louder than normal tapping from engine - hard acceleration
 

Over the past couple of days I have noticed a louder than normal tapping eminating from my engine.. While at rest (out of gear) there is nothing unusual when exploring the higher rpm's. While accelerating slowly there is nothing unusual through the upper rpm's, but when stomp on it I notice a hard tapping between 5k and redline.. Am I in deep ***** or is this another quirk to deal with?? Oil level and pressure are fine..
Pete
77'Carrera3.0

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www.geocities.com/pcafaro2000/carrera30.html

Perhaps detonation?

Forgive my ignorance, but what is the significance of "detonation"? I understand the whole process as it relates to the operation of the engine, but do you mean something more??
Pete

What does the tapping sound like? Does it sound like a "Pftt", or a "ting"?

Hard to describe in text only.

Retard your ignition 1 or two degrees. Does it continue? Are you running high octane gas (good quality, Shell, Texaco etc)?

If the ping or ting goes away. Then it was detonation. I have heard if it sounds like an exhaust leak under hard acceleration you may have a broken head stud.

Good luck.
Nick

It's a "ting".. Kind of like normal engine sound only amplified.(also hard to explain in text) I know I have my ignition advanced a great deal due to the fact that setting it to the factory specs leaves me with a YUGO performance wise.. I have vacuum lines that are not attached and do not know where they are supposed to be attached. I know that the vacuum lines are supposed to regulate the "power" without messing with the timing. This doesn't read the way it's intended, but I'm sure you guys get my drift.
Pete

Excellent suggestion - using better gas and retarding timing just a tad. Detonation is when the temperature/pressure combination in the combustion chamber gets high enough to spontaneously combust a portion of the air/fuel mixture. Sounds like a leprechaun in there with a brass hammer. It's very bad for your engine.

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'83 SC

Very bad for the engine indeed. I learned this on my first engine a 2.7 that had detonation. I ended pulling the engine and found cylinder #1 and #2 had detonated and shattered the area between the rings sit in the pistons. What a mess that was, smoked the whole neighborhood under acceleration.

Good luck.
Nick

Thanks to all!!! I retarded the timing and added some octane boost to the fuel..... Little gremlins with sledgehammers are dead!!

Pete
77' Carrera3.0

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www.geocities.com/pcafaro2000/carrera30.html

"Glass marbles rattling in a tin can"

I have the same problem...I use 92 octane...the tinging sound comes up at around 4K...under hard acceleration...what is the key to fix this...octane boost?

How do you retard the timing.
Thanks

MJ

You loosen the bolt that's attached to your distributor. You'll quickly notice that you can cause it to swivel in two directions.. Pulling it towards you advances, pushing it away retards.. Hard to describe..

Pete

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www.geocities.com/pcafaro2000/carrera30.html

If your timing is fairly retarded it could be carbon deposits or dirty injectors. Time for some Techron, maybe?

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