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fourthclassC

MA

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Posted: 04/20/21 07:45am Link  |  Quote  |  Print  |  Notify Moderator

Howdy, 02 Ford V10 with 90 k miles. Noticed some pinging under hard acceleration. Tried a tank of premium gas - still there. Wondering if any one has had any experience in changing the Knock Sensors on that engine in a class C. Located under intake manifold and wondering if they can be reached with out removing manifold because of the rear access to the engine when the dog house is removed. Thank s to all who reply.
Jack

Gdetrailer

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Posted: 04/20/21 08:33am Link  |  Quote  |  Print  |  Notify Moderator

Ping and knock are two different things but the sensors on top are designed to detect pinging and the engine computer is suppose to set back the timing to reduce ping.

If you have a code reader you could check to see if the ignition timing is changing during the event.

Something else to consider, you may have a broken (cracked) or leaky exhaust manifold or broken exhaust manifold studs which is very common on the Modular engines. That will also give you a pinging sound. This could be only on one side or it could be both sides.

Loose spark plugs can also sound a lot like pinging, verify the plugs are indeed tight! Early Mod motors have a reputation for spitting out plugs as there were not enough threads in the head and folks didn't use a torque wrench to set them to proper torque.

Extremely important, always use a torque wrench to set the plugs, too little TQ and the plugs will work loose, too much TQ and you risk damaging or stripping the threads on the heads. Each model yr can have different TQ specs, contact your Ford dealer service department, they will most likely need your VIN to verify proper TQ settings.

You want to correct any loose plugs before they get spit out, otherwise it is a Timesert or head replacement repair.

If engine has had a Timesert done, it is possible that it was not done correctly and may be leaking which also can cause a pinging sound which would require that one to need to be redone.

With 90K miles if you have never changed the plugs, you might wish to change them.. Worn or carbon fouled plugs can cause a host of issues.

On edit..

Thought of one other item that can cause a pinging sound, some Catalytic converters on the Modulars around the early 2000s would develop a death rattle when they start failing, sounds like a bunch of marbles in a tin can under heavy throttle..

* This post was edited 04/20/21 08:49am by Gdetrailer *

ScottG

Bothell Wa.

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Posted: 04/20/21 09:18am Link  |  Quote  |  Print  |  Notify Moderator

Knocking and pinging explained: Detonation

I would not shoot the messenger.

Gdetrailer

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Posted: 04/20/21 10:05am Link  |  Quote  |  Print  |  Notify Moderator

ScottG wrote:

Knocking and pinging explained: Detonation

I would not shoot the messenger.


"Wiki"? Yeah, take that with a grain of salt..

No, I am not "shooting the messenger" but here are very distinct sound differences between Pinging and knocking.

While both can be filed under "predetination" pinging is a much "lighter" sound and "knocking" has a much deeper sound which can be confused with things like connecting rod issues.

Pinging is more often caused by excessive spark advance with high compression and too low grade octane of fuel. Reducing the spark advance or increasing octane level typically fixes that.

Knock however is predetonation caused more by too much compression, too much heat in the cylinder, hot spots or carbon buildup (carbon creates hot spots igniting the fuel before it should.. Knock under this situation is not "controllable" much by reduction in spark advance but is more controlled by engine temps.

While THIS website doesn't fully explain the differences in sound between ping and knock they do mention..

"So, spark knock (detonation) is an erratic form of combustion; that occurs when multiple flame fronts occur simultaneously inside a combustion chamber. Detonation occurs, because fuel is subjected to either too much pressure, too much heat or both.

So, instead of a single flame front growing outward smoothly; like an expanding balloon from the point of ignition; multiple flame fronts are generated spontaneously throughout the combustion chamber; as the fuel automatically ignites from heat and pressure. Finally, the multiple flame fronts collide, creating shock waves that; produce a sharp metallic pinging or knocking noise."


Yeah, they call it a "knock sensor" but in reality it is controlling the ping created by too much spark advance..

MFL

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Posted: 04/20/21 10:12am Link  |  Quote  |  Print  |  Notify Moderator

While I don't disagree with above, having the Mod move this thread to TVs may get more response, from the gear heads.

