Pinging on Hills

[lobo411]

Hi all,
I think my 1996 4.0 Explorer XLT w/ 160k mi has developed a ping. At first I didn't even think it was pinging. It only happens when I'm on a major hill like the Conejo Grade on the 101 (7%), usually about 2/3 of the way up. The sound is like a ticking or fluttering sound, and the first few times it did it I thought there was a leaf in the dash vents or something. Then I listened to someone else's youtube video and it sounded the same:

http://www.youtube.com/watch?v=JA0cH_vRABg

I've got no codes, the engine runs great otherwise (20 MPG), and it only does this on a severe grade. I changed the plugs/wires just as a matter of routine last summer and they looked perfectly fine (it pinged before and after the plug change). The car has been burning oil for the last year, though. I never used to have to add oil between changes, but I probably drove it around 1500 miles a year. Lately I've been commuting 300 miles r/t one day a week, and every week I have to add 1/4 qt of oil.

I'm thinking I'll try some Lucas injector cleaner in the tank, and I'll put it in on my way home from my commute. That will run a full bottle of cleaner through a half tank on a hard/hot run, and my tank will be almost empty when I get home. Is that a good idea? I could put it in at the start of my commute instead, on a full tank. Thanks!

 

[koda2000]

"pinging" is caused by pre-ignition. this happens when fuel is ignited by compression before the spark plug fires. it's also know as "dieseling" as that's how a diesel engine works. pre-ignition can be very damaging. as engines age they tend to build up carbon deposits in the combustion chambers. these deposits cause hot-spots and can actually raise compression, both of which cause pre-ignition. try using a higher grade of fuel and see if it stops.

 

[colintrax]

Higher octane will probably stop the pinging but not fix the problem. Try running seafoam through the intake and seafoam or techron in the fuel.

 

[lobo411]

Thanks for the tips! I've got a bottle of Lucas that my dad bought and has been sitting in the garage for a couple of years now, so I'd like to use that up first and then run some Techron for good measure. Is it a good idea to concentrate it by running it though a 1/2 tank, or should I stick with a full tank?

I'm still not even 100% sure it's pinging, to be honest. I googled and people describe it as sounding like BBs in a spray paint can, and my sound isn't metallic at all when I hear it from inside the passenger compartment. It sounds fluttery, like tissue paper caught in a fan, or like an exhaust leak (kind of like ... pshh pshh pshh pshh). I actually changed the exhaust manifold gaskets at first because I thought it was an exhaust leak but it didn't stop the sound.

Now that I think of it, there are a lot of videos on youtube put up by people who are probably as clueless as I am as to what their sound really is!

 

[colintrax]

Hard to say, really have to hear it in person. However running seafoam through the intake and some fuel injector cleaner is a good idea regardless.
I wouldn't trust the lucas to do anything. As to concentrating it. I have no idea, and you probably won't get a good answer from anyone on this forum. Just guesses.
But IMHO it shouldn't matter. You got a 21 gallon tank (assuming you have a 4 door?), as long as the fuel treatment treats 21 gallons or more it shouldn't make a difference.

 

[koda2000]

Thanks for the tips! I've got a bottle of Lucas that my dad bought and has been sitting in the garage for a couple of years now, so I'd like to use that up first and then run some Techron for good measure. Is it a good idea to concentrate it by running it though a 1/2 tank, or should I stick with a full tank?

I'm still not even 100% sure it's pinging, to be honest. I googled and people describe it as sounding like BBs in a spray paint can, and my sound isn't metallic at all when I hear it from inside the passenger compartment. It sounds fluttery, like tissue paper caught in a fan, or like an exhaust leak (kind of like ... pshh pshh pshh pshh). I actually changed the exhaust manifold gaskets at first because I thought it was an exhaust leak but it didn't stop the sound.

Now that I think of it, there are a lot of videos on youtube put up by people who are probably as clueless as I am as to what their sound really is!

"pinging" is definitely a metallic sound usually heard when taxing the engine (like while climbing a hill). what you describe doesn't sound like pinging. you can concentrate the cleaners w/half a tank of gas, but don't mix them together.

 

[koda2000]

Thanks for the tips! I've got a bottle of Lucas that my dad bought and has been sitting in the garage for a couple of years now, so I'd like to use that up first and then run some Techron for good measure. Is it a good idea to concentrate it by running it though a 1/2 tank, or should I stick with a full tank?

