Ls3 idle and possible exhaust leak - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Sean1985 · 09-04-2016, 05:05 PM

I just finished up a ls3 525hp and a tremec swap in my 67. I probably put about 100 miles on it with no issues. Changed the oil once and it looked great.
A couple days ago I started to hear a light tick and really thought nothing of it. I got on it a little to about 4500rpm in 2nd gear and it got worse. I immediately thought it was a exhaust leak so I swapped the headers gaskets and tightened down the collectors. Still the same.

I found the Evap line was rubbing the idler pulley and it wore a hole in it. So i capped that off and the same thing. The rpm is a little spiratic. Sometimes is stays at 2000 rpm when I start up or if I rev it a little.

At this point I'm a little stumped. No check engine light and I don't have a tool to plug into. Not sure if I need the Evap. The harness does not have a plug for it. Any help would be great. Thanks.

**GMC-YA68** · 09-06-2016, 02:04 PM

Not saying this is your case, but in a previous swap I had an oil pump o-ring go bad and was causing ticking. Got worse as the oil warmed up.

Was this engine a pull out? Using the factory LS3 exhaust manifolds? It's possible they could have been cracked in the wreck.

BR3W CITY · 09-06-2016, 07:41 PM

Put a screwdriver on the valvecover and tell me if you can feel the tick through it. (older guys should understand what I mean by this).

If its valvetrain noise or lifter tick, you can usually feel the mechanical *tick*in the vibrations of the motor.

If your using a tube header (anything buy a cast manifold) which has a thin material thickness, you will hear much more noise than you would with a cast manifold. Its not actually valvetrain noise, its hearing the valve operation from the header side.

I'm not second guessing you, but are you SURE this is a new noise? 100miles isn't a ton of time to get familiar with all the noises/strains/whistles the engine and truck will make at various speeds and rpm. A hot motor will sound different than a cold one, and if there was any fresh build work, the breakin period will change the sound as well.

Sean1985 · 09-07-2016, 10:39 PM

Just a little update. Took it to gm since the motor is brand new and so far they found a loose rocker arm and broken valve spring. They're still digging into it. Pretty crazy. I followed th break in procedure perfectly. So far the dealer has been super honest.

zach_carver · 09-08-2016, 07:23 AM

Wow wouldnt of expected that.. Atleast they are figuring it out!

**66ChevyMax** · 09-08-2016, 12:34 PM

Glad you took it in and progress is being made

solidaxel · 09-08-2016, 04:02 PM

Were you using the GM warranty that came with the LS from GM?

Sean1985 · 09-08-2016, 05:29 PM

Yes it's under warranty from gm. Also just got word they replaced valve spring and rocker arm. Same thing. Replacing lifters which is what I thought was the problem. I've heard some lifter issues with the ls3.

solidaxel · 09-08-2016, 10:54 PM

Quote:

Originally Posted by Sean1985

Yes it's under warranty from gm. Also just got word they replaced valve spring and rocker arm. Same thing. Replacing lifters which is what I thought was the problem. I've heard some lifter issues with the ls3.

I guess I better fill out my warranty card and send it in!

Just paid for a LS-3 (19301326) but do not have it installed.

How long did you have the engine before you started it?

Is there a time period on these new crate engines, and does it start with delivery date?

Sean1985 · 09-08-2016, 10:59 PM

Quote:

Originally Posted by solidaxel

I guess I better fill out my warranty card and send it in!

Just paid for a LS-3 (19301326) but do not have it installed.

How long did you have the engine before you started it?

Is there a time period on these new crate engines, and does it start with delivery date?

I had for about a 6 weeks before I started it. I didn't get a warranty card. Just took my receipt with me. I ordered it from jegs. As soon as I got the motor I did a Holley oil pan and then primed the motor while it was on a stand. Then I primed it again before start up.

solidaxel · 09-08-2016, 11:07 PM

That it !
Your Chevy dealer sounds like a great outfit!!

