1996 K2500 7.4 454 Intake Manifold Gasket replacement and a few other questions...

[sbdsr]

Hello all I'm new to the group and have owned this truck for about a year and have been chasing water gremlins on it during the whole time...it's a 1996 K2500 Suburban with a 7.4L 454 Engine....

My first question...are there andygood manuals my understanding from the is that the Chiltons and Haynes manuals are not very good for this truck... are there any better sources for repair information for these trucks?


Also can anyone tell me what these parts are...I can't seem to figure it out from the various schematics I have seen on GM's site...

This is towards the front of the engine on the Drivers side

You must be registered for see images attach

I'm also trying to figure out what these two parts are and how to fix them is there a rubber pipe that attaches the two pipes if so what is it called...? And apparently the piece right above it has been melted so I need to know what that is as well, and would these two things have anything to do with a gutless take off or am I going to have to chase that gremlin down as well

You must be registered for see images attach

Lastly I've seen mention of a upgraded or preferred set of gaskets for a intake manifold gasket does anyone know what that is...I think it's a FelPro...

What are the best spark plugs to use for a truck like this, platinum, iridium, or just plain old plugs...?

Is there a sticky anywhere for the best parts to use for a truck like this....?

And while I have it broken down for a intake manifold gasket, what is the must thing I need to look at and replace if needed....

Thanks in advance

 

[magimerlin]

1st pic no idea, sorry

2nd pic--- that's your secondary a.i.r. line. Yes there is a connecting hose that goes there... piece above it is the egr valve.... it probably melted as the metal line that is missing the coupler is coming right from the exhaust manifold so it's getting hit with hot exhaust... that right there (both issues) cam cause a huge case of being gutless....

Is there an engine light on?? I bet there is.... get it read so you know the codes...

sent from what use to be a great country...

 

[Jrgunn5150]

1st pic no idea, sorry

2nd pic--- that's your secondary a.i.r. line. Yes there is a connecting hose that goes there... piece above it is the egr valve.... it probably melted as the metal line that is missing the coupler is coming right from the exhaust manifold so it's getting hit with hot exhaust... that right there (both issues) cam cause a huge case of being gutless....

Is there an engine light on?? I bet there is.... get it read so you know the codes...

sent from what use to be a great country...

Do you think the first pic is the coolant temp sensor, in the side of the head?

ALLdata is a good source for manuals, or you can score the factory service manuals on Ebay.

 

[sbdsr]

1st pic no idea, sorry

2nd pic--- that's your secondary a.i.r. line. Yes there is a connecting hose that goes there... piece above it is the egr valve.... it probably melted as the metal line that is missing the coupler is coming right from the exhaust manifold so it's getting hit with hot exhaust... that right there (both issues) cam cause a huge case of being gutless....

Is there an engine light on?? I bet there is.... get it read so you know the codes...

sent from what use to be a great country...

Yes the Check engine light did come on....and the thermostat gauge started spinning like a top....I bought a BAFX ODB reader and using Torgue to see if I can get codes...but the battery died, so the device didn't pick up anything... so I'm going to have to operate in the blind until I can get it running,,,thanks for taking the time

 

[sbdsr]

Do you think the first pic is the coolant temp sensor, in the side of the head?

ALLdata is a good source for manuals, or you can score the factory service manuals on Ebay.

Thanks for the manual source and would that sensor breaking make the coolant gauge spin like a top......

 

[someotherguy]

The first pic is the sender for the temperature gauge, not the coolant temperature sensor for the PCM.

Crazy to see these Vortec 7.4's with an AIR injection tube. That is totally foreign to me. I've never seen one in person to know what type of hose joins those tubes.

The upgraded intake gasket you hear about is for the small block Vortec engines, because they are notorious for failure. For some reason the big block doesn't seem to follow in that trend. Regardless, Fel-Pro is a good brand so you could go with that.

The Vortec 7.4's are known for issues with the stock injection setup. If you've been experiencing hard starting when warm (long crank times, then eventually stumbles up to an idle, possibly smoking black), it can be bad injectors or a bad fuel pressure regulator. You get to both of these with the top half of the intake removed, so if you've had any issues like that it's time to address them. There are many choices in upgraded injectors so that's a whole topic in itself. Stick to good brands for them and the fuel pressure regulator, and be sure you also put a new piece of fuel/vapor-rated vacuum line to the fuel pressure regulator as it gets cracked/brittle with age and you can't get to it again once everything is assembled.

Be careful with the distributor and cap, as you may already know. The distributor body is plastic and the screw bosses for the cap can crack and even break off easily. It's not the end of the world if this happens, thanks to the crossfire design you can easily loop a long zip tie around the cap and body to effectively seat the cap without any wiggle. Then again if there's any wear in the top bushing (can push rotor side to side) or in the distributor gear (knife edge, "apple core" wear, etc.) then just go ahead and buy a new one.

Distributor removal/reinstall on a Vortec is a little trickier than previous designs. Mark the distributor body AND rotor positions very clearly and do your best to re-install exactly the same. You'll still need to time it with a scanner that can read the cam retard angle, and get it to within +/- 2 degrees of zero while holding RPM's to at least 1,000 for a good reading. You cannot and will not time this engine with a timing light.

Richard

 

[Christian Steffen]

That's definitely the coolant temp sensor for the dash gauge, there is a separate one in the intake manifold for the ecm though. So if you hook up your torque app you can read the coolant temp.

 

[83GMCK2500]

Most've it's been answered. Coolant temp sensor in the head, the melted black cylinder is the solenoid on the EGR valve, the right hand tube is the one that leads down to the manifold (if I remember correctly) and the bulge you have pictured is a check valve (with engine running there should be no exhaust gases coming out, if that valve failed it could've caused the melty melty, normally connected with a rubber hose to the tube on the left). Unless you need to meet emissions requirements you can remove all of those air injection lines and plug the manifolds.

Factory GM Service Manuals exist, I think it's a 2 volume set for 1996, they come up on ebay occasionally and are totally worth it.

Delco Platinum (gapped to .060, double check emissions sticker underhood) plugs and tune up parts to answer your other question. Don't bother with iridium, double, triple, +4, split, all gimmicks. In stock form Vortec engines love OEM parts. The only exception is the GARBAGE OEM fuel injectors on the 454, for that look into the Blue Knight injector set from FiveOMotorsports, the sell a kit specifically for these engines.

 

[83GMCK2500]

Hahahaha, I just noticed in your first pic: stuck on top of the spark plug wire retainer is what looks like one half of the hose that should connect those air injection lines together.

EDIT: With the other half down between the plug wire shield and manifold itself.

 

[sbdsr]

Hahahaha, I just noticed in your first pic: stuck on top of the spark plug wire retainer is what looks like one half of the hose that should connect those air injection lines together.

EDIT: With the other half down between the plug wire shield and manifold itself.

LOL...I'll be damned...you have Eagle vision....I never noticed.... the piece is brittle and doesn't have any markings...I'm wondering if this is just more cut off heater hose, like what's been used in the rest of the radiator system...I can't find anything about it on line....

You must be registered for see images attach