Ok. I am sick and tired of resetting the CEL from P1416 for the last 6 months. I tried cleaning the check valve with carb cleaner and lubing with WD40 as Bill Curlee recommends. I removed ALL of the rubber hoses on the driver's side AND the T pipe so I could shoot this stuff directly into the end of the 3" rubber hose that's connected to the check valve behind the engine so I know for sure I filled the dang thing slam full. Even got a bloody arm from cutting it on the fuel supply line retainer clip which is right in the way - CURSE THE GM ENGINEER THAT DECIDED TO PUT A $30 PART WITH HIGH FAILURE RATE WHERE IT'S IMPOSSIBLE TO REACH IT - why the heck didn't they mount it right beside the passenger header like they did on the driver's side? Idiots! I've even considered replumbing the whole passenger side with a new check valve mounted somewhere that I can easily get to it and just abandoning the original one in place. I'm so fed up with fighting this thing, that I'm finally willing to muster the nerve to pull the intake manifold. I've done alot of mods to my car, but never messed with the engine very much. I've got the '02 service manual but it sure leaves alot to be desired. I hate to show how ignorant I am, but I need some help and I know after a couple of years on this forum that this is where I can find it - so please offer help if you can - people who just want to laugh at how naive I am can move on to the next post.

1) Service manual says to drain the coolant first. Where is the drain **** (no photo in manual)? I know it should be on the bottom of the radiator but maybe I just can't see it.

2) Fuel pressure relief procedure: manual says to connect the fuel pressure gauge (dealer tool I dont have) to the fuel pressure connector. The picture looks like the fuel pressure connector is a Tee that points vertically, but looking at the car I think it's just a Shraeder valve mounted on the end of the driver's side fuel rail. Am I correct? Can I just put a can under the end of this and depress the valve to relieve the pressure (like letting air out of a tire)?

3) I obviously don't own the Metal Fuel Line Quick Connect Release tool that the service manual tells you to use. Is there an AutoZone version of it or is there a Shade Tree Mechanic trick to get those connectors apart?

4) Are all the EVAP tube connectors the plastic ones that the manual says you can just squeeze with your fingers to disconnect?

5) Fuel injector electrical connectors: LS1HOWTO says to lift up on the shiny metal clip on the bottom of the connector. Lift UP? or do they slide out perpendicular to the axis of the connector (don't want to break it)?

6) How do you get the harness clips off the fuel rail without breaking them?

7) Does the PVC tube just pull out of the driver's rocker arm cover? i.e. just a friction fit with no retainer of any kind?

8) MAP sensor vacuum hose and elec connector: The picture in the manual is confusing and I'm assuming I'll be doing that by feel. Does anyone happen to have a photo showing how they're mounted on the back of the manifold?

9) Service manual warns you to always replace all the gaskets on the bottom of the intake. LS1HOWTO claims they're rubber and there's no need to replace them. Do they just push into a groove? What holds all 8 in place while you're trying to reposition the manifold? I assume they're readily available at the local stealership as a kit. How much $$$? Is it really necessary to replace them if they still feel rubbery?

10) Last step in manual is to clean the intake manifold but the procedure would have me remove the TB, injectors, and MAP sensor and replace ALL those gaskets and orings too (arrgh, more money). What solvent do I use?

11) Upon reinstallation, manual tells you to use threadlock GM P/N 12345382 or equivalent - won't just generic threadlock from Autozone be ok?

I just need to gain enough access to get to the stupid AIR check valve. I'm considering just leaving all the other parts as an assembly because I'm not having any problems with them. I am curious to see how dirty it is inside there because of all the threads I've read about the PVC issue and effectiveness of catch cans (which I don't have).

BTW, has anyone ever tried to bolt up the driver's side AIR pipe to the passenger side header? I know it's not supposed to go there, but it looks like there is plenty of room there (might have to make a slight notch in the bottom edge of the FRC similar to the driver's side). Just thinking out loud still thinking of replumbing.

Any guidance you guys can offer would be greatly appreciated.

 

I answered as many as i could right off the top of my head.....i hope it helps

 

I just did this for the Knock Sensors this week. Piece of cake. Got the fuel connector tool set (6 pieces for many different cars) for $10 at the local autoparts store, the Intake gasket set was $12. The Evap tubes come out with a squeeze like it says. I used a dab of gasket dope to hold each port gasket in place (just a little bit to keep it in place).

It's a STUPID design but it is what it is. Just disconnect all the hoses, no need to drain any coolant. Disconnect the injectors and the PCV tube. Get all the hoses and wires out of the way, unbolt the manifold, ease it forward enough to disconnect the Knock sensor harness, the MAP harness and a vacuum line. Lift off the intake.

 

Thanks for the help guys. I guess if you've done this before it's a no brainer. But for a first timer, I'm a little nervous. I totally rebuilt my 66 Mustang's 289 25 years ago, but you could stand in the engine bay with the engine and identify every part easily. This C5 has so many computers and wires all crammed into the minimum space, I can't identify half the stuff under the hood. Just don't want to cause more damage than I'm trying to fix.