Jerry





ejmorgan

Dixon, CA

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Posted: 04/20/21 10:19am Link  |  Quote  |  Print  |  Notify Moderator

Check for air leakage in the vehicle's climate-control system, which is driven by engine vacuum from the intake manifold. If it is leaking, then un-metered and un-filtered air can be sucked into the engine intake manifold, causing the air/fuel ratio to lean-out. This can cause pinging.

Ed


Ed and Susan Morgan
TT -- 2019 Northwood Nash 24M travel trailer
TV -- 2004 Ford E-350 Extended Van, 6.8L V10, 4-spd. Automatic OD, 3.73 rear axle.
Generator -- Onan 3600 LP

Photo -- Doran Beach in Bodega Bay, Ca.


fourthclassC

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Posted: 04/20/21 10:23am Link  |  Quote  |  Print  |  Notify Moderator

Thanks for all replies. Couple things:
New spark plugs at 68k miles without incident...
Understood - I mean pre ignition here. NO rod knock - understand the difference
It is a E350 chassis on Class C MH
No CEL codes so it is minor at this point
Will check exh manifold for cracks and igniton coils for cracks and high voltage leakage.
How else can I check cat con for failing. There is no loss of power.

Again Thanks for all replies - appreciate the help

ScottG

Bothell Wa.

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Posted: 04/20/21 10:29am Link  |  Quote  |  Print  |  Notify Moderator

Gdetrailer wrote:

ScottG wrote:

Knocking and pinging explained: Detonation

I would not shoot the messenger.


"Wiki"? Yeah, take that with a grain of salt..

No, I am not "shooting the messenger" but here are very distinct sound differences between Pinging and knocking.

While both can be filed under "predetination" pinging is a much "lighter" sound and "knocking" has a much deeper sound which can be confused with things like connecting rod issues.

Pinging is more often caused by excessive spark advance with high compression and too low grade octane of fuel. Reducing the spark advance or increasing octane level typically fixes that.

Knock however is predetonation caused more by too much compression, too much heat in the cylinder, hot spots or carbon buildup (carbon creates hot spots igniting the fuel before it should.. Knock under this situation is not "controllable" much by reduction in spark advance but is more controlled by engine temps.

While THIS website doesn't fully explain the differences in sound between ping and knock they do mention..

"So, spark knock (detonation) is an erratic form of combustion; that occurs when multiple flame fronts occur simultaneously inside a combustion chamber. Detonation occurs, because fuel is subjected to either too much pressure, too much heat or both.

So, instead of a single flame front growing outward smoothly; like an expanding balloon from the point of ignition; multiple flame fronts are generated spontaneously throughout the combustion chamber; as the fuel automatically ignites from heat and pressure. Finally, the multiple flame fronts collide, creating shock waves that; produce a sharp metallic pinging or knocking noise."


Yeah, they call it a "knock sensor" but in reality it is controlling the ping created by too much spark advance..



By shooting the messenger I meant, don't throw out the sensor because it may not be the cause. Not everything is about you.
Also, Knock, ping are all exactly the same thing. You are alone in your suggestion that they are anything else.

You're not helping the OP by trying to show some kind of superiority. Both he and everyone else knows exactly what he's talking about.

* This post was edited 04/20/21 11:47am by ScottG *

Chum lee

Albuquerque, NM

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Posted: 04/20/21 01:20pm Link  |  Quote  |  Print  |  Notify Moderator

ScottG wrote:

"Also, Knock, ping are all exactly the same thing. You are alone in your suggestion that they are anything else."

Not really. (I'm with Gdetrailer here) Clearly pre-ignition and detonation can have similar symptoms/effects, but, their origins are different.

Forget Wikipedia, I suggest you obtain/read a copy of "Internal Combustion Engine Fundamentals 2E" by John Heywood, 2019 edition. The above is a college level required textbook for most accredited Mechanical Engineering Programs/students. Reviewing some Schlieren photography of active internal combustion chambers would also be helpful.

To the OP, you can check your catalytic converter by tapping it lightly (when cold) with a soft mallet. If it sounds like marbles rattling in a tin can, . . . . you need a new one.

Chum lee

fourthclassC

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Posted: 04/20/21 01:28pm Link  |  Quote  |  Print  |  Notify Moderator

Ok. Interesting comment about HVAC control vac leak. Just fixed the vents not opening when the AC was on. Likely to be related. Also will bang on the cat con. to check.

Again thanks for all the help.

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