Possible bottom end noise after heads cam
05-02-2017, 08:13 PM
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Possible bottom end noise after heads cam I believe this is my first post here. If not, it was years ago. Anyways.. I just did a h/c/i on my c5. Stock bottom with 98k. PRC 227cc heads. TSP cam (231/238, 629/629.. or something close to those specs, don't remember exacts off the top of my head). Ls6 intake. Untuned as of now.
I tore the car down, it sat for about 3 months (covered by garage) then finally got around to getting it back together this weekend. It started right up. I ran it thru 3 heat cycles. Changed the oil (oil appeared clean). New oil on dipstick appears clean.
Here is the issue - I have some valvetrain noise (which I knew to be expected).. I also have I believe to be a separate noise. I thought it was an exhaust leak..but after putting a stethoscope on the oil pan, that's where the noise is predominant and there's not much sign of an exhaust leak. There's no codes for knock. There's a code in history of p0300 which is a misfire. Not sure if this is current though or from past..and possibly has nothing to do with this issue. Could a too short push rod cause this noise to radiant from the bottom? I ordered the push rods TSP recommended, but I also checked the length on cylinder 2 for intake and exhaust. One may have been half a turn off when using the comp cam length checker (example:13 turns had a very slight tap, but 13.5 turns did not when checking) I don't feel this would cause a massive difference to where id be hearing this noise. I'll be posting a video tomorrow, but any opinions before then would be great! Thanks!
I tore the car down, it sat for about 3 months (covered by garage) then finally got around to getting it back together this weekend. It started right up. I ran it thru 3 heat cycles. Changed the oil (oil appeared clean). New oil on dipstick appears clean.
Here is the issue - I have some valvetrain noise (which I knew to be expected).. I also have I believe to be a separate noise. I thought it was an exhaust leak..but after putting a stethoscope on the oil pan, that's where the noise is predominant and there's not much sign of an exhaust leak. There's no codes for knock. There's a code in history of p0300 which is a misfire. Not sure if this is current though or from past..and possibly has nothing to do with this issue. Could a too short push rod cause this noise to radiant from the bottom? I ordered the push rods TSP recommended, but I also checked the length on cylinder 2 for intake and exhaust. One may have been half a turn off when using the comp cam length checker (example:13 turns had a very slight tap, but 13.5 turns did not when checking) I don't feel this would cause a massive difference to where id be hearing this noise. I'll be posting a video tomorrow, but any opinions before then would be great! Thanks!
05-03-2017, 07:31 AM
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https://youtu.be/q1qgPVBsVzs
Here is the video. At 1:08 you can hear what I'm talking about, as well as the beginning from in car. You can also hear some of the valve train noise mid video.
This is probably going to get me flamed- but I did not check PTV clearances. Honestly, when I bought everything the guy I was working with at TSP said I had nothing to worry about. In my ignorance, I forgot all about doing it I'm assuming because of his word.
The exact cam specs are 231/237 .629/.629 115lsa with 112 intake centerline. I'm using ls9 head gaskets. As I stated previously, PRC 227cc heads.
I believe the pushrods could POSSIBLY be .025 off.
Thoughts??
Here is the video. At 1:08 you can hear what I'm talking about, as well as the beginning from in car. You can also hear some of the valve train noise mid video.
This is probably going to get me flamed- but I did not check PTV clearances. Honestly, when I bought everything the guy I was working with at TSP said I had nothing to worry about. In my ignorance, I forgot all about doing it I'm assuming because of his word.
The exact cam specs are 231/237 .629/.629 115lsa with 112 intake centerline. I'm using ls9 head gaskets. As I stated previously, PRC 227cc heads.
I believe the pushrods could POSSIBLY be .025 off.
Thoughts??
05-03-2017, 03:56 PM
#4
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Give it a little more time...
05-03-2017, 05:35 PM
#6
That's too much noise, something is way off. 1st thing is check for tiny air bubbles in the oil. Also how did you determine the push rod length? From the sounds of it I'd say there is air in the oil and most likely the oring is damaged.
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05-03-2017, 05:59 PM
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I used the push rod length checker from comp. Using this information: Take the # of turns and multiply that number by 0.050” Add 6.80”. (This is the length of the checker) Now add lifter preload* This is your pushrod length
05-03-2017, 06:01 PM
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There are tiny air bubbles in the oil on the dipstick. Are you talking about the pick up tube o ring? My guage is showing good oil pressure..
05-03-2017, 06:13 PM
#12
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Correct on the O-ring
05-03-2017, 06:16 PM
#13
Pressure has nothing to do with it. You could have 100psi and if there is air in the oil the engine is going to be noisy. The oring would need to be badly damaged to cause low oil pressure. Air is in the oil because the oring is not sealing well enough to keep it out. That means just a small AIR LEAK, the oring SEALS OUT AIR. I know everyone thinks it seals oil in........that's another lesson for another day.
If your oil is full of air bubbles the oring is letting in a small amount of air. Did you replace the oring?
If your oil is full of air bubbles the oring is letting in a small amount of air. Did you replace the oring?
05-03-2017, 06:22 PM
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Pressure has nothing to do with it. You could have 100psi and if there is air in the oil the engine is going to be noisy. The oring would need to be badly damaged to cause low oil pressure. Air is in the oil because the oring is not sealing well enough to keep it out. That means just a small AIR LEAK, the oring SEALS OUT AIR. I know everyone thinks it seals oil in........that's another lesson for another day.
If your oil is full of air bubbles the oring is letting in a small amount of air. Did you replace the oring?
If your oil is full of air bubbles the oring is letting in a small amount of air. Did you replace the oring?
05-03-2017, 06:27 PM
#16
Yes the engine will be fine, but until you correct the oring problem it will be noisy. You gotta go back in and this time be more careful. Probably just a tiny pinch on the oring. Be sure you have the correct oring and soak in in some thing like lucas oil treatment or STP etc. Something that will help it move into place without tearing or pinching.
1st thing is too remove it so you can see the condition and if it is the proper size.
1st thing is too remove it so you can see the condition and if it is the proper size.
05-03-2017, 06:49 PM
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Don't apologize! You've been a huge help. I don't believe I damaged it but I'll check what part of it I can. And yes I bought a ported ls6 pump from TSP. It came with 3 o rings.. I used the one that was said to be the equivalent size of factory.