 

STEP1
a) The three green circles in the following picture indicate two electrical plugs and one hose that need to be disconnected from the throttle body.
b) The red circles indicate the two screws that need to be opened up to remove the airbridge.


STEP2
a) The two green circles indicate a pin type rivet that can be removed by popping the top pin of the rivet with a flathead screwdriver. This will allow the airbridge to be completely removed.
b) The red circle indicates an electrical plug that should be disconnected also.

STEP3
a) Just a pic of the open throttle body, and another view of the hoses and plugs that need to be removed (green circles). Disconnect them if you haven't already.
b) The green ARROW points to the coolant hose that passes to the throttle body. This needs to be disconnected. Take a pair of pliers to the clamp on the hose that keeps it connected to the throttle body.

STEP4
a) Disconnect both plugs circled in green. The one on the right is easily removed by pressing down on the white ring and pulling the plug out.
b) The yellow arrow is a hose that *WAS* attached to the airbridge. Hopefully you've disconnected that from the airbridge already.
c) The red arrow indicates a hose that is attached to the bottom of the throttle body. This one is a b1tch to disconnect because of positioning as well as corrosion. Remove the clamp w/ pliers and yank hard, it will eventually come off.

STEP5
a) Passenger side (right side) fuel injectors (red circles). Disconnect all 4 of these by pressing the metal spring and pull the injectors out.

STEP6
a) Driver's side (left side) fuel injectors (red circles). As seen in the picture, all 4 need to be disconnected.
b) The items circled in green ***SHOULD NOT*** be disconnected. These are areas that I accidentally disconnected while going through blindly. They belong to the "EVAP Purge Vacuum Switch".

STEP7
a) The hoses circled in green are the braided fuel lines. Corvettes Prior to 1999 have 2 lines. Those built in 2000 +have only 1 line ! You have to use a GM fuel line removal tool (as seen in the picture pointed by the RED ARROW).
b) This step is *NOT NECESSARY*, however, I felt it makes it easier. When the fuel lines are disconnected, you will have a small amount of fuel spill so have a rag handy to catch it.

STEP8
a) This picture shows what the two fuel lines (green circles) look like with the hoses disconnected (red circles). Corvettes Prior to 1999 have 2 lines. Those built in 2000 +have only 1 line


STEP9
a) The 8 circled green bolts need to be removed with an 8mm socket wrench.
b) The two green arrows point to two hidden bolts that also need to be opened up (also 8mm), but using a standard wrench instead of a socket wrench. If you use a socket wrench, it will get stuck when you've opened the bolts up. These bolts cannot be lifted out of the intake at this time. Refer to the next step.


STEP10
a) The two green arrows point to those two hidden bolts. Once they've been opened up, you need to lift them up about 2 inches to give you enough clearance to pull on the intake. I used tape (as seen in the pics) to keep the bolts lifted, and free up my hands so that I could pull the intake.




STEP11
a) With the two bolts taped (lifted clearance), you should just pull the intake up a bit and pull it towards the front of the vette. Don't pull it all the way out because there is still a hose and map sensor plugs attached in the back. The pic shows what the intake will look like once you've pulled it forward a little bit.


STEP12
a) This picture was taken sideways to get a better view of the hose and plug that you have to disconnect. Both are circled in green.
b) After these two things have been disconnected, you can fully take out the entire intake with the throttle body attached.


STEP13
a) Here is a pic of the engine without the intake & throttle body. And opening the clearance to what you've been waiting for. The Oil Pressure Sensor is indicated by the green circle in the picture. I don't remember which socket size to use but it needs to be a deep socket. Pretty simple removal and installation, as it isn't in there extremely tight, you'll have plenty of clearance to put a socket wrench and deep socket in there. Just make sure you remove the electrical plug connector that goes to the Oil Pressure Sensor, before you try to remove it. Install the new one, and plug the electrical connector back in.
b) The item circled in red looks like a plastic straw. Just pay attention to this when you re-install the intake, there is a hose (on the back side of the intake right next to the map sensor) that it needs to reconnect to (hose is shown in the STEP14 picture). Failure to reconnect will result in issues with cabin airflow from A/C System !


STEP14
a) Here is a picture of the BACK of the removed intake, and the hose mentioned in STEP13b is circled in green. When you re-install the intake, just make sure the plastic stick (in red circle of picture on STEP13) is fitted back into this hose.
b) From here, after you've installed the new Oil Pressure Sensor, the re-installation of the intake manifold should be exactly in reverse order.


As far as 10 goes 10) Last step in manual is to clean the intake manifold but the procedure would have me remove the TB, injectors, and MAP sensor and replace ALL those gaskets and orings too (arrgh, more money). What solvent do I use?
Unless you have very high miles or Codes that indicate a problem here I would SKIP this disassembly !

