Thicker intake gaskets
Thread Starter
Staging Lane
Joined: Jul 2016
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Thicker intake gaskets I’ve had a code pop up off and on and it refers me to intake gaskets. I’ve put new ones on well before getting this code. My heads had been shaved but not sure how much. I see they sell different thickness intake gaskets for the LS. Should I try a set of these and can I go to thick?
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
If you shaved the heads, theoretically you would need THINNER ones. However, the LS doesn't use gaskets on the intake, it uses O-RINGS. You would know this if you have EVER seen one disassembled. Someone's blowing smoke on this one.
Thread Starter
Staging Lane
Joined: Jul 2016
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https://ls1tech.com/forums/attachmen...1&d=1512168062
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
I was only going by what you said above. So the rudeness can stop RIGHT NOW!
Yes they sell thicker ones, but for another application. If you have the right ones for your app, one might be leaking. Did you remove the intake before this issue?
And I tapped the link. It comes back invalid. Try again.
Yes they sell thicker ones, but for another application. If you have the right ones for your app, one might be leaking. Did you remove the intake before this issue?
And I tapped the link. It comes back invalid. Try again.
Thread Starter
Staging Lane
Joined: Jul 2016
Posts: 61
Likes: 0
I was only going by what you said above. So the rudeness can stop RIGHT NOW!
Yes they sell thicker ones, but for another application. If you have the right ones for your app, one might be leaking. Did you remove the intake before this issue?
And I tapped the link. It comes back invalid. Try again.
Yes they sell thicker ones, but for another application. If you have the right ones for your app, one might be leaking. Did you remove the intake before this issue?
And I tapped the link. It comes back invalid. Try again.
Thread Starter
Staging Lane
Joined: Jul 2016
Posts: 61
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It’s just a LS1 with cam, headers and LS6 intake. This is in my 64 nova so no emissions stuff. My map sensor was a source of vacuum leak but fixed that with a new seal. Cleaned LS3 style maf sensor. 02 sensors are good. Replaced intake o-rings but still pops up time to time,code. Tuner noticed the 02 sensors pouring fuel in at idle and part throttle. That’s when we found map leak.
Last edited by Bmac89; Dec 1, 2017 at 08:32 PM.
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TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
Alright, how do they say to use the different thicknesses? There are different manifolds available aftermarket for the LS1 and other LS engines, and some of these O-rings might be for them. There is no reason to vary thicknesses for a single application. Are you experiencing vacuum leaks right now? And I did NOT say Fel-pro was wrong, nor even imply it.
The message I get on the link comes from LS1Tech, so it's not your fault either.
Which code # pops up? That will help others here who might help you.
The message I get on the link comes from LS1Tech, so it's not your fault either.
Which code # pops up? That will help others here who might help you.
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TECH Junkie
Joined: Nov 2013
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From: White Bear, Mn
I would make sure the intake is seated all the way. Even if the heads were milled .030" - .040" the intake should still seal.
Is the bottom of the Ls6 intake ground down?
Is the bottom of the intake slightly hitting the knock sensors or knock sensor wires.....
Is the bottom of the Ls6 intake ground down?
Is the bottom of the intake slightly hitting the knock sensors or knock sensor wires.....
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
If that is correct, the causes listed are:
-Faulty heated front O2 sensor
-Ignition misfiring
-Faulty fuel injectors
-Exhaust gas leaks
-Incorrect fuel pressure
-Faulty MAF sensor
The code is activated by too rich a mixture
NONE of this is related to intake sealing, by the way
-Faulty heated front O2 sensor
-Ignition misfiring
-Faulty fuel injectors
-Exhaust gas leaks
-Incorrect fuel pressure
-Faulty MAF sensor
The code is activated by too rich a mixture
NONE of this is related to intake sealing, by the way
Thread Starter
Staging Lane
Joined: Jul 2016
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Just got home and hooked my scanning tool up and it shows PO174( my bad)system too lean.
https://ls1tech.com/forums/attachmen...1&d=1512181668
https://ls1tech.com/forums/attachmen...1&d=1512181668
Thread Starter
Staging Lane
Joined: Jul 2016
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Thread Starter
Staging Lane
Joined: Jul 2016
Posts: 61
Likes: 0
The intake isn’t ground down or anything. When I swapped intakes and put the new o-rings on I can’t say for sure it wasnt hitting anything. Pretty much just set it in place and torqued it down. Is this a common issue with intakes hitting that stuff?
TECH Junkie
Joined: Nov 2013
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From: White Bear, Mn
Another place to check is on the passenger side there is a tube that is wrapped in foam that is part of the pcv system. It runs right below the fuel rail.
There is a section in there were it connects to another section that's a slip fit that sometimes disconnects when rejoicing the intake causing a lean code.
There is a section in there were it connects to another section that's a slip fit that sometimes disconnects when rejoicing the intake causing a lean code.
TECH Junkie
Joined: Nov 2013
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From: White Bear, Mn
Yes, the bottom fins on the bottom of the Ls6 intake absolutely have to be ground down otherwise the steam pipes and some times the knock sensors will prevent it from seating all the way.
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
Just got home and hooked my scanning tool up and it shows PO174( my bad)system too lean.
https://ls1tech.com/forums/attachmen...1&d=1512181668
https://ls1tech.com/forums/attachmen...1&d=1512181668
The causes are:
-Dirty or faulty MAF
-Vacuum leak (manifold O-ring??)
-Fuel system problem (rail, injectors, pump, regulator)
So now that we have the correct code, you know what could be it. And the manifold seal IS one possibility! Try a test where you spray WD40 around the ports to see if it does anything. Any leak will become evident.