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intermittent Knocking sound 06gpgt

B

black06gt

New member
Hey guys im new here. This seemed like a good place to post a question so her it goes. I have an 06gpgt 96k miles stock. I started it up the other day to do some running around and when i got home i heard a slight knocking noise and cant pinpoint where its coming from. shut the engine down started it back and it went away. I drove around again later that day and it seemed fine until i noticed it again at a stop light. When i got home it was gone. I only notice it when stopped and seems to be intermittent. what could cause this? Will try to post a video when i get the chance to but for now some ideas would be helpfull. Thanks guys.
 


Sticky lifter maybe?

I'd add a half quart of trans fluid to the oil and see if it helps clear things up. If the oil is already at the full mark, adding the half quart will be fine. I always ran 5 quarts of oil in a 3800 anyway. Trans fluid is like tide for a motor.
 
i just bought the car a week ago heard the noise and changed the oil last night. mobile1 full syn with a quart of lucas oil syn. thought i heard it this morning at a light but wasnt sure didnt hear it when dropping kids off at school or when i got to work. seems to go away with rpms to and doesnt get louder. will try the trans fluid today. thanks for the quick response man. ps. oil looked good coming out not glittery or anything.
 
So i tried the trans fluid trick still did the intermittent knock. Nothing at start up in the morning while warming the car up. started to knock after driving for a few minutes. Between 1500-2000 rpms it goes away (or cant hear it). After 45 minutes of driving, so dropping the kids of and getting to work it had quit the knock noise. i checked the flex plate for cracks and found nothing. i would think a lower end knock would be consistent and not come and go. Suggestions guys? realy driving me crazy
 




there it is. mind you that is intermittent. it went away before i got home last night and purring like a kitten in the drive threw and car wash.
 
take the belts off one at a time. take the sc belt off, then turn the sc pulley back and fourth qickly, your feeling for play and a click inside the blower snout. if you feel or hear that the sc coupler is bad. fire the engine up belt off to make sure tho.

if the sound is still there sc belt off take the other belt off and fire it up. if its still there its something internal.

if its gone, hand spin all the pulleys, one should be bad.
 


Hooking up a mechanical oil pressure gauge also. Replacing the iridium plugs with al104's. Pulling belts off one at a time. Will check back later.
 
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