HELP! Chirp after cam install.
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Instructor
Joined: May 2018
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HELP! Chirp after cam install.
I just installed a BTR stage 3 cam with new springs and pushrods. Along with a new oil pump, new timing chain, new ls7 lifters and head gaskets. This was my first time doing anything this large. I started it and initially thought I was good to go but I have a semi concerning sound coming from the driver side. What does it sound like to you guys? And should I be worried. I'll note my header to cat right now is not fully tightened.
https://youtu.be/rBO-UmBZ_5o
https://youtu.be/rBO-UmBZ_5o
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Instructor
Joined: May 2018
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Yeah, I replaced Harmonic balancer as well. I took the serpentine belt off today, tightened the headers to the cat and ran it again to check for the sound. The sound is still there. I'm curious if if takes a little bit for things to "settle in". I haven't got the engine up to temp yet just because the sound has me a little nervous.
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Instructor
Joined: May 2018
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I grabbed a stethoscope and header gaskets(didn't replace them for whatever reason). I also rented a coolant pressure tester to check head gaskets and a borescope.
So far I've checked the coolant system, very little leakage over an hour. I'll pull plugs and do it again tomorrow, hoping to rule out any head gasket leak. Also when I pull plugs I'll stick scope in there and have a peak. Next I'll pull valley cover and again take a look at everything with bore scope. If all is well I'll throw it back together, slap the gaskets on it, torque them down and send it. I'm probably being overly sensitive. I should really get a base tune in there to rule out anything of that nature. Off idle it doesn't seem to have any noise, only when it's at it's rough untuned idle.
So far I've checked the coolant system, very little leakage over an hour. I'll pull plugs and do it again tomorrow, hoping to rule out any head gasket leak. Also when I pull plugs I'll stick scope in there and have a peak. Next I'll pull valley cover and again take a look at everything with bore scope. If all is well I'll throw it back together, slap the gaskets on it, torque them down and send it. I'm probably being overly sensitive. I should really get a base tune in there to rule out anything of that nature. Off idle it doesn't seem to have any noise, only when it's at it's rough untuned idle.
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Thread Starter
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Joined: May 2018
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Last night I went ahead and pressure tested without the plugs. It wasn't losing any noticeable pressure. I left it pressurized over night and this morning it was down 1.5 psi. I'm not really worried about that.
I took the valley cover off last night to take a look at visible cam/rollers. They all look pristine so I'm hoping the other 8 are in the same shape.
I took the borescope and took a look in the spark plug holes at the Pistons. No coolant or anything in there but tons of carbon build up. I'm going to attribute that to the fact that I don't have a tune.
I'm thinking it's the header gaskets, I reused old ones that I believe were original. 100k miles on them. And I may have swapped the passenger and driver side gaskets when reassembling. I didn't mark them like I should have when I took them off.
I took the valley cover off last night to take a look at visible cam/rollers. They all look pristine so I'm hoping the other 8 are in the same shape.
I took the borescope and took a look in the spark plug holes at the Pistons. No coolant or anything in there but tons of carbon build up. I'm going to attribute that to the fact that I don't have a tune.
I'm thinking it's the header gaskets, I reused old ones that I believe were original. 100k miles on them. And I may have swapped the passenger and driver side gaskets when reassembling. I didn't mark them like I should have when I took them off.
Advanced
Joined: Feb 2016
Posts: 89
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From: Phoenx, AZ
Sounds more like an exhaust/header leak to me, but the video is pretty dang short. Get new OEM header gaskets to start and new header to cat gaskets(not sure what manifolds/setup youre using) But exhaust leaks can make some very confusing noises as theyre never uniform. Btw, that doesn't sound like a belt at all.
Race Director
Joined: Jan 2014
Posts: 12,411
Likes: 4,218
From: Huskerland
2021 C6 of the Year Finalist - Modified
Check your alternator.....I have one go bad that was making a chirping noise when it went......... opps I see you took the belt off and ran it.......nevermind! 
Last edited by Huskerman; Mar 16, 2019 at 04:10 PM.
Le Mans Master
Joined: Dec 2005
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From: Southeast TX
If you want to isolate the source of the chirp, pull a spark plug wire off one at a time. The offending cylinder will be quieter if it's not firing. That's assuming you do have a header gasket not sealing. Identify the source and you may have to change just one header gasket. If the other side is quiet, there's no reason to change that gasket.
Racer
Joined: May 2014
Posts: 488
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Yeah, I replaced Harmonic balancer as well. I took the serpentine belt off today, tightened the headers to the cat and ran it again to check for the sound. The sound is still there. I'm curious if if takes a little bit for things to "settle in". I haven't got the engine up to temp yet just because the sound has me a little nervous.
Did you take the AC belt off too? A chirp is usually belt related, if we all think the same noise? I'm so over
gatorback /continental belts chirping. Some people have great results, but I am the opposite. Just listening
to my vette this morning with the gatorback on cold start, I wanted to kill it with its chirp! And yes, I checked the alignment.
Had the same results on the main blower system. Changed belt and gone no more chirpy. I live in Australia and I cannot just get
a belt tomorrow that fits! You are sooo lucky living in a country with multiple acess to belts. Hey Sammy?
Intermediate
Joined: Oct 2017
Posts: 48
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From: Iowa
following to know what you find out.
I just started mine for the first time yesterday, fresh TMS 370 block, A&A v3 t-trim, and EPP Blower cam and I swear it has exactly what you're describing from the passenger side. Sounds like a pulley chirp but definitely sounds like it's in the middle of the passenger side - from the head-ish area. Sometimes it goes away though. It was loud on first start then now when i hear it it's quieter.
I just started mine for the first time yesterday, fresh TMS 370 block, A&A v3 t-trim, and EPP Blower cam and I swear it has exactly what you're describing from the passenger side. Sounds like a pulley chirp but definitely sounds like it's in the middle of the passenger side - from the head-ish area. Sometimes it goes away though. It was loud on first start then now when i hear it it's quieter.
Thread Starter
Instructor
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So my conclusion is: it's normal. I'm pretty sure it's a mix of no tune and headers noise. I've done literally everything I can without lifting the heads or pulling the cam back out. My friends seem to think I'm crazy thinking something is wrong they all think it sounds fine. If you take a step back and not stick your head in the engine bay it'll sound like a normal car. I think I was honestly chasing a ghost.
I have poked around with a stethoscope and listened to every square inch of the engine. I've pulled the intake and inspected the visible cam lobes/lifters. Taken a look at rockers. Pressure tested the coolant system with plugs out to test head gasket integrity. All of these tests came up with nothing. Everything seems to be in good working order.
What I have done, which also gave me a huge bit of relief, was browsed youtube and took a good listen to all the non-tuned first start videos of ls engines. That sound seems to be prominent in almost every video. Take a listen to those cars and get back to me. Tell me your thoughts. I have more videos I can upload if anyone is interested. I'm getting it tuned next week.
I have poked around with a stethoscope and listened to every square inch of the engine. I've pulled the intake and inspected the visible cam lobes/lifters. Taken a look at rockers. Pressure tested the coolant system with plugs out to test head gasket integrity. All of these tests came up with nothing. Everything seems to be in good working order.
What I have done, which also gave me a huge bit of relief, was browsed youtube and took a good listen to all the non-tuned first start videos of ls engines. That sound seems to be prominent in almost every video. Take a listen to those cars and get back to me. Tell me your thoughts. I have more videos I can upload if anyone is interested. I'm getting it tuned next week.