Dreaded intake manifold leak...I think?

[454cid]

What scanner were you using? I have a knock-off tech2 that only shows the CMP offset in degrees, no decimals. I was surprised to see that. I used the DashCommand app before and it had it to the tenths; I think CarGauge Pro had the same resolution.

GM’s spec was zero plus or minus two degrees, so I guess having a 1/10th accuracy really wasn’t that critical in their eyes?

If you meant to reply to me, I have an old OTC Monitor Elite. It's to the nearest degree, like your scanner.

 

[turboedge]

The knock off Tech2 will raise the RPMs for you also, which is nice. Well at least there is a mode for it on my older 94.

 

[LVJJJ]

Beautiful. sure makes a difference when they are garaged.

 

[tinfoil_hat]

Has anyone had this done in a shop and what did it cost you? I am getting ready to do my gaskets for the second time in four years and I am not thrilled about it. Thinking of letting a pro do it this time.

 

[shorepatrol]

Around 600 bucks I think.

 

[tinfoil_hat]

Around 600 bucks I think.

Gross. I'll probably do it myself.

 

[Ehall8702]

Gross. I'll probably do it myself.

We do em all the time at my shop and it's about 4-500. Higher end if ports are all ate up, we end up dremeling the nastiness out and jb welding the grooves and sanding them flat and using top of the line felpro gaskets and no issues . It's a pita but u can do it at home in 6 or so hours with hand tools.

 

[Ben Burrage]

Nice ride.. Intake gasket is super easy. I do recommend doing spider upgrade while it's off, as the old poppets suck. You will be happy you did it. Make sure to clean surface very well before reinstalling gasket, and use the AC Delco gasket maker. Love these trucks...

 

[tinfoil_hat]

We do em all the time at my shop and it's about 4-500. Higher end if ports are all ate up, we end up dremeling the nastiness out and jb welding the grooves and sanding them flat and using top of the line felpro gaskets and no issues . It's a pita but u can do it at home in 6 or so hours with hand tools.

Got a couple questions for you if you don't mind...
I did mine just about four years ago and it has failed at the back by the firewall. What do you think I did wrong?

What do you use to seal the bolt threads?

My water pump pipe pulled right out of the intake. I glued it it back in with RTV but it eventually started leaking. Have you ever had that happen? Any ideas for a more permanant fix?

 

[east302]

Is it coolant or oil leaking at the back? Which brand and type gaskets did you use?

GM calls for a dab of RTV on the cylinder head side of the gasket...

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...and a little less than 1/4-inch wide RTV on the China walls extending 1/2-inch onto the gaskets.

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GM calls for threadlock GM P/N 12345382 on the eight intake manifold bolts. I forget what I used, but Permatex and others usually have a cross-reference table for comparable products. I don’t think that any of the bolts extend into a water passage, but a few do end up in the open lifter valley.

What broke- the quick connect or the fixed line in the intake? Not sure how you would fix the line, but a new GM intake can be had for around $400. I had to go that route since mine was cracked at the ECT sensor port, I will say that working with a brand spanking new and clean intake was pretty nice.

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