knocking sound that comes and goes?
11-07-2011, 07:39 AM
#1
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knocking sound that comes and goes? What would cause a top end knock to come and go? If you let the car sit for an hour or so it will go away. I can only think its a lifter the is bleeding down and pumping back up?
11-09-2011, 01:46 PM
#5
could b a worn out valve spring causing the valve to float and messing up you preload dont always blame the lifter right away, do you notice a drop off in power at certain rpms
11-09-2011, 04:27 PM
#7
Does it make more or less noise when the engine is at full operating temp vs when it is cold?
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11-09-2011, 05:48 PM
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It will knock for a second when it first starts then goes away and stays quite untill it does this. It has only started when the eingine is at full temp and I havd been driving for a little while.
I have shut it down for an hour and come back to start it after an hour at the earliest, It will knock for a couple seconds then go away.
It has done it twice just driving around town for 30 mins or so. Shut it down for an hour restart and no noise
Then at the end of my hour and a half drive to milwaukee it was real bad. Parked it, went to my concert, came back out after a few hours expecting to have to call a tow truck and it didnt make a sound and was fine the entire drive back.
The only other thing I have noticed is the oil pressure seems to jump around quite a bit wether the engine is cold or warm. But it has never dropped below 30 psi.
I have shut it down for an hour and come back to start it after an hour at the earliest, It will knock for a couple seconds then go away.
It has done it twice just driving around town for 30 mins or so. Shut it down for an hour restart and no noise
Then at the end of my hour and a half drive to milwaukee it was real bad. Parked it, went to my concert, came back out after a few hours expecting to have to call a tow truck and it didnt make a sound and was fine the entire drive back.
The only other thing I have noticed is the oil pressure seems to jump around quite a bit wether the engine is cold or warm. But it has never dropped below 30 psi.
11-10-2011, 12:06 PM
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It sounds more like a loud rod knock but its faster like its valve train. Its not nothing I thought the motor was about ready to say adios the first time I hear it. It is VERY LOUD
11-10-2011, 12:20 PM
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I was going to say lifter preload. but if it's a loud sound and still a stock engine. Could be "piston slap" I read somewhere that pre 2000 cars had that issue. Just an idea. How many miles are on it?
11-10-2011, 02:33 PM
#13
If the sound seems to come out the exhaust pipes as well it probably just lifter noise as others have said.
What weight oil you running? Mine used to do this a lot when I was running 5-30 Royal Purple. Try running a thicker weight oil and see if it goes away.
What weight oil you running? Mine used to do this a lot when I was running 5-30 Royal Purple. Try running a thicker weight oil and see if it goes away.
11-20-2011, 03:56 AM
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Thoughts Not to hijack ur thread but my car is doing the same thing, the knock comes and goes.....it seems like its on the driver side back by the exhaust....if it is lifter noise how do I get it to stop?