I'm still not even 100% sure it's pinging, to be honest. I googled and people describe it as sounding like BBs in a spray paint can, and my sound isn't metallic at all when I hear it from inside the passenger compartment. It sounds fluttery, like tissue paper caught in a fan, or like an exhaust leak (kind of like ... pshh pshh pshh pshh). I actually changed the exhaust manifold gaskets at first because I thought it was an exhaust leak but it didn't stop the sound.

Now that I think of it, there are a lot of videos on youtube put up by people who are probably as clueless as I am as to what their sound really is!

"pinging" is definitely a metallic sound usually heard when taxing the engine (like while climbing a hill). what you describe doesn't sound like pinging. you can concentrate the cleaners w/half a tank of gas, but don't mix them together.

check your PCV valve, hoses and grommet. that may be the source of the noise you're describing.

 

[colintrax]

Koda why can't you mix them? I've mixed HEET and techron before without issues as far as I know

 

[lobo411]

"pinging" is definitely a metallic sound usually heard when taxing the engine (like while climbing a hill). what you describe doesn't sound like pinging. you can concentrate the cleaners w/half a tank of gas, but don't mix them together.

Sounds good, I'll give that a try. Mine sounds like the fluttery sound you hear a few times between 2 mins 50 seconds - 3 min 5 seconds in the guy's video. Except his does it on more or less flat terrain, while mine does it on big grades. I googled it and the two places it does it are really steep: Conejo Grade (7%) and Mt. Baldy Road (9%). That could be why I haven't seen anything in the plugs...I wouldn't even notice it if I wasn't commuting on the 101 regularly these days.

Maybe I heard pinging when I messed up the plug wiring a few months ago? It sounded like someone was hitting the engine with a hammer, but I had the hood up so it was easy to hear.

 

[lobo411]

OK, I decided to stop using the "quick advice" thread I started because that was more specific to the repair, while this thread is more about diagnosis.

Sat/Sun I replaced the lower intake manifold gasket, fuel injector manifold gasket, fuel injector o-rings, and the upper intake manifold gasket. The lower bolts were loose on cylinders 1-3--maybe they only had about 5-8 ft-lbs of torque--and the lower gasket was starting to deteriorate around the coolant passages (but not badly). I probably could have gotten away with just retorquing the bolts.

I also replaced practically new single platinum plugs with double platinum plugs, but I don't know if this helped much. I've been using single plats forever and the pinging is recent.

I think I fixed the ping! I took the car for a test drive on the same steep grade where it was pinging a few weeks ago...no ping! Also, the car definitely has more pep!

Here's a link to photos of the old plugs. I used fuel injector cleaners for about 3 weeks before starting the repair, and I think the ash is Techron fouling.
http://imgur.com/a/nlNpI#0

Here's a picture of the old gasket, showing the area of greatest deterioration. This would be the front of the engine, near cylinder 1. The new Fel-Pro permadry gasket kit I bought was a two piece design rather than the old one piece. The insert said that the old one-piece design was known for causing loosening.

http://imgur.com/puXdX81

 

[fast_dave]

Haven't read anything about you cleaning your MAF sensor - if dirty that can also cause pinging through a bad air/fuel ratio. And if anything, you'll pick up some HP and Throttle Response. $7 or so a can at any automotive store. ;-)

 

[lobo411]

Haven't read anything about you cleaning your MAF sensor - if dirty that can also cause pinging through a bad air/fuel ratio. And if anything, you'll pick up some HP and Throttle Response. $7 or so a can at any automotive store. ;-)

Worth a try! I'm going to see how it performs when I commute in 2 weeks first--300 miles r/t in one day, including a 3 mile stretch w/ 7% grade where it always used to ping. If it pings, then I'll clean the MAF. If it doesn't ping, then I'll know that the lower intake manifold fixed the issue, and still clean the MAF.

 

[fast_dave]

The MAF is always overlooked, while it should be the 1st thing to look at. In short, the MAF sensor reading are what tells your Ex's computer how to set the air to fuel ratio.

If you've never cleaned your before, I guarantee it is dirty, as they are right in the airstream behind the air filter. And if you're running an oiled filter, the MAF gets very dirty.

For fun, spray your MAF over a clean white towel; you'll see the towel turn brown where the used cleaning fluid drops on it.

