What else to do when removing intake?
Thread Starter
Instructor
Joined: Apr 2019
Posts: 162
Likes: 55
From: Raleigh, NC
What else to do when removing intake?
I'm going to replace cam sensor o-ring and oil pressure sender and figured I'd ask if I should do anything else while intake is off. I searched and someone said, "do the knock sensors while intake is off". Do what to them? Car has 52K miles. Would you replace all intake gaskets? I know they are "reusable" but they are also 20 years old.
Race Director
Joined: Oct 2004
Posts: 12,860
Likes: 4,661
I'm going to replace cam sensor o-ring and oil pressure sender and figured I'd ask if I should do anything else while intake is off. I searched and someone said, "do the knock sensors while intake is off". Do what to them? Car has 52K miles. Would you replace all intake gaskets? I know they are "reusable" but they are also 20 years old.
TIP!!!!
Some guys use clothes pins to hold some of the intake manifold bolts up so they don't get caught on other things as you pull/lift the intake forward to remove, and push/lift it back on reinstall. Once you remove the intake, you'll wonder why anyone ever bored a hole thru their cowl to access the oil sender!! I'd also replace all 8 intake port O-rings on the manifold. BTW, speaking of oil sender, I'd recommend buying an aftermarket sender. The OEM senders arent that great. Make sure you find the torque value for the oil sender, and torque it to that correct value, with a torque wrench. Same for the intake bolts, which are 106 lbs/inch, IIRC.......
Melting Slicks
Joined: Oct 2002
Posts: 2,515
Likes: 441
From: Arizona
I’d replace the valley cover gasket, valve cover gaskets, intake gasket, and any pcv hoses that are known to get so hot they become brittle. I’d also consider sending out your injectors for inspection and cleaning.
Be careful with the vacuum line on the back of the intake.
Be careful with the vacuum line on the back of the intake.
Thread Starter
Instructor
Joined: Apr 2019
Posts: 162
Likes: 55
From: Raleigh, NC
There's never been a V8 intake easier to remove than the LS engines!! If I were you, I'd leave the KR sensors alone if theyre working. Do your cam sensor O-ring and sender. As easy as the intake is to R&R, it's not that big of deal if you have to go back in to replace the KR sensors in a year, or two, or three.
TIP!!!!
Some guys use clothes pins to hold some of the intake manifold bolts up so they don't get caught on other things as you pull/lift the intake forward to remove, and push/lift it back on reinstall. Once you remove the intake, you'll wonder why anyone ever bored a hole thru their cowl to access the oil sender!! I'd also replace all 8 intake port O-rings on the manifold. BTW, speaking of oil sender, I'd recommend buying an aftermarket sender. The OEM senders arent that great. Make sure you find the torque value for the oil sender, and torque it to that correct value, with a torque wrench. Same for the intake bolts, which are 106 lbs/inch, IIRC.......
TIP!!!!
Some guys use clothes pins to hold some of the intake manifold bolts up so they don't get caught on other things as you pull/lift the intake forward to remove, and push/lift it back on reinstall. Once you remove the intake, you'll wonder why anyone ever bored a hole thru their cowl to access the oil sender!! I'd also replace all 8 intake port O-rings on the manifold. BTW, speaking of oil sender, I'd recommend buying an aftermarket sender. The OEM senders arent that great. Make sure you find the torque value for the oil sender, and torque it to that correct value, with a torque wrench. Same for the intake bolts, which are 106 lbs/inch, IIRC.......
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
1997- 2000 LS 1 engines had coolant air bleed ports (sometimes called steam ports) on both front and rear of the heads. For whatever reason, GM eliminated the rear port lines on 2001 forward, although the ports are still in the heads, just not connected. There are tales that assign the cause of # 7 cylinder failure on track to the lack of the rear head coolant air bleed lines on 2001 and later cars.
Many of us who run our 2001 and later C5s on track have reconnected the rear head ports while the intake is off to eliminate that possibility. Run 1/4" hose around the passenger side valve cover to connect.
Also an opportunity to install insulation between the intake manifold bottom and valley to reduce heat transfer into the intake manifold and incoming fuel/air charge.
Many of us who run our 2001 and later C5s on track have reconnected the rear head ports while the intake is off to eliminate that possibility. Run 1/4" hose around the passenger side valve cover to connect.
Also an opportunity to install insulation between the intake manifold bottom and valley to reduce heat transfer into the intake manifold and incoming fuel/air charge.
Thread Starter
Instructor
Joined: Apr 2019
Posts: 162
Likes: 55
From: Raleigh, NC
1997- 2000 LS 1 engines had coolant air bleed ports (sometimes called steam ports) on both front and rear of the heads. For whatever reason, GM eliminated the rear port lines on 2001 forward, although the ports are still in the heads, just not connected. There are tales that assign the cause of # 7 cylinder failure on track to the lack of the rear head coolant air bleed lines on 2001 and later cars.
Many of us who run our 2001 and later C5s on track have reconnected the rear head ports while the intake is off to eliminate that possibility. Run 1/4" hose around the passenger side valve cover to connect.
Also an opportunity to install insulation between the intake manifold bottom and valley to reduce heat transfer into the intake manifold and incoming fuel/air charge.
Many of us who run our 2001 and later C5s on track have reconnected the rear head ports while the intake is off to eliminate that possibility. Run 1/4" hose around the passenger side valve cover to connect.
