Pinging on highway.

[pitbulldell]

I have a 95 4.0 ex . with 235,000 miles on it that is/was pinging under a load when I found this site.I did all the fixes that I found on here and it runs better but it still pings. I use 89 octane gas.
Last week end while pulling a medium size trailer on the interstate going 60 mph once i started up a hill and I would mash on the gas to mantain speed the trans. would down shift and as the rpm's start to climb the engine would start to vibrate you could feel a lose of power then u would hear the valves rattle.
Coming back without the trailer I did a test.I would get up to 85 mph on a flat surface it was fine, then on hill it would do the same thing.You would feel the vibration then the truck would start to slow down and once you mash on the gas to try and pick up speed you would hear the valves rattling. Anything over 85 it would do it even on a flat surface.
I think it is in ralation to rpm's because I notice anything you do aproaching 3,000 rpm will cause this problem.If you turn off overdrive and drive down the road and stomp on it ,it will pull hard in the lower gears, till 3,000 in the higher gears then the vibration starts and valve rattle will follow.
If you put it in park or neutral you can rev it to the moon with no problems at all.it idles smooth and there is no check engine light on.
Here is a list of all the things I have replace in the last 8 months.
IAC
EGR CONTROL MODULE
THROTTLE POSITION SENSOR
MAF SENSOR
PLUGS
WIRES
CRANK POSITION SENSOR
LOWER INTAKE GASKET
IGNITION MODULE
FUEL FILTER
FUEL PUMP

 

[Crizz]

I can´t find HO2 Sensor... like I wrote, O2-Sensor can be bad w/o giving a DTC . Ran my ´90 XLT with premium fuel and on uphilling it was still pinging until I swapped the O2-sensor. Give it a try if you already haven´t.

 

[Rhett]

I have a 95 4.0 ex . with 235,000 miles on it that is/was pinging under a load when I found this site.I did all the fixes that I found on here and it runs better but it still pings.

But have you de-carboned the engine? I am telling you, that is CHEAP and EASY and it might help things a lot, before spending any more money on it.

I would get up to 85 mph on a flat surface it was fine, then on hill it would do the same thing.You would feel the vibration then the truck would start to slow down and once you mash on the gas to try and pick up speed you would hear the valves rattling. Anything over 85 it would do it even on a flat surface.

I wouldn't be all that concerned about performance of these trucks at over 80-85 mph. What you describe at 85 mph is not abnormal.

You need start by de-carboning the engine. Then go from there.

 

[Creager]

haha yeah, a 4.0 at 85-90 miles per hour is screaming!

235,000 miles, that engine has probably 1/16in thick carbon built up inside. Thats most likely the problem. The intake runners are so smooth with/from the carbon, that the gas shooting out of the injectors starts condensing (into droplets) on the intake-walls. The gas then drips onto cylinder which causes later cylces to pre-ignite; this is called detonation, which is what you are experincing.

Seafoam is probably your best bet, unless you wanna take the intake off and clean it. The best thing to do would be to take the intakes off, and clean them out on the inside to practically bare metal. Then go back and rinse clean them out with warm, soapy water. Cleaning the heads wouldnt hurt, and would most likely help more. You would want to get a machine-shop to clean the heads for you.

I use the brake-booser line to suck the seafoam in. The can of sea-foam has directions printed on the back of it. Bascially, you disconnect the brake-booster-hose while the engine running, then stick it into the can so it can suck like a half a can of seafoam up. The engine will run like crap, and the idea is to practically kill it with sea foam. Once the engine is practically stalled out, turn it off as quickly as you can (maybe a second person would help...) and let it sit for ten minutes. While its off, reconnect the hose. After the 10 minutes have elapsed, start the engine and go for a drive! You should practically smoke out the entire neighborhood.

 

[pitbulldell]

haha yeah, a 4.0 at 85-90 miles per hour is screaming!

235,000 miles, that engine has probably 1/16in thick carbon built up inside. Thats most likely the problem. The intake runners are so smooth with/from the carbon, that the gas shooting out of the injectors starts condensing (into droplets) on the intake-walls. The gas then drips onto cylinder which causes later cylces to pre-ignite; this is called detonation, which is what you are experincing.

Seafoam is probably your best bet, unless you wanna take the intake off and clean it. The best thing to do would be to take the intakes off, and clean them out on the inside to practically bare metal. Then go back and rinse clean them out with warm, soapy water. Cleaning the heads wouldnt hurt, and would most likely help more. You would want to get a machine-shop to clean the heads for you.

I use the brake-booser line to suck the seafoam in. The can of sea-foam has directions printed on the back of it. Bascially, you disconnect the brake-booster-hose while the engine running, then stick it into the can so it can suck like a half a can of seafoam up. The engine will run like crap, and the idea is to practically kill it with sea foam. Once the engine is practically stalled out, turn it off as quickly as you can (maybe a second person would help...) and let it sit for ten minutes. While its off, reconnect the hose. After the 10 minutes have elapsed, start the engine and go for a drive! You should practically smoke out the entire neighborhood.

back in the day when she was running perfect,me and friends would take trips to Tampa and Gainesville from Orlando.I would be following them and it was nothing to cruise at 95 to 110 (when the limiter would kick in) on the Interstate. Stupid I know but I was younger then.

 

[pitbulldell]

Even though I had no codes,I changed the EGR VALVE and the pinging problem is gone.Thanks for your help guys.