While you're at it, remove the Air Temperature Sensor that is downstream of the MAF, and is a press/friction fit to the rubber air snorkel. This sensor is always covered in a light film of oil as it's downstream from the rubber EGR pipe that connects to the oil filler on the passenger side valve cover (OHV V-6).

NOTE: More than likely need some "security torx" bits to get the two screws removed that hold the MAF to the air cleaner.

Security torx bolt:

Security tork bit:

Merry Christmas!!!

 

[davemazda14]

My 96 was pinging hard until I cleaned the MAF, definitely helped. I never thought of cleaning the air temp sensor.......
One more thing, you can remove the "octane bar" from the harness.... it is a little grey plug that increases your timing by a few degrees. remove it, and it will retard the timing just a taste......you should not feel any performance loss, and should not get a CEL.

 

[lobo411]

K, I finally took the car on a full run (300 mi r/t), and it's still pinging. I'll try the maf sensor today, and see if it still pings on my next full run next week.

 

[FourBinLabs]

Ok, I read through most of this thread but did skim the last few posts. Did you ever try using a higher octane fuel just to see if anything changed? This would at least let you know weather you were getting spark knock or not, helping you narrow down the culprit.

 

[lobo411]

Ok, I read through most of this thread but did skim the last few posts. Did you ever try using a higher octane fuel just to see if anything changed? This would at least let you know weather you were getting spark knock or not, helping you narrow down the culprit.

K...whew! I've been so busy trying to fix a massive oil leak (other thread), so I wasn't able to address the pinging issue. I thought I fixed the pinging by replacing the lower intake manifold gasket. It went away for a day, and now it's back, as bad as ever.

What's been tried/done:
1. Replace single plat spark plugs with double plat (also have new plug wires)
2. Replace all intake manifold gaskets (lower, upper, fuel manifold)
3. Ran 4 bottles of injector cleaner through the tank over the course of a month (Lucas Upper Cylinder, Lucas Fuel Injector Cleaner, Techron, Lucas Upper Cylinder)
4. Cleaned MAF and IAT sensors
5. Radiator flush + oil change

I had NOT yet tried using premium gas, so today I filled up with premium and we'll see if it pings where it usually does--on the Camarillo Grade on the 101 freeway this Wednesday.

I should also mention that I've been burning about 1/4-1/3 quart of oil every 300 miles. I replaced the head gasket 40000 miles ago and had a valve job done + new valve guides installed. I felt only a tiny bit of carbon on the valve stem through the intake ports in the block when I removed the lower intake manifold. I want to switch to high mileage engine oil, but I still have about 4 oil changes left of standard oil in my garage to get rid of.

 

[lobo411]

Most of the plugs looked like this after the monthlong injector cleaner treatments. Fluffy/ashy deposits on one side, and a darkened/brownish area on the insulator. These plugs are single plats, only about 1 yr old.

 

[rb142]

Clean those things up or just grab some new plugs and slap them back in there. The plugs aren't causing the pinging. You may have a lot of carbon buildup on the pistons. Do you know anybody with an inspection camera that could get a peek inside the cylinders?

Pinging can result from the engine running too hot. Is your coolant temp good? Make sure your EGR valve is working. Timing shouldn't be an issue.

 

[lobo411]

Clean those things up or just grab some new plugs and slap them back in there. The plugs aren't causing the pinging. You may have a lot of carbon buildup on the pistons. Do you know anybody with an inspection camera that could get a peek inside the cylinders?

Pinging can result from the engine running too hot. Is your coolant temp good? Make sure your EGR valve is working. Timing shouldn't be an issue.

Sounds good...Might as well run some more Techron since everyone swears by it.

Not really on the inspection camera. I bought a cheapo one for $20 (just a webcam on a wire...plugs into a laptop USB port), but they put a 1/2" cylindrical housing on it because it's meant for pipe inspection apparently.

Coolant temp is good, or even on the low side. The dash gauge hangs out from 1/4-1/3 up in the "normal" range.

I cleaned the EGR just now. It opens fine and there was practically no crud (just a little light tan discoloration on the pistle). I don't have a vacuum pump to test whether it opens at the proper vacuum level, though. I'll probably get one soon because I want to do a fluid exchange on the brakes.

I think you're probably right on the carbon though. That oil has to be going somewhere, and it never used to burn more than 1/4 quart every 3000 miles.

Thanks!