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Pinging in my ear's

G

gary b.

Guest
This pinging is driving me nut's:hb
So far i have done the following:
1) fresh coolant
2) cooler thermostat
3) retarded/advanced timing (no change)
4) exposed air filter
5) put in colder spark plugs (from R45TS to R43TS)

Any & all help please,

Could a dirty or bad carb. cause ping ?
It's a 78 stock motor, needs many pumps to fire up, but really
run's great!

Thank's everyone! gary.
 
Joined
Jan 1, 2002
Messages
7,246
Location
Washington, Michigan
Corvette
'67 Marina Blue Convertible
Did the pinging start recently, or has it been happening for a long time? Any work done on the engine recently? Under what driving conditions does it occur? Pinging is generally a spark timing issue rather than a carb issue, unless it's REALLY leaned out. Pinging usually results from over-advanced timing - breaker plate stuck, advance weights stuck, vacuum advance not working, etc.
 
G

gary b.

Guest
Did the pinging start recently, or has it been happening for a long time? Any work done on the engine recently? Under what driving conditions does it occur? Pinging is generally a spark timing issue rather than a carb issue, unless it's REALLY leaned out. Pinging usually results from over-advanced timing - breaker plate stuck, advance weights stuck, vacuum advance not working, etc.

Thanks John!

The pinging has been there since i got it 4 months ago.
No work done to the engine, & it's totally stock.
It pings under any & all driving conditions, taking off from a stop
light, medium, heavy acceleration, just dosent matter.
Accelerating from cruising speeds, still there.
The only time it does'nt ping, is when the engine is off & the keys
are in my pocket.
Timing is set to factory specs.
Everything in the distributor seems to be in good working order,
When i unplug the vaccuum advance, the idle goes way down
until it nearly stalls.

One more thing, ITS VERY EMBARRASING!!!!

Thanks for helping me out! gary.
 
D

Dave L.

Guest
How many miles are on your motor Gary?I had a similar problem when I got my car.A new timing chain and gears was the fix.I had 101,000 on the original gear set.It might be something else to consider.

Dave
 
F

fc3

Guest
My 72 had what I thought was a ping, when accelerating... it turned out to be the flywheel cover touching the flywheel making the pinging noise. It was easily fixed by removing the flywheel cover and hammering it back out. Fred.
 

Zektor

Well-known member
Joined
Aug 28, 2002
Messages
100
Location
United Kingdom
Corvette
1982 Silver Coupe (Sold!), New C5 in 3 weeks!
Apart from the physical contact of moving parts as suggested in previous posts. It could be that your car needs a de-coke. A build up of crap in the top of the engine can cause the very problem you are describing.

Cheers
Dazza
 
G

gary b.

Guest
My motor has 55,637 original miles on it .
I forgot to mention that it is an automatic trans. if that makes any difference.
Interesting about the flywheel cover, i'll check.
I know for a fact that the previous owner only drove very short
joy rides around town, for the 15 years he owned it, carbon
build-up makes sense, would

G.M. Top Engine Cleaner remove
that ?
Thanks to,
Dave-- Fred-- Dazza--JohnZ !
 

Zektor

Well-known member
Joined
Aug 28, 2002
Messages
100
Location
United Kingdom
Corvette
1982 Silver Coupe (Sold!), New C5 in 3 weeks!
There are many products on the market that do try to shift carbon deposits. If it's very bad you may need to use the product 2 maybe 3 times before a good result is obtained. Another question, what fuel do you use, regular or premium/super? The premium/super gas is supposed to be better for keeping your engine clean due to a better overall burn. The higher octane also can relieve pinking.

Cheers
Dazza
 
G

gary b.

Guest
what fuel do you use, regular or premium/super

I thought fuel would make a difference too, so i tried
Ammoco Ultimate (93 octaine) , almost done with my 2nd tank
full and absolutly no change.

Thanks, gary.
 
Joined
Apr 29, 2001
Messages
2,141
Location
Rio Rancho, NM
Corvette
1981 HD Suspension; ZN1 Option
Spark plug condition

Gary,

I have a hunch that if you look and analyze the condition of your spark plugs, then it could help determine if you have too hot of a spark plug (long spark plug insulator nose -less heat absorbtion) or perhaps a too cold spark plug (short spark plug insulator nose -more heat absorbtion).

