Pinging 4.0 OHV, tried most solutions.

[~X~]

I don't trust thermostats until I put them in a pot of water & check with a thermometer.....also I change back to 180° in the summer and my trucks still run too hot.

Changing my gold 94 back to 180° tomorrow, been super hot here in Oregon. My red 92 is doing fine with a 180° stat & new water pump and a flush but if I push it climbing I REALLY watch the temps and don't take any chances.

My personal belief is: the trans temps change coolant temps and I frickin hate working on transmissions.

 

[nameiztaken]

I don't trust thermostats until I put them in a pot of water & check with a thermometer.....also I change back to 180° in the summer and my trucks still run too hot. Changing my gold 94 back to 180° tomorrow, been super hot here in Oregon. My red 92 is doing fine with a 180° stat & new water pump and a flush but if I push it climbing I REALLY watch the temps and don't take any chances. My personal belief is: the trans temps change coolant temps and I frickin hate working on transmissions.

everyone seems to go on and on about how the 180 stats ruin fuel economy and cause more issues than they should so I swapped mine back but I’m seriously considering just running the 180.

 

[~X~]

the temp needle never passes the A on NORMAL

My temp gauge rides on "N" and reads exactly 180° on an infrared thermometer at the thermostat housing. I would have no problem giving up 1mpg to run at this temperature......and coax a few more miles out of my transmission. I'm switching to Murray severe duty fan clutches & larger trans coolers this summer. Did I mention I hate working on transmissions?

 

[nameiztaken]

My temp gauge rides on "N" and reads exactly 180° on an infrared thermometer at the thermostat housing. I would have no problem giving up 1mpg to run at this temperature......and coax a few more miles out of my transmission. I'm switching to Murray severe duty fan clutches & larger trans coolers this summer. Did I mention I hate working on transmissions?

I hate transmissions too, mine has a manual so I dont think its contributing to any cooling system issues.

I’m also thinking — nobody with automatics seem to mention having pinging problems... I wonder if the heavy duty fan clutch that comes with the autos helps prevent ping, and that the light duty fan clutch on the 5spd is inadequate?

 

[BKennedy]

My 1994 pings occasionally with regular gas so I run premium whenever possible.

 

[massacre]

My 94 used to ping. I had cracked heads and bad head gaskets. Installed new heads(and a ton of other stuff) and has not pinged since.

 

[BKennedy]

Now that you mention that, I haven't noticed it pinging since I replaced the intake gaskets. Maybe it was sucking more air than I thought.

 

[nameiztaken]

Now that you mention that, I haven't noticed it pinging since I replaced the intake gaskets. Maybe it was sucking more air than I thought.

which gaskets did you replace? I replaced all except the one under the fuel rail which seems fine.

 

[BKennedy]

All of the intake, and the valve cover gaskets. Also rebuilt the injectors. If I'm going to take it all apart, I'm replacing every gasket and rebuilding every part on the way out.

 

[Gary Crist]

"V" engines love to suck oil and/or air from under the manifold
especially, in the corners.

 

[Mbrooks420]

I don't trust thermostats until I put them in a pot of water & check with a thermometer.....also I change back to 180° in the summer and my trucks still run too hot.

Changing my gold 94 back to 180° tomorrow, been super hot here in Oregon. My red 92 is doing fine with a 180° stat & new water pump and a flush but if I push it climbing I REALLY watch the temps and don't take any chances.

My personal belief is: the trans temps change coolant temps and I frickin hate working on transmissions.

Just remove the radiator from the transmission cooling circuit. You can easily replace the radiators cooling capacity for the transmission.

 

[BKennedy]

I bypassed the radiator and added a second trans cooler with a electric fan for hot days and slow crawling off-road. The engine runs much cooler now, usually never getting past the "R" in NORMAL. I like separate systems for my type of rig as I am often 50 miles from a paved road. The trans fluid into the radiator is done to help the trans warm up quickly on very cold days. I don't normally experience them where I travel or live. The few times I have been out expedition camping and it snowed or got real cold, I just let it idle for 5 minutes before I start down the trail. I also think that the trans and engine temps seem to bump up together when they both go through the radiator, which does not happen when separated. I am planning on eventually adding one of those aluminum tube type coolers in the trans lines to add more fluid capacity and help with cooling.

 

[nameiztaken]

Had to drive pretty quick and hard on the highway last night - noticed absolutely no pinging all the way to 75mph and that my temps were staying at 1/3 of the gauge. I’m beginning to think I may have a cooling system issue causing ping.

Also my IAC appears to be defective, can that cause a lean condition? in my head it makes sense.

 

[Nadams01]

I haven’t been able to figure out how much I’m losing per thousand miles yet but its slow enough to not be too concerning. (but definitely more than normal)

Have been running 10w30 Mobil 1 for all oil changes. Bought it in January, don't know what was in it before.

Had to drive pretty quick and hard on the highway last night - noticed absolutely no pinging all the way to 75mph and that my temps were staying at 1/3 of the gauge. I’m beginning to think I may have a cooling system issue causing ping.

Also my IAC appears to be defective, can that cause a lean condition? in my head it makes sense.