Also an opportunity to install insulation between the intake manifold bottom and valley to reduce heat transfer into the intake manifold and incoming fuel/air charge.
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Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
Without cutting clearance on the bottom of the manifold, the line from the rear to the front ports cannot go underneath the manifold. I used a 2001 and later front unit, cut it to add hose for flexibility and ran the connecting line from the tee on the front unit (installed at the rear ports) around the passenger side valve cover to then join with the front coolant air bleed line before it connects to the radiator.
Good time to bypass the throttle body because the front coolant air bleed line goes through the throttle body before attaching to the radiator.
Good time to bypass the throttle body because the front coolant air bleed line goes through the throttle body before attaching to the radiator.
Race Director
Joined: Oct 2004
Posts: 12,860
Likes: 4,661
Without cutting clearance on the bottom of the manifold, the line from the rear to the front ports cannot go underneath the manifold. I used a 2001 and later front unit, cut it to add hose for flexibility and ran the connecting line from the tee on the front unit (installed at the rear ports) around the passenger side valve cover to then join with the front coolant air bleed line before it connects to the radiator.
Good time to bypass the throttle body because the front coolant air bleed line goes through the throttle body before attaching to the radiator.
Good time to bypass the throttle body because the front coolant air bleed line goes through the throttle body before attaching to the radiator.
Burning Brakes
Joined: Jun 2017
Posts: 760
Likes: 242
From: All Over The Place
1997- 2000 LS 1 engines had coolant air bleed ports (sometimes called steam ports) on both front and rear of the heads. For whatever reason, GM eliminated the rear port lines on 2001 forward, although the ports are still in the heads, just not connected. There are tales that assign the cause of # 7 cylinder failure on track to the lack of the rear head coolant air bleed lines on 2001 and later cars.
Many of us who run our 2001 and later C5s on track have reconnected the rear head ports while the intake is off to eliminate that possibility. Run 1/4" hose around the passenger side valve cover to connect.
Also an opportunity to install insulation between the intake manifold bottom and valley to reduce heat transfer into the intake manifold and incoming fuel/air charge.
Many of us who run our 2001 and later C5s on track have reconnected the rear head ports while the intake is off to eliminate that possibility. Run 1/4" hose around the passenger side valve cover to connect.
Also an opportunity to install insulation between the intake manifold bottom and valley to reduce heat transfer into the intake manifold and incoming fuel/air charge.
Thanks
TC
Advanced
Joined: Feb 2022
Posts: 75
Likes: 5
Thanks very much, I’m getting ready to install a LS6 intake on my 99 and was leaning towards the plugs for the rear ports, and after reading this will definitely be doing what you just described. So my only question is i already bypassed the TB and had that line from the front connecting to the radiator. So i would just insert a T in that line to connect both the front and rear lines to the radiator?
Here is the part i was looking at, for both the front and rear ports.
https://www.zip-corvette.com/97-04-t...over-pipe.html
Found this one at summit, $17 cheaper.
https://www.summitracing.com/parts/NAL-12694769
Here is the part i was looking at, for both the front and rear ports.
https://www.zip-corvette.com/97-04-t...over-pipe.html
Found this one at summit, $17 cheaper.
https://www.summitracing.com/parts/NAL-12694769
Last edited by edmiller0119; Mar 29, 2022 at 08:12 AM.
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
Here is the intake insulation I used:
https://www.heatshieldproducts.com/i-m-shield
The coolant crossover from ZIP is the one I used, the one from Summit is different, does not have a tee. I had to cut the one I used and insert a short piece of hose with clamps to obtain the needed flexibility.
Yes. a tee in the line to the radiator that goes from the bypassed throttle body to the radiator.
https://www.heatshieldproducts.com/i-m-shield
The coolant crossover from ZIP is the one I used, the one from Summit is different, does not have a tee. I had to cut the one I used and insert a short piece of hose with clamps to obtain the needed flexibility.
Yes. a tee in the line to the radiator that goes from the bypassed throttle body to the radiator.
Pro
Joined: Jan 2016
Posts: 524
Likes: 126
From: Sandown NH
Replace the secondary AIR check valve that is bolted the the back of the driver's side head---it is right near the Oil presser sender. I would also recommend installing an oil pressure sender relocation kit
This relocates the sender to under the coil cover so if it ever fails again you will not have to pull the intake to do it.
This relocates the sender to under the coil cover so if it ever fails again you will not have to pull the intake to do it.
Safety Car
Joined: Jun 2017
Posts: 4,786
Likes: 425
From: North Georgia, USA
I usually apply a single layer of stick on "HVAC duct insulation" like FrostKing FV516 (available at Lowes or from Amazon) to the top of the valley cover.
I also apply a good primer that bonds well to plastic to the manifold itself (tape over the head mounting surfaces and the throttle body opening) and follow that up with a layer of VHT "Flame Proof" exhaust paint (because it's high in ceramic content and is a thermal barrier type paint). You can use the black paint for a "stealth" look (looks almost stock), or you can use "aluminum" and people will ask you where you got the cast aluminum LS intake from.
With both, you'll see a slight rise in long term fuel trims from cooler, denser air. It won't show on the IAT, but the fuel trims will adjust to more oxygen from cooler,denser air entering the cylinders.
Drifting
Joined: Sep 2022
Posts: 1,785
Likes: 2,033
From: In the woods
2024 C5of the Year Finalist - Unmodified
https://paceperformance.com/files/pd...rque-specs.pdf