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Pinging/knocking

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  #1  
Old 12-06-2004, 04:48 AM
alvin's Avatar
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Default Pinging/knocking

I have a 95 Sedan Deville and have had a knocking for 3 months. I took it to cadillac they said I needed a deep cleaning. I ran 3 tanks with BG-44 and I still have the probelm. It does not ping or knock when cold, when revving in neutral, in reverse with brake depressed or in park. Only when warm and in forward gears. I'm starting to think it could be my torque converter but I'm not sure. Any suggestions..........
 
  #2  
Old 02-04-2005, 11:48 AM
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Default RE: Pinging/knocking

My '97 Eldo ETC knocked occasionally. The dealer, and it's an excellent dealer with a top-notch service department, indicated it was common with the Northstars - carbon knock. I was always a little skeptical of that interpretation since my cars are exercised whenever the opportunity presents itself, which is frequently in this part of the country. That engine never needed to be blown out. The dealer ran cleaner through the engine which reduced the racket but didn't completely alleviate it. I never noticed any performance reduction and so ignored it going forward. The Eldo always ran like a top until we used it on a trade.
 
  #3  
Old 02-22-2005, 05:40 PM
Join Date: Feb 2005
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Default RE: Pinging/knocking

Have you received any feedback or find out what the problem could be? I have a 97 Eldo w/58k and does the same thing. Only when motor is warm. I run only premium Chevron and have tried different fuel and had teh dealer service the injectors, changed fuel filter. No explanation at this point. I take exceptional care of my car and am stumped! If you find a solution please let me know. Thank you
 
  #4  
Old 07-07-2005, 09:19 PM
Join Date: Jul 2005
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Default RE: Pinging/knocking

Old Jaguars had the same problem. Carbon build up would cause knocking. There are two ways to get rid of it. Remove and clean the heads or do the old water down the carb trick. The engine needs to be hot. It is a good idea to put some cardboard over the radiator to get the engine real hot. With the engine running trickle water into the carb or into the throttle on fuel injected cars. Keep the engine running while adding the water. Be careful not to add to much water at once or you could hydraulically lock your cyilinder and destroy the engine. It would probably take a lot of water to do that. So don't use the garden hose. The water explodes on the hot cardon and some how cleans it off. If you have ever seen a head off of a car with a head gasket leak you would notice how clean the cylinder with the leak was. I worked with a guy with a PHd from MIT , who had many engine pattents , a mad scientist, and he said the the water method worked.
 
  #5  
Old 07-29-2007, 10:25 AM
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Default RE: Pinging/knocking

Hello All!
I am inquiring if anyone has found a solution to the pinging/pre-ignition/detonation issue.
My 1996 Seville STS has 172,000 miles. It has run perfectly for the six years I have owned it.
Six years ago I installed new wires, plugs and an EGR valve.

I moved from the North to Charlotte, NC a few days ago, and since then, the Northstar has caught a serious case of detonation. It runs well, but sounds like it is going to blow any minute.

The outsidetemperature is in the 90s here which is about 15 degrees higher. The temperature guage used to stay pointing straight up, but here in North Carolina where the weather is hotterthe guagepoints to the first mark past straight up when at operating temperature.

So the car runs hotter now in the heat. There is not any coolant loss.

I have considered taking out the thermostat, or finding a way to turn on the cooling fans earlier in an effort to keep the engine cooler. I have some fuel injector cleaner in the tank along with some 93 octane fuel. Neither of those seemed to have helped yet. I have always run 89 octane, but will run 93 or 94 for now on.

Could the crank position sensors be causing the spark to occur early?
Could the knock sensor have failed? (if there is one)
Is it unusual for the temperature guage to move past half-way (straight-up)?

How do I stop the pinging?

