LT1 knocking type noise
Thread Starter
Intermediate
Joined: Feb 2003
Posts: 45
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From: Roselle Park NJ
LT1 knocking type noise
Long story short my buddy has a 95 camaro that ran amazing for a stock LT1 camaro(13.93 1/4). He blew the head gasket on the left bank and brought it to a friggin' dealership...duh
. It takes them almost 2 months to finish the car while asking me if I could help with a few of their problems with the job.lol. The day after he gets the car back it starts knocking. I figure that the mechanic just didn't adjust the rockers right. Well, it still knocked after properly adjusting the rockers. I checked all pushrods and checked lifters to see if they collapsed. I did notice that five or so of the lifters (all on the right bank) had no oil in the pushrod pocket. Is it possible that the lifter isn't pumping up any oil?? The car seems to have a slight [I]tick[I] but once it warms up the oil pressure drops lower than he has ever seen it and it starts knocking horribly. Any ideas ???
. It takes them almost 2 months to finish the car while asking me if I could help with a few of their problems with the job.lol. The day after he gets the car back it starts knocking. I figure that the mechanic just didn't adjust the rockers right. Well, it still knocked after properly adjusting the rockers. I checked all pushrods and checked lifters to see if they collapsed. I did notice that five or so of the lifters (all on the right bank) had no oil in the pushrod pocket. Is it possible that the lifter isn't pumping up any oil?? The car seems to have a slight [I]tick[I] but once it warms up the oil pressure drops lower than he has ever seen it and it starts knocking horribly. Any ideas ???
Last edited by 86malcomekonnner; Sep 28, 2007 at 01:01 AM.
Thread Starter
Intermediate
Joined: Feb 2003
Posts: 45
Likes: 0
From: Roselle Park NJ
The noise almost sounds like its coming from the center of the motor and I forgot to menthion that I ran the car the valve covers off and most of the right side didn't have oil feeding to the rockers. But I dont think that its a problem with the bottom end of the motor being as it just started knocking the day after repairs were finished. This car has less than 70k on it and was carefully maintained and cared for.
Thread Starter
Intermediate
Joined: Feb 2003
Posts: 45
Likes: 0
From: Roselle Park NJ
yea but wouldn't a spun bearing make the noise all the time? this doesn't make noise until at oper. temp. and the rockers aren't getting oil...back to my question, is it possible that the lifters aren't pushing oil?
Drifting
Joined: Sep 2005
Posts: 1,867
Likes: 3
From: Pasadena Maryland
If the rockers are dry, then maybe the push rods are clogged or the lifters are? It just gets worse from there.
I have always heard that if you pulled one plug wire at a time and the knock stopped, that was the bad cylinder. I think this works for a rod knock?
I have always heard that if you pulled one plug wire at a time and the knock stopped, that was the bad cylinder. I think this works for a rod knock?
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
When an engine is first started, oil is cool/cold and thicker. This could mask the rod bearing problem so you wouldn't hear any knocking sound.
As the engine heats up, so does the oil. The oil becomes thinner, flows more freely and this could be resulting in the knocking sound to begin.
This is all speculation right now. You can pull the oil filter, cut it open and look for metal particles deep wthin the filter pleats. If you see gold flecks, you'll know it's a bearing problem. Any silver will be the top bearing material, but gold means the wear has gone beyond that.
Draining the oil from the pan can show it too. Look closely at the oil for sparkles; if you see any, that'll be bearing material.
If you DO fine metal it'll be time to drop the oil pan. Look at the inside of the sump for metal pieces; really small, like what gold miners look for when panning for gold.
Last check would be to pull a few rod caps and look at the bearings. That'll remove any lingering doubts.
Hope this helps.
Jake
