Pinging from a 350 Chevy

[siklid1066]

What causes pinging from a motor, if I use a higher octane its not that bad.But the higher the octane the more it costs.

[jkason]

You hit the nail on the head. Octane.

[IA_James]

Octane is a measure of resistence to detonation, also known as pinging. Detonation is caused when cylinder temperatures reach a point high enough to cause the fuel/air mixture to ignite before the spark arrives. Makes stuff rattle around, causes power loss, decreased efficiency, and allowed to go on long enough can cause internal engine damage. A basic tune up might help (properly gapped new plugs, wires, cap, rotor) but more likely your engine needs to have the timing set on it. If that doesn't do it, you may have cooling system issues that are causing increased engine temps that may permit pinging. What 350 is it? TBI, Vortec, carb?

[Lawn-Sharks]

what year is your truck? Is you truck fuel injected or carbed? Are you using E85?

[siklid1066]

94 350 fuel injection

[lawnspecialties]

Excess carbon buildup could be a culprit as well.

90's Fords were notorious for carbon buildup.

[Lawn-Sharks]

Whats the temp guage reading? (210)

[IA_James]

205-210 being what it should be, not necessarily what it is.

[Bill M]

Could be EGR issues also. The GM's coolant temp is 205-210 from the factory, get a 195 thermostat and a fan switch. Make sure the timing has not moved. Yes the higher octane costs more, but only $1.00 or so per tank. Replacement engines are not cheap, so that extra $1.00 for premium fuel may not be that bad.

[siklid1066]

Excess carbon buildup could be a culprit as well.

90's Fords were notorious for carbon buildup.

How do I get the carbon out can it be done without a(Motor Vac)or is this the best way.

[siklid1066]

When the motor is cold its fine when it runs for 15 -20 min it begins.If I use octane boost its fine.But I would like to get to the root of the problem.

[carb454]

Well carbon build-up could be part of the issue causing an effective higher compression ratio... Ignition timing if its too high will cause this, you can ****** the timing to help eliminate this pinging issue but you may notice a slight drop in gas mileage and power.

This could also be cured by water injection were as a line is plumbed from a resevoir through a limiting orafice and connected to the intake plenum or vacuum port allowing a slight mist to mix with the fuel vapor which will quench the detonation... But this is not good for short trips because a cold engine has a condesation factor to overcome and adding water injection will cause even more condensation issues but long term it will clean your engine inside as if it were new also it will add to your power again slight and mileage.

My first choice would be check knock sensor, egr valve , vacuum ports for blockage ,then go lower t-stat 180* ...And run it hard once in awhile to keep her blowed out...does this make any sense :dizzy:

[IA_James]

A lower thermostat would only be a crutch at best. If it's running hot due to something else, it won't help as the thermostat only governs the minimum temperature, not the maximum.

[Petr51488]

Could be EGR issues also. The GM's coolant temp is 205-210 from the factory, get a 195 thermostat and a fan switch. Make sure the timing has not moved. Yes the higher octane costs more, but only $1.00 or so per tank. Replacement engines are not cheap, so that extra $1.00 for premium fuel may not be that bad.

1.00 per tank? supreme is 30 cents more than regular x 34 gallon tank gives you 10.00

[casey humphrey]

do a good tune up! complete tune up ! plugs wires ,pvc, air filter, gas filter ,the works ! and than after that if you can bring to the shop and tell the shop you want a complete injector clean done this is a 2 part process one bottle goes directly in your gas tank , the next bottle has a fitting on it and hooks up to ur injection system and the truck runs at about 2000 rpm and spraying the whole bottle in the system and you watch the crap come out of the tail pipe and after all that do an oil change!! my 97 ranger did this pinging thing and i did all this and it worked very very well no more pinging and it has a lil more pulling power

[zz4guy]

Might want to make a trip to your auto parts store and ask them what they recommend for an additive.

I had a 92 camaro (same engine as yours) that pinged and I added some stuff to the gas and it cleared it up. Apparenlty there was some carbon deposits.

[lawnboy dan]

my 350 has 200k on it and knocks like crazy. i put in a 160 thermostate and it dosnt help. just replaced the timming chain so i know timming isnt an issue. i run 50/50 reg and premium. knock stopped. you prob dont need 100% prem to stop your knock either.

[Ooomwizard]

SEAFOAM!

Go to the autoparts shack and get a can of SEAFOAM! Follow the directions exactly. It will reduce your carbon head deposits. It does work.

I used it on my pinging dodge truck (235K miles) and it smoked so bad during application that I couldn't see my house. That was the carbon being burned out.

No more pinging going up hills, towing my boat or trailer. It's been 6 months since application. No other service done to my truck (except oil change.)

Not starting a Seafoam discussion thread here. But it does works for aging (carbon built up) engines.

Now go back and buy regular gas, yay!