'94 Pinging and Rattling

[jrk4]

I have a 94 Exp with 107K miles...it has been a great vehicle...no major problems what-so-ever. Lately I've been getting a lot of pinging from the engine when I accelerate. The harder the accel, the more pinging I get. I also notice that when the engine is at idle, it chugs a little....like it can't "breathe". Nothing major but certainly not the norm.

I am clearly not very auto-repair savvy, but I know enough to find my way under the hood. Can anyone give me some pointers as to what may be happening?

I appreciate any suggestions that you may have to offer!!
JRK4

[mfayant]

either you're low on oil or your engine is about to go on the fritz. Sounds like lifter problems.

m f

[molehole]

First Gen Explorers are known for pinging. Mine does it a lot but then doesn't do it for a while. Try running a tank of premium fuel through it. Also clean the throttle body with some good throttle body cleaner. Also when was the last time it was tuned up or the fuel filter changed? Could be any number of things.
Here is some info from a ford explorer website. Hope it helps Good Luck!

Fix for a Missing Engine

Many Explorer owners have experienced "bogging" or "missing" or just unsteady performance in their 4.0 engine and have been frustrated by lots of expensive "non-fixes".

It seems that a "missing" engine culprit is actually the computer's sensor inside the Mass Air Flow Sensor (MAF). It eventually just gets a little dirty or builds up its own patina in the filament wires. A dirty or slightly patinated filament will send the wrong air reading to the computer, saying it is getting more air than it really is and the computer will tell the EFI to send in the wrong mix of fuel, thus, the bogging. The patina seems to form faster if you live in a damp climate. it would run just fine but the idle began to drop every few revs from 700 to 500. No big deal.

If you have had bogging or missing or idle spots, about every 25K miles plan on this quick cleaning job:
When your engine is cool, remove the wiring clip from the side of the black plastic sensor part of the MAF aluminum body. To remove the MAF interior sensor wire, you will need a Security Star (Size T15 or T20) screwdriver or screwdriver bit for a power screwdriver. Remove the two security star-head screws and carefully remove the sensor. You will see the two sensor filaments…they look almost like the filaments on a light bulb. Carefully spray the filaments with an O2 safe carburetor cleaner, such as Gumout. Let it dry thoroughly. I help mine along with a careful blast or two of canned dry air. While it is drying carefully wipe the aluminum mount surface of the MAF body if there is any dust there, but be careful not to get dust in the mount hole. When the sensor is dry, replace the sensor back in the MAF body and secure with the security star-head screws. These don't need to be torqued down, just simply hand tight. Replace the wiring clip. Then start up your engine. You should have solved any bogging or missing problems. My flat idle spot is ancient history.