Lower manifold gasket observations

Thank you.

You -did- keep the push rods in order, didn't you?

It's the gasket itself that fails.

How often was the coolant changed?

I think Neil is pulling your leg. We (and I'm sure he) routinely do this job in under 2 hrs.

Ian

The coolant has to be "fresh". It must contain available stuff that is more electro-negative than aluminum. Otherwise the free oxygen will attack the Alum and the Alum sacrifices itself to save any iron in the engine.

Lithium -3.00 volts Potassium -2.92 Barium -2.90 Strontium -2.90 Calcium -2.87 Sodium -2.72 Magnesium -2.34 Aluminum -1.67 Manganese -1.10 Zinc -0.76 Iron -0.44 Copper +0.34 Oxygen +0.40

Yes, heeding the numerous warnings posted by folks in this group I removed the push rods one at a time and marked each one using electrical wire markers. Placed these markers at the top of each rod so I knew which end was up.

I'll examine the old gaskets a little more closely in hopes of seeing what deteriorated on them.

Don't know for certain as the vehicle was bought used. However, my strong suspicions are that it was still running on the original DexCool until about two months ago when I flushed the system and refilled it myself out of concern for it begin overdue for a recommended change.

Now I'm gett>

Ian, you gotta remember that I've had 2 heart attacks, 4 by-passes. I have 12 pins and an artificial knee in my left leg*, 5 pins in my right leg and had a broken back.

*(left leg used to have 18 pins in it before the knee swap)

IOWs, I ain't as fast as I used to was.

Good man!

Usually they are sheared apart at the silicone inserts, other times it's just that the lower manifold bolts loosen up and the gasket loses clamp.

Original coolant at that age with depleted additives would account for the pitting.

Several nitpicking type questions. Hope you don't mind. I'm kind of anal when it comes to details like these.

Having trouble finding Loctite in my area for some reason. Everyone around here has Permatex. Does anyone out there have any qualms about using the Permatex "blue" medium strength threadlocker product for the upper and lower manifold bolts?

Will the Loctite or Permatex threadlocker stand up to the motor oil the four center bolts are exposed to?

Does the lubricating effect of the threadlocker significantly affect the torque being applied to the bolts? My thinking is that the bolts could be overtightened if the threadlocker reduces the thread friction.

I could order a new set of bolts from the dealer, but I'm trying to minimize the delay already created by my steep learning curve.

Is the same kind of stuff that the factory puts on the new and replacement bolts available over the counter? If so, what is the product name?

The center bolts for the lower manifold each have a flat washer with a rubber insert. They look like they would be hard to find. Will a dab of RTV under the bolt head help ensure a good seal upon reassembly?

The Right Stuff gasket maker says it sets up in about five minutes. I am slow and deliberate on undertakings like this one. Will the fast set time be a problem for me? If so the FelPro stuff that came with the gasket set might be adequate.

I bought a 10 mm crow's foot for two of the diagonal bolts. Do you correct for the length of the crow's foot when applying torque?

Has there been any change to the recommended bolt torquing sequence or to the two stages of torquing?

Thanks for indulging me on these questions.

Anal is good, no point in having to do it over...

Go ahead, use the Permatex brand. Loctite is often used as a generic term for thread locker.

Yes.

The addition of Loctite to the bolt threads is taken into consideration when the torque value is specified. DO NOT over torque the bolts, you WILL distort the engine block and make bad things happen.

I've been reusing these bolts for years.

Hard to tell who sold it originally to GM, could just as easily be a Loctite product, a Permatex product or PermaBond (National Starch) What is important is that the thread locker meet the specs for the job. Your choice at hand certainly does.

Not a bad idea..

It won't go solid in 5 minutes, it may skin over a bit... With everything cleaned, scraped and ready to install, the 5 minutes shouldn't be a problem, apply the Right Stuff, grab manifold, set in place, then relax and start applying thread locker and loading the bolts into place. The 5 minutes is not the time you have meet to have all bolts torqued. As long as the manifold is down in place and contacting the Right Stuff, you'll be fine.