The torque converter cover contact suggestion is interesting, but the key is to determine if the "pinging" sound increases linearly with the RPM. If the sound remains constant or changes very little with RPM, then I would guess that this is not your problem.

I agree with JohnZ, and your ignition components should be looked at closely.

One last thing, the spark plug reach into the combustion chamber can determine how your fuel/air mixture burns. Since you say that the engine is very much stock, this could be unlikely; however, the only way to be sure is by checking your head casting numbers to make sure that the heads are OEM for your engine.

One drawback is that by reading the spark plug condition one intruduces the fuel/air mixture component into the analysis. I am not sure if the 78 had an oxygen sensor, but sensors have been known to cause all kinds of problems, for they are "upstream" of the system in most cases. Meaning that they sense, and then they "tell" other components how to operate.

Just trying to help....
 
G

gary b.

Guest
if the "pinging" sound increases linearly with the RPM. If the sound remains constant or changes very little with RPM,

THANK'S GERRY.

The pinging does not increase, it stays constant during all
acceleration runs.
I was wondering if heaver advance springs in the distributor
would help any? The plugs i took out were in great shape, but i put in colder ones anyway,(
 
G

gary b.

Guest
OOP'S i hit the wrong key.
:duh

the plugs i took out were R45TS the ones i put in are R43TS
It did not change even a little bit!
Is there any way for me to check the distributor more accurate?

Please continue your ideas, we might be on to something!

Thank's again, everyone!!!!!!!!!!!!!!!!!!! gary.
 
Joined
Apr 29, 2001
Messages
2,141
Location
Rio Rancho, NM
Corvette
1981 HD Suspension; ZN1 Option
valve/lifter noise

Gary,

You have not mentioned if you're getting any kind of lifter noise to indicate a bad hydraulic lifter. It is easy to hear. You'll get a mechanical steel sound :bang if the lifters are sticky or do not load-up like OEM. If the car is cold, then this sound is sometimes not uncommon, but it should go away when it warms up.

One nice trick is to place a long screw driver on certain parts of the engine to see if you'll get a corresponding vibration/mechanical tick to the pinging sound. Be careful with moving parts, Gary, and make sure you don't ground a hot wire with the screw driver :nono.

One last thing...valve clearances go out of whack when lifters go bad, so keep this in mind if you do find a possible bad lifter. Timing will be hard to attain in some cases when these parts have some slop. Timing chains and vaccum leaks can also waste you alot of time if not examined.

Nevertheless, I am trying to keep the ideas simple, for most of the times it is something relatively easy that wrecks havoc with most vehicles.

Just trying to help...
 

cntrhub

Well-known member
Joined
Jun 17, 2002
Messages
390
Location
North Hollywood, Ca.
Corvette
Miss my '62 & '80 4- Sp. Vettes
Get a timing light and check for advance mode when you rev off idle. If there is no lag to full advance, and moves when engine rpm goes higher, I don't see the need for heavier advance springs. The Dist. runs off the cam and it will show if you have a cam chain problem. The timing will bounce around eratic at idle. Sustained throttle, the chain is loaded on one side. Overadvanced ignition timing causes "pinging."
I am leaning on Zektor's "decoke." Check compression. If you have very high compression on a few cylinders than is normal psi., I think carbon build-up might be the cause? You didn't mention anything about the engine still running, (with the key in your pocket....<<< l laughed at that line) after the engine is turned off? Usually carbon will act as a glow plug and keep sparking the fuel.
The most volatile fuel is right at your kitchen sink faucet. If you could devise a way to spray a stream of water into the engine, (engine running, of course) the steam will blow away that carbon and clean the piston dome, and cylinder chamber like there was never a smudge of carbon on it. Excessive carbon deposits on pistons and cylinder heads cause "pinging."
The only real way to check how the engine is running rich or lean wise, is to: Red line the engine at a load, kill the engine and pull a spark plug. This is what's known as a "Plug Chop." Just revving the engine in the driveway and turning off the engine is not the proper way. Look all the way to the bottom of the porcelain inside the plug. If the porcelain is white... it's way too lean! If black and sooty.....too rich. If the color is light brown...just right. Gray in color.....best running Vette in town. Of course you can't turn off the engine without setting the steering lock if you went to far. And you will have a hard brake pedal because you lost vacuum trying to slow down. What you are looking for, is a lean running engine. If you pull the plugs now, you could get a pretty good idea what to look for in color.... without doing a "plug chop" and endangering you or others. Basically, you are looking for a "lean" running engine. A lean fuel mixture causes "pinging."
These are 3 common ping problems to chase. Good luck.
 