Jon
 
  #6  
Old 07-29-2007, 11:01 AM
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Default RE: Pinging/knocking


your knock sensor is highly suspect. i be parking this baby until you fix it or you will damage internals.
you may also find some relief in the high octane fuels, but although it may allow you to operate it,
THAT is not a solution for this. if the sensor failed, it may even ping even then.

your next problem is why is it running hotter? ambient there does not justify that.
need to find out why. however, i dont beleive that is a reason for the ping if the sensor is working.



ORIGINAL: jonrodman

Hello All!
I am inquiring if anyone has found a solution to the pinging/pre-ignition/detonation issue.
My 1996 Seville STS has 172,000 miles. It has run perfectly for the six years I have owned it.
Six years ago I installed new wires, plugs and an EGR valve.

I moved from the North to Charlotte, NC a few days ago, and since then, the Northstar has caught a serious case of detonation. It runs well, but sounds like it is going to blow any minute.

The outsidetemperature is in the 90s here which is about 15 degrees higher. The temperature guage used to stay pointing straight up, but here in North Carolina where the weather is hotterthe guagepoints to the first mark past straight up when at operating temperature.

So the car runs hotter now in the heat. There is not any coolant loss.

I have considered taking out the thermostat, or finding a way to turn on the cooling fans earlier in an effort to keep the engine cooler. I have some fuel injector cleaner in the tank along with some 93 octane fuel. Neither of those seemed to have helped yet. I have always run 89 octane, but will run 93 or 94 for now on.

Could the crank position sensors be causing the spark to occur early?
Could the knock sensor have failed? (if there is one)
Is it unusual for the temperature guage to move past half-way (straight-up)?

How do I stop the pinging?

Jon
 
  #7  
Old 07-29-2007, 11:04 AM
Stealth's Avatar
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Default RE: Pinging/knocking


it may be preventable.

read this:
https://www.cadillacforum.com/m_7154/tm.htm

ORIGINAL: 67SEDANDEVILLE

Old Jaguars had the same problem. Carbon build up would cause knocking.
 
  #8  
Old 07-30-2007, 10:37 AM
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Default RE: Pinging/knocking

Hey Jonrod: Something to think about. If you changed altitude very significantly when you moved you may require retuning of your engine, timing etc. Summer fuel is always an issue as well because they don't put in as many additives as is required for winter driving. The fuel will contain a higher percentage of water and hence change the burning characteristics of your fuel. Hope you can get the thing solved.
 
  #9  
Old 07-30-2007, 10:47 PM
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Default RE: Pinging/knocking

Hello brougham1 and Stealth,

Thanks for the good ideas. I will put in a new knock sensor tomorrow.

I have been occasionally doing WOT anyways. Not as often lately, but I just drove 800 miles and did have the petal to the floor a bunch of times.

I did put on new spark plug wires yesterday. That made a difference. It idles smoother and is perkier. Two or the wires appeared to have burned through and must have been arcing to the aluminum head at least intermittantly. The new wires also seemed to have greatly reduced the pinging.

The pinging is still occuring but not as much. Tomorrow I will change the knock sensor and put in new plugs. That knocking has probably damaged one or more of the plugs.

I actually cannot believe the engine has withstoodthe knocking. It would have killed an ordinary engine. I have kind or ruled out the higher operating temperature as being a problem. It really is not running much warmer than in the north, the cooling fans so come on when the guage reaches the first mark past half way. The needle never goes anywhere near the red and there is not any loss of coolant.

I am at a higher altitude.

If the knock sensor does the trick, I will let you know.

Thanks again,
What a knowledgeable group!
Jon
 
  #10  
Old 08-01-2007, 07:41 AM
G.A.R.Y.'s Avatar
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Default RE: Pinging/knocking

Hey Jon
FYI
Remember that just putting the pedal to the metal is not necessarily our prefrered way of accomplishing WOT. Click on link on the Stealth post if you haven't already. We have discovered recently that on some sites WOT's are opposed, however their definition of WOT may be different then what we have posted.
 


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