New engine, knocking noise
New engine, knocking noise Hey all
Got my car back from being rebuilt. Pistions 5+7 were shot. I went with a used block that had nothing but the pistons in it. It had about 13K miles on it. The car was rebuilt using the parts from my other engine. We did however upgrade the pushrods to hardend ones, LS6 lifter, and an LS6 oil pump. Everything else was the stock LS1 parts off my old engine. My car is a 2002. The "new" block is out of a 2001
The car has a knocking noise at 1700rpm when the engine is under load. It does not seem to do it when I lightly rev it sitting still. The noise will quickly disappear once you hit 2000 rpm. It is most noticeable when the car has been sitting for a while and has completely cooled off. The noise will eventually go away but I can usually still hear it even when the coolant temperature is up the normal. For example. On the way home from work yesterday, I could hear the noise right away. I drove the car for about 5 mins at 50 mph. At a stop light, I heard the noise when I pulled away. After driving the rest of the way home (50-50 city/highway) the noise was gone the next time I came to a stop and pulled away.
My first instinct was piston slap however what I could find tells me that I should be able to hear it at normal idle speed and that it should go away within 30 secs to a minute or so. It does neither. I've contacted the previous owner of this block to see if it made any noise for him and I'm awaiting a response. Thanks for any insight guys!
Got my car back from being rebuilt. Pistions 5+7 were shot. I went with a used block that had nothing but the pistons in it. It had about 13K miles on it. The car was rebuilt using the parts from my other engine. We did however upgrade the pushrods to hardend ones, LS6 lifter, and an LS6 oil pump. Everything else was the stock LS1 parts off my old engine. My car is a 2002. The "new" block is out of a 2001
The car has a knocking noise at 1700rpm when the engine is under load. It does not seem to do it when I lightly rev it sitting still. The noise will quickly disappear once you hit 2000 rpm. It is most noticeable when the car has been sitting for a while and has completely cooled off. The noise will eventually go away but I can usually still hear it even when the coolant temperature is up the normal. For example. On the way home from work yesterday, I could hear the noise right away. I drove the car for about 5 mins at 50 mph. At a stop light, I heard the noise when I pulled away. After driving the rest of the way home (50-50 city/highway) the noise was gone the next time I came to a stop and pulled away.
My first instinct was piston slap however what I could find tells me that I should be able to hear it at normal idle speed and that it should go away within 30 secs to a minute or so. It does neither. I've contacted the previous owner of this block to see if it made any noise for him and I'm awaiting a response. Thanks for any insight guys!
I'm assuming it was. The car was taken to a very well known and reputable shop. I know that there were no corners cut. Basically the only thing bottem end wise that is from the new motor are the block and pistons. Everything else, including the cam and crank, were taken out of my old motor and put in this one.
Just a guess and without hearing it or being there, I'd say rod knock! I'd have to hear it to verify though, it's very noticeable and once it happens to you, you'll never forget that sound again.
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From: ne ct summer,naples in the fall
rod knock- ditto
years back when i was in the turbo buick scene i bought a brand new short block (89 turbo trans am short block- cross drilled mains) from a buick dealer with all new buick engine parts plus champion heads blah, blah...took it too a reputable or so i thought builder/tuner- Eric Rankin- *******, ********- he assembled my parts and in two weeks go my car back- with in 100 miles i developed a knock. too it to a good guy in fall river, ma -Tony. he pulled the covers i had 5 bent push rods- seems the dumbass Eric assembled the engine and when he got to the rockers- just tossed them on, the buick 6 has intake and exhaust rockers- different. they were replaced and now the knock was very pronounced. the pan was pulled along with the main caps and VIOLA- wiped- the crank main journals had groves. Seems that ********** ERICK RANKIN swapped my bottom end for one of his junk 30 over shot bottom ends- he tossed in new bearings and when they wore down my knock developed. i was ready to tear him apart had it not been for Tony. Tony had a friend who worked for GM and was able to get a 100% warrantee on my bottom end. had it not been for Tony i probably would be in a 8x10 cell.
bottom line- it is very, very hard to trust anyone regardless of who they are or their reputation.
years back when i was in the turbo buick scene i bought a brand new short block (89 turbo trans am short block- cross drilled mains) from a buick dealer with all new buick engine parts plus champion heads blah, blah...took it too a reputable or so i thought builder/tuner- Eric Rankin- *******, ********- he assembled my parts and in two weeks go my car back- with in 100 miles i developed a knock. too it to a good guy in fall river, ma -Tony. he pulled the covers i had 5 bent push rods- seems the dumbass Eric assembled the engine and when he got to the rockers- just tossed them on, the buick 6 has intake and exhaust rockers- different. they were replaced and now the knock was very pronounced. the pan was pulled along with the main caps and VIOLA- wiped- the crank main journals had groves. Seems that ********** ERICK RANKIN swapped my bottom end for one of his junk 30 over shot bottom ends- he tossed in new bearings and when they wore down my knock developed. i was ready to tear him apart had it not been for Tony. Tony had a friend who worked for GM and was able to get a 100% warrantee on my bottom end. had it not been for Tony i probably would be in a 8x10 cell.
bottom line- it is very, very hard to trust anyone regardless of who they are or their reputation.
I'm starting to hear it a bit longer now. I also can hear a very slight tick noise at idle when the car is hot. I'm not going to drive it anymore until I can get it back down to the shop. If I had to say where it's coming from, it sound top end.
I really have a hard time believing this shop screwed me. They are a sponsor on here and have a great rep. Many, many people recommended them. Including the guy I bought the block off of.
I really have a hard time believing this shop screwed me. They are a sponsor on here and have a great rep. Many, many people recommended them. Including the guy I bought the block off of.
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Teching In
Joined: Oct 2008
Posts: 40
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From: The 717
Mini, where in lanc lanc do you live? I actually grew up in the sothern end and went to Slowlanco HS, but I live in Philly now. Also, what shop did you take it to?
I had a similar noise and I thought it was either a lifter or just loud piston slap, but it would go away after the engine was running for a while. Now, I'm rebuilding the motor because I have a hole in my block!!! I'll be pulling the motor out next week, but as of now I really don't know what caused it. Good luck!
I had a similar noise and I thought it was either a lifter or just loud piston slap, but it would go away after the engine was running for a while. Now, I'm rebuilding the motor because I have a hole in my block!!! I'll be pulling the motor out next week, but as of now I really don't know what caused it. Good luck!
I dunno how the piston could get loose just from sitting. The previous owner said he had no noises from it at all.
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From: ne ct summer,naples in the fall
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From: BFE
Ok, just so I get this straight.
You took a shortblock that had pistons and transfered your crank and rods over?
Did you put new bearings (crank, rods) in and rebalance/blueprinted the assembly?
You took a shortblock that had pistons and transfered your crank and rods over?
Did you put new bearings (crank, rods) in and rebalance/blueprinted the assembly?
Yes the only thing the new shortblock had in it was the pistons. I am assuming that new bearings were used but have no idea about the rebalance or blueprinting. The shop that did the work is on vacation right now so I probably can't get ahold of them until monday or tuesday.