Yes. Don't have the formula off the top of my head since when I need to use a crows foot in a torque application, I use a Snap-On slide rule type calculator. Tho I must say, I haven't found the need here to use a crows foot.

Any changes from when the car was built will be included with the gaskets, follow -their- torque specifications. Go around at least twice with the final torque, some of the bolts first torqued will probably change value as the manifold is pulled down to its final position.

Glad to help.

Geeze man! I'm impressed. I've never gotten it down to 2 hours. I've never tried to get it down to that, but that's certainly humping your way through this piece of work.

Thanks a bunch Mr. Cuda. You have eased my mind immeasurably. It's reassuring and educational to discuss this job with someone who has been there and done that a number of times.

More Usenet groups should contain discussions like this one. Very educational and noone calling somebody an a*hole or worse. Quite refreshing these days....

Nice reply! I second Bishoop on his reply.

Why? We do this for a living. We do it over, and over, and over...again. The person that tackles it for the first, or second, or third time, is doing well if it took them

6-8 hrs. Especially if you are simply a hobby mechanic.

Ian

Yeah....but you probably remove the rear valve cover and loosen off the rocker arms.

Ian

In theory, you should be replacing the bolts as this is what is called for in the bulletin released by GM. I believe the reason why they call for the new bolts is that the new bolts already have the loctite applied to the threads, and GM figures that there are enough lazy techs out there that will not clean the old bolts up and re-apply new loctite. So in your case, using the old bolts would be fine.

The new style replacement bolts don't have this washer...so I don't think it will really matter. I've never used RTV in the area you mention, nor have I ever seen any leaks develop from those locations.

I use a flex socket that works for all four of the diagonal bolts.

Do the new gaskets have the two metal pellets imbedded in the gasket at either ends? If so, here is the torque spec.

Tighten

1.. Tighten the vertical lower intake manifold bolts (1) to 7N·m (62 lb in). 2.. Tighten the diagonal lower intake manifold bolts (2) to 7N·m(62 lb in). 3.. Tighten the vertical lower intake manifold bolts (1) to 13N·m(115 lb in). 4.. Tighten the diagonal lower intake manifold bolts (2) to 25N·m(18 lb ft).

Ian

My torquing sequence was very close to what you described.

Torqued ALL bolts to 62 lb-in in sequence Torqued ALL bolts to 115 lb-in in sequence Torqued diagonal bolts to 18 lb-ft in diagonal sequence

Made several intermediate checks of the center bolts to ensure they were maintaining their torque as the gasket compressed per Mr. Cuda's advice.

Did not look for any metal pellets that you reference. I assume that such a feature is present for GM replacement gaskets; however, my new gaskets are made by FelPro as recommended by a couple of esteemed gentlemen in this group.

Also made a mistake right from the get go. After setting the manifold in place the first bolt I put in was one of the diagonals on the pump/alternator end. That was a blunder. Had much trouble getting the bolt on the opposite end and side started after that. Later after the dust had settled it occurred to me that the center bolts should have gone in first and been given a 62 lb-in torquing. That should have squeezed the gasket enough to let those diagonal bolts line up correctly on both sides of the manifold. Lesson learned.

Still don't have a real good feeling about the end sealing. Not sure I used enough Right Stuff, but it did squeeze out of the joint. Due to disruptions there has been no job progress past reinstalling the lower manifold. I'm about half tempted to take the lower manifold off again and start over from scratch now that I know what I know. Would those FelPro gaskets seal properly again after they've been torqued once?

You have piqued my curiosity about the tool you use on those diagonal bolts. I can hardly get my 3/8" drive socket and swivel head on two of the bolts unless they are almost all the way in. It was my impression that a specific torque applied at an angle doesn't produce the desired torque at the bolt. That's why I used the crow's foot per the service manual's instructions. Made a correction of about 6% to account for the length of the crow's foot.