S

sac001

Guest
Gary,
You're getting alot of good info here, just hope it isn't information overload. ;)

First you really need to identify the noise. Is it a pinging sound under a bit of load (when you stp on the gas, sounds like loose marbles in the engine) or is it a tapping sound that you hear at idle and gets worse (or more rapid) with engine RPM increase.

Get someone to rev the motor slightly while you look at and listen to the motor run at idle, try to define if it is tapping or pinging. Then have your helper power brake a little and listen again, again try to define if it is tapping or pinging.

The lifters will tap at idle, probably loud enough for you to identify the noise. When power braking the lifters will still tap, but the noise should only increase in tempo, not get much louder.

On the other hand, with the engine at idle in neutral (or park) you probably won't hear any pinging. When you power brake the pinging will get louder and worse as your helper adds throttle.

Good luck, and keep us posted.

Steve :w
 

cscarlson

Well-known member
Joined
Jan 27, 2002
Messages
876
Location
SYRACUSE ,UTAH
Corvette
2003 50Th Corvette
Mine did this and i had the hydraulic lifters adjusted and no more
noise.
 
G

gary b.

Guest
Thank's alot EVERYONE, for all the help & advice!!!!!!!!
Great bunch of people here at:CAC

It's definetly pinging, ( loose marbles) at idle, the motor is totally
silent and runs like a swiss watch. Zero lifter noise.
The ping does not increace with acceleration, it stays constant
from medium to full throttle. I did notice though, it goes away
compleatly at full tilt giddy-up. :confused gary.
 

Evolution1980

Well-known member
Administrator
Joined
Feb 25, 2002
Messages
4,302
Location
Cleveland, Ohio
Corvette
ZZ4, 700R4, Steeroids rack & pinion, VB&P Brakes
Re: Spark plug condition

GerryLP said:
I am not sure if the 78 had an oxygen sensor, but sensors have been known to cause all kinds of problems, for they are "upstream" of the system in most cases. Meaning that they sense, and then they "tell" other components how to operate.
Just trying to help....
No O2 sensor because no computer. (yea!!! :L)

You should always be running high octane (at least 92). Anything less and you will ping, as well as get plenty o' carbon buildup. Too much carbon buildup and all the high octane ain't gonna clean it. You may want to try some Valvoline Throttle Bottle [and Fuel injector) Cleaner. Buy two bottles. Run them through one tank at a time. That may help somewhat. Yes, I realize you don't have a TB or FI's, but it's the cleaner you need (possibly). It still works the same on the carb jets, engine internals, etc...

Other than that, I don't have your problem and it was info overload reading through all the help offered thus far...hahahah... this place rocks! :_rock

:CAC
 
S

sac001

Guest
If it is definately pinging, with new plugs & timing correct, pull the Air Cleaner cover and check out the carb. I agree you probably have some carbon build-up inside the motor, and the fuel additives will eat away at that, but your carb is probaly gummed up as well. Especially if the pinging goes away at full throttle (all four jets pumping).

Try to clean up the carb a bit with Carburator cleaner (spray a little at a time into the carb with the car idling, the motor will stumble when you've sprayed too much then wait a few seconds and shoot another squirt). You should see the carbon loosen up almost immediately in the carb as you do this. Clean as much of the carb as you can see.

Then, use the additive for a while and see if that helps.

Good luck, & keep us posted.

Steve :w
 
S

secondchance

Guest
You might also try "GM Engine Top Decarbonizer". This is sold at most GM dealers. Over the years some engines builds up carbon deposits and during the compression stroke, these carbon deposits could glow like glow plugs in a diesel engine prematurely igniting the mixture.
Your pinging condition seems rather severe and if I were you, I would run decarbonizer twice at least and see if it makes any difference.
 

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