I have a 2000 explorer XLT that makes a pinging sound from the motor. It has a 4.0 OHV motor in it. I took it to the dealer a while back and they said it was carbon build up on the pistons. Does any one know any thing about this or have the same problem. It runs great but it only pings while idling and seems worse when its cold. I really would like to make it stop. Thanks for replying in advance.

 

There have been lots of posts on this. There are several possible causes. Carbon is one. More likely is a dirty MAF sensor. You need to remove the sensor and VERY CAREFULLY clean the two filaments. I used a toothbrush and carb cleaner. The screwsx that hold the sensor down are security screws and you will need a special torx security bet to get them out. You might be able to find them at Pep Boys. I had better luck at a mom and pop hardware store. Another possible cause of pinging is the lower intake manifold bolts become lose creating a vacum leak. Torque them suckers down! Also check the vacum hoses for cracks and leaks.

Good luck!

 

Not sure if this works but Try this:

Go out on an open road and floor the accelerator from a dead stop. Try different ways too, like when going 25mph, floor it up to 70.

Not sure if this works or not but there was a service guy at the ford dealer (was crazy)...when i used to bring my cars in for service or other jobs he would always say "Hey mark, im gonna run the carbon out of your engine!". I said "OK!". lol, but anyway, i think this might flush some out.

i think i had a little too much to drink tonight.

 

Mustangsvt,

It's somtimes referred to as an Italian tuneup. You run the snot out of it hoping to burn off some of the carbon. I'm not sure it works but it's a good excuse to drive like a maniac.

Mason

 

Lol, figures, i am italian.

 

Never heard of pinging only while idling. Are you sure it's not a noisy bearing or belt or?????

 

Thanks for the advice. Its been making this noise for a while. I had it looked at by a dealer a long time ago and they told me it was carbon knock so i drove it for awhile but its starting to get on my nerves. I m new to this web site and was hoping someone had a suggestion on getting rid of the noise. I will try these suggestions and hope it will fix it

 

There's a TSB about decarboning the engine...I'll see if I can find it when the search function comes back.

 

found it. The text of the TSB is in this thread....

https://www.ford-trucks.com/forums/s...2B%25252Bknock

 

I had a pinging problem on my 1994 explorer. I had it checked out and he said it could possibly be the flywheel. He said the flywheel would make it ping at idle

 

Im going to try getting the carbon out this weekend. Thanks for all the advice.

 

I implemented the carbon removal TSB on my 94 Ranger 4.0 and it does work. Use PM3 carb cleaner available from your Ford parts department and make sure to replace the spark plugs when done (it will run lousy if you don't). Clean the MAF sensor too; some carb cleaner and an artist paint brush work well. Be nice to that MAF sensor; it's delicate. BTW, put some cardboard under the tailpipe when decarboning to save the driveway; the crud is gonna flow.

 

Wouldn't be a bad idea to change the oil too.