the idiot gauge. Funny though that the Ford diagnostic manual states a minimum of 10~15PSI at idle to be acceptable...
     






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