Sean1985 · 09-21-2016, 11:16 PM

Bad lifter and this was my push rod. Took 2 weeks but everyone was super cool and did a great job

72MARIO · 09-21-2016, 11:59 PM

How do you prime a ls engine ? Glad the dealer took care of the problem nice to see a warranty actually mean somthing

Sean1985 · 09-22-2016, 09:43 AM

Quote:

Originally Posted by 72MARIO

How do you prime a ls engine ? Glad the dealer took care of the problem nice to see a warranty actually mean somthing

I primed it with a oil primer tank. You put the oil in the tank and fill it with compressed air. I took out the oil pressure sensor and bought a fitting for it. Then I took my Holley oil pan and drilled and tapped the block off port to accept a 1/8" pipe tap. Then put a gauge in it. I did a mechanical guage when it was in the garage then I hooked up my Dakota digital guage when it was in the truck.

**66ChevyMax** · 09-22-2016, 09:49 AM

You can also turn the motor over without the ECU being hooked up. I did this with my gauges hooked up, took about 5 hits with the starter before I had oil pressure.

Quote:

Originally Posted by 72MARIO

How do you prime a ls engine ? Glad the dealer took care of the problem nice to see a warranty actually mean somthing

**66ChevyMax** · 09-22-2016, 09:50 AM

That is one sad looking push rod, glad you got her fixed up.

09-04-2016, 05:05 PM	#1
Sean1985 Registered User Join Date: Dec 2013 Location: Carlsbad Posts: 133	Ls3 idle and possible exhaust leak I just finished up a ls3 525hp and a tremec swap in my 67. I probably put about 100 miles on it with no issues. Changed the oil once and it looked great. A couple days ago I started to hear a light tick and really thought nothing of it. I got on it a little to about 4500rpm in 2nd gear and it got worse. I immediately thought it was a exhaust leak so I swapped the headers gaskets and tightened down the collectors. Still the same. I found the Evap line was rubbing the idler pulley and it wore a hole in it. So i capped that off and the same thing. The rpm is a little spiratic. Sometimes is stays at 2000 rpm when I start up or if I rev it a little. At this point I'm a little stumped. No check engine light and I don't have a tool to plug into. Not sure if I need the Evap. The harness does not have a plug for it. Any help would be great. Thanks.

09-06-2016, 02:04 PM	#2
GMC-YA68 Senior Member Join Date: Mar 2004 Location: Lee's Summit, MO (KC) Posts: 742	Re: Ls3 idle and possible exhaust leak Not saying this is your case, but in a previous swap I had an oil pump o-ring go bad and was causing ticking. Got worse as the oil warmed up. Was this engine a pull out? Using the factory LS3 exhaust manifolds? It's possible they could have been cracked in the wreck. __________________ -Keegan- '72 Jimmy 4x4 - 5.3/4L65E/NP205 swap http://67-72chevytrucks.com/vboard/s...d.php?t=663780

09-06-2016, 07:41 PM	#3
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: Ls3 idle and possible exhaust leak Put a screwdriver on the valvecover and tell me if you can feel the tick through it. (older guys should understand what I mean by this). If its valvetrain noise or lifter tick, you can usually feel the mechanical tickin the vibrations of the motor. If your using a tube header (anything buy a cast manifold) which has a thin material thickness, you will hear much more noise than you would with a cast manifold. Its not actually valvetrain noise, its hearing the valve operation from the header side. I'm not second guessing you, but are you SURE this is a new noise? 100miles isn't a ton of time to get familiar with all the noises/strains/whistles the engine and truck will make at various speeds and rpm. A hot motor will sound different than a cold one, and if there was any fresh build work, the breakin period will change the sound as well. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

09-07-2016, 10:39 PM	#4
Sean1985 Registered User Join Date: Dec 2013 Location: Carlsbad Posts: 133	Re: Ls3 idle and possible exhaust leak Just a little update. Took it to gm since the motor is brand new and so far they found a loose rocker arm and broken valve spring. They're still digging into it. Pretty crazy. I followed th break in procedure perfectly. So far the dealer has been super honest.