 

Wow, ICUALL, that's very detailed. Thanks. I'm starting to get a warm fuzzy feeling that this is doable for a novice. Crossing my fingers. I'll pick up the items I need tomorrow.

 

 

Not trying to be a wise a$$, but if you have a service manual, and still have that many questions, you might want to take it to a shop to have the work done. May be saving yourself some heartache.
Good luck.

 

on this picture you can see the drain on the lower right corner of the radiator ( seen from engine side)

Use a 1/4 inch drive extension and ratchet

 

the tool used to disconnect the fuel line looks like this

 

Thanks for the photo.

Just tinkering under the hood and answering some of my own questions just in case anyone is following along...

5) Fuel injector electrical connectors: LS1HOWTO says to lift up on the shiny metal clip on the bottom of the connector. Lift UP? or do they slide out perpendicular to the axis of the connector (don't want to break it)? You don't lift up on the shiny metal horseshoe shaped clip, you push the bend toward the connectors which makes the legs of it flare out so they don't catch under some little tabs. Just push in until the legs flare out and while holding it there, pull the elec connector off.

6) How do you get the harness clips off the fuel rail without breaking them? It has plastic teeth that flare out once you push it through a hole in the bracket. You can get a pair of needle nose pliers right onto the teeth, squeeze them together, and pull the clip back out of the bracket.

7) Does the PVC tube just pull out of the driver's rocker arm cover? i.e. just a friction fit with no retainer of any kind? Yes, just pulls out with a tug.

 

Very good tips here from a couple folks and well explained. The only thing I might add is I would recommend you clean/wire-brush the threads of the manifold hold-down bolts in order to clean them. Use a drop or two of LocTite blue when re-installing. Believe and follow the torque spec for the manifold hold-down bolts. They are screwing directly into aluminum and these things are long and thin and EASILY over-torqued if you try to "guesstimate" the torque.

Also, it's the '97s and '98s only, that have two fuel hoses. Starting in '99, all have one hose. No biggie.

 

I have had mine on and off so many times I don't bother with the Loctite any more.

 

This connects to BOTH valve covers and the throttle body. Just pushes into the connections on the valve covers.

 

Just for information...

Since the reason I'm pulling off the intake manifold is to replace the AIR pump check valve, I need new check valves (decided to go ahead and replace both since they're not that expensive, and if this one has gone bad, the other is likely to in the near future). The dealerships want about $35 each for these check valves, but I got AutoZone versions for $11 each. They're not black like the OEMs but I'm going to paint them black (at least the driver's side which is right out there in the open).

STICKER SHOCK. One of the posts above says the intake manifold gaskets are $12. What he meant to say was they are $12 EACH in a kit of 8. AutoZone does not stock this item, but they can order the kit for about $22. I didn't want to wait three or four days. So I checked at two local dealerships for the OEM kit. One dealer wanted $100.06, the other wanted $80.00 for the kit!!! I will check with GMPartsHouse and GMPartsDirect and post what I find.

I did buy the metal fuel line quick connector release tools - just an assorment of various diameter plastic sleeves to push into the connector to disconnect it - less than $5. These are so small they will be easy to misplace. I also bought the blue locktight thread sealant for about $3.

Now I realize I don't have a torque wrench that goes down to low enough values to torque the intake bolts holding on this nylon manifold (which requires such a low torque they give the values in INCH POUNDS) and AutoZone only had three torque wrenches - two also too large and the other was the type that bends and you look at the pointer on a scale, but it was also designed for about 150 FOOT POUNDS. The first tick mark was probably too much for the intake manifold bolts and you could just about move it to that tick mark by barely touching it. I'll keep looking...

 

Great detailed information... I hope I never have to use it though.
If you haven't already, you should include this in the sticky at the top of the C5 tech forum for future reference.

 

GMPartsDirect - $58.90 (shipping included)
GMPartsHouse - $66.51 (shipping included)

Since I'm not having a problem with anything related to the intake manifold, I guess I'm going to go AGAINST the dictates of the service manual and NOT replace the gaskets. They are rubber and the intake is not torqued down that hard. I'm hoping they will all still look good and have good flexibility when I get the manifold off. I'll let you know.

 

Re-use them, a lot of people do it all the time.

those oil pressure senders...

 

Now I'm stuck again. Need help. Trying to removing the EVAP purge tubes, the service manual simply says to "disconnect to tube". How do you get the connector to disconnect? It's a black plastic housing with a cream colored tab sticking out through a slot on top and another from the bottom. The section on PLASTIC quick connects says that you should be able to just squeeze some tabs by hand (no tools) to get the connectors apart. Are the EVAP connectors the same type or are they talking about totally different connectors? I tried to squeeze the tabs on the EVAP connectors with my pliers but I'm afraid I'm going to break it. Please help.

 

Press on the tab and pull back-easy!!