Let's kinda retrace back to when you had successfully stoped the pinging. The octane shortening bar retards timing by 5 degrees BTC. If it stopped it either means your not running high enough octane fuel or the icm is requesting a higher ignition time then the fuel can handle. 1 consider your alt if your lower in altitude I would run higher octane. I would put 93 it in next tank see what happens.2 yes replace the pcv and do a oil flush with 50 percent atf. 3 pick up some intake valve cleaner spray aresol can. Seafoam makes a aresol version which is quite good. Go to the throttle body and unplug the 90 degree vacuum line under neath it. While idling the engine at 1500 rpms slowly spray the whole can in without it dying then let it heatsoak. Then start it and rev it untill smoke stops coming out then repeat. There is a TSB from ford on carbon knock on acceleration.

 

[nameiztaken]

Let's kinda retrace back to when you had successfully stoped the pinging. The octane shortening bar retards timing by 5 degrees BTC. If it stopped it either means your not running high enough octane fuel or the icm is requesting a higher ignition time then the fuel can handle. 1 consider your alt if your lower in altitude I would run higher octane. I would put 93 it in next tank see what happens.2 yes replace the pcv and do a oil flush with 50 percent atf. 3 pick up some intake valve cleaner spray aresol can. Seafoam makes a aresol version which is quite good. Go to the throttle body and unplug the 90 degree vacuum line under neath it. While idling the engine at 1500 rpms slowly spray the whole can in without it dying then let it heatsoak. Then start it and rev it untill smoke stops coming out then repeat. There is a TSB from ford on carbon knock on acceleration.

Thanks for the reply.
I actually do most of my driving at or near sea level (10ft-1000ft, sometimes up to 2,500) so thats a very interesting thing to consider. I did see another post regarding ping on the 4.0 from someone local.

It does not ping on 91 octane which is the highest available here, with or without the octane bar installed.

I have tried the seafoam stuff (twice), as well as techron. Crankcase is clean.

As annoying as it may be, I’ll probably just live with it and run 91. It gets noticeably better gas mileage anyways.

 

[nameiztaken]

Can now add a new intake air temp sensor, MAF sensor, and throttle body gasket to the list of things that did not fix it.

 

[Nadams01]

Thanks for the reply.
I actually do most of my driving at or near sea level (10ft-1000ft, sometimes up to 2,500) so thats a very interesting thing to consider. I did see another post regarding ping on the 4.0 from someone local.

It does not ping on 91 octane which is the highest available here, with or without the octane bar installed.

I have tried the seafoam stuff (twice), as well as techron. Crankcase is clean.

As annoying as it may be, I’ll probably just live with it and run 91. It gets noticeably better gas mileage anyways.

Interesting. When you say you tried seafoam did you use it in the gas tank or sprayed into that vacuum port? You wanna spray it to try to remove carbon build up on the intake valves. Also your supposed to be ok running 87 according to the manual. But let's think about possible sensors that can change ignition timing. The big one is your baro sensor or barometric atmosphere pressure sensor. This is a RAM sensor so each time the vehicle is started the value resets to a base value and usually sets a frequency of what it believes to be the pressure in inHG within 5 sec of starting. After that the sensor will not update the values unless a hard sustained pull above 3.5k rpm in second gear is completed. If you dont rag on it once it won't update. I would start here as these sensors have been the cause of many gremlins. If it's giving a out of wack pressure to the pcm it's gonna advance ignition timing accordingly. Here in CO about 5.5k feet it's usually 24 to 23 inHG. Does your tcc solenoid work? If not it's the baro because one of the parameters for tcc engagement is a atmospheric pressure above 22 inHG.

 

[Gary Crist]

When you finally pull the heads, you will find the intake valves caked with carbon
as well as the combustion chambers caked too. I have never seen anything short
of glass blasting or hot-tank for the removal of built-up deposits. 15+ years of deposits
can't be removed with down the throat chems....

You should have of seen big blocks gunking up in the mid 70's. They would run-on forever
from hot carbon glowing in the combustion chambers.

I do not think changing parts will ever help stop your pinging.

 

[nameiztaken]

a new engine coolant temp sensor seems to have made a notable improvement, but the ping does still remain on hills.

 

[nameiztaken]

Updated list of information:

Engine pings less on 91 octane, pings moderately on 87. Does not ping with octane bar removed, only at high RPM (3500+). Engine pings badly at WOT. Engine pings at its worst when up to operating temp. There are NO cel codes.
Mobil 1 10w30 oil. Vehicle is NOT EGR equipped.

• New coolant
• New tstat (197f)
• New fan clutch
• New spark plugs (autolite x2, now ngk)
• New plug wires x3
• New coil pack
• New ECT
• New IAT
• New MAF x2
• New felpro intake manifold gaskets (all)
• New PCV x2
• New PCV Catch Can
• New IAC
• New fuel filter
• Cleaned throttle body
• Added BAP sensor to empty slot, now MAF and BAP sensor equipped. No idea if adding BAP sensor does anything.
• Used Seafoam x3 cans per Ford carbon TSB
• Used Techron in fuel x4
• Used Marvel Mystery Oil in oil before change
• Checked fuel pressures, 28psi idle / 38 psi WOT
• Checked TPS voltage, appears to function correctly
• Could not locate any vacuum leaks - cannot perform smoke test.

I’m at a loss