09-08-2016, 07:23 AM	#5
zach_carver Registered User Join Date: Aug 2014 Location: Blue Ridge,GA Posts: 508	Re: Ls3 idle and possible exhaust leak Wow wouldnt of expected that.. Atleast they are figuring it out! __________________ 1965 C10 LS2/4l70, WHITE, 5/7 DROP LINK TO SUPER SNOOPY C10 BUILD---> http://67-72chevytrucks.com/vboard/s...d.php?t=689283 1977 C10 SILVERADO HAWAIIAN BLUE, 5/5" DROP, LS6/4L80E 1976 CHEVY K5, 350/350, YUBA GOLD/SADDLE

09-08-2016, 12:34 PM	#6
66ChevyMax Senior Member Join Date: Oct 2011 Location: Wolfforth, Texas Posts: 976	Re: Ls3 idle and possible exhaust leak Glad you took it in and progress is being made __________________ Craig 1966 Chevrolet C10 - Supercharged LS3 1968 Chevrolet Camaro 1957 Chevrolet 2dr Hardtop "It makes sence if you don't think about it" Mesquite 1966 C10 - LS3 W/ Air Ride http://67-72chevytrucks.com/vboard/s...=1#post4989763

09-08-2016, 04:02 PM	#7
solidaxel Registered User Join Date: Dec 2002 Location: Cactus Patch So. Az Posts: 4,749	Re: Ls3 idle and possible exhaust leak Were you using the GM warranty that came with the LS from GM? __________________ 53 TuTone Extended Cab 350 4-Spd 3:08 (SOLD) 53 Chevy Moldy pearl green ZZ-4 4L60E 9" 3:25 55 GMC 1st Black Mll (ZZ4) ZZ6 TKO 600 5 sp 3:73 62 Solidaxle Corvette Roman Red (327 340hp 4spd 3:36) C4 & C5 suspension tube chassis LS 3 4L70E 65 Corvette Coupe 327 350hp 4spd 4:11 78 Black Silverado SWB (350/350) 5.3 & 4L60E 3:42 2000 S-Type 3.0 (wife cruiser) 2003 GMC SCSB 5.3 4L60E 3:42

09-08-2016, 05:29 PM	#8
Sean1985 Registered User Join Date: Dec 2013 Location: Carlsbad Posts: 133	Re: Ls3 idle and possible exhaust leak Yes it's under warranty from gm. Also just got word they replaced valve spring and rocker arm. Same thing. Replacing lifters which is what I thought was the problem. I've heard some lifter issues with the ls3.

09-08-2016, 11:07 PM	#11
solidaxel Registered User Join Date: Dec 2002 Location: Cactus Patch So. Az Posts: 4,749	Re: Ls3 idle and possible exhaust leak That it ! Your Chevy dealer sounds like a great outfit!! __________________ 53 TuTone Extended Cab 350 4-Spd 3:08 (SOLD) 53 Chevy Moldy pearl green ZZ-4 4L60E 9" 3:25 55 GMC 1st Black Mll (ZZ4) ZZ6 TKO 600 5 sp 3:73 62 Solidaxle Corvette Roman Red (327 340hp 4spd 3:36) C4 & C5 suspension tube chassis LS 3 4L70E 65 Corvette Coupe 327 350hp 4spd 4:11 78 Black Silverado SWB (350/350) 5.3 & 4L60E 3:42 2000 S-Type 3.0 (wife cruiser) 2003 GMC SCSB 5.3 4L60E 3:42

09-21-2016, 11:16 PM	#12
Sean1985 Registered User Join Date: Dec 2013 Location: Carlsbad Posts: 133	Re: Ls3 idle and possible exhaust leak Bad lifter and this was my push rod. Took 2 weeks but everyone was super cool and did a great job Attached Images

09-21-2016, 11:59 PM	#13
72MARIO Registered User Join Date: Nov 2000 Location: Huntsville Ontario Canada Posts: 4,051	Re: Ls3 idle and possible exhaust leak How do you prime a ls engine ? Glad the dealer took care of the problem nice to see a warranty actually mean somthing __________________ 1968 Suburban numbers matching all original truck now equipped with 6.0/4L80 on Accuair http://67-72chevytrucks.com/vboard/s...d.php?t=625017 1967 C/20 6.0/4L80 Roofing Truck 1990 V2500 Suburban "Plow Truck" 2005 TAHOE DD

09-22-2016, 09:50 AM	#16
66ChevyMax Senior Member Join Date: Oct 2011 Location: Wolfforth, Texas Posts: 976	Re: Ls3 idle and possible exhaust leak That is one sad looking push rod, glad you got her fixed up. __________________ Craig 1966 Chevrolet C10 - Supercharged LS3 1968 Chevrolet Camaro 1957 Chevrolet 2dr Hardtop "It makes sence if you don't think about it" Mesquite 1966 C10 - LS3 W/ Air Ride http://67-72chevytrucks.com/vboard/s...=1#post4989763



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