6.2 Valve Cover Gasket Replacement

[shawnjo6565]

I have a 1982 GMC K3500 6.2 and I need to know how to replace the valve cover gaskets.

[Robyn]

The 6.2/6.5 do not use gaskets.

The covers are sealed with a high temp silicone sealer (Gooooo in a tube) :)

Procedure

Remove the intake manifold (Unhook wires, throttle cables etc)
*** NOTE***
Coolant crossover stays in place and there will be no leaks when removing manifold

Carefully clean the intake port area of old gasket and protect against dropping junk in the ports.

Cover ports with Duct tape while working on the area.

Mark each injector line PAIR with tape 1-3 ... 5-7 2-4... 6-8
Label them

Make a carewful map of where they connect to the IP and in what order.

Remove the small sheet metal screws holding the line clamps to the Valve covers.

Remove the nuts the hold the line clamps at the manifold bolts (Usually when you remove the intake.

Loosen the injector lines from the injectors (Cover the injector fitting to keep out junk)

Loosen the line fittings at the IP *** A 3/8 drive crow foot works well for removing the injector lines at the IP ***

Cover the Fittings of the IP with a clean shop towel

***Before removing lines use a shop vac a clean the valley area of debris ***

With the lines off you can carefully unbolt and remove the Valve covers.

Use a thin sharp putty knife to slide in between the head and cover to help cut the silicone goop.

DO NOT GET ROUGH WITH THE COVERS AS THEY ARE THIN AND CAN BE TWEAKED EASILY

Clean all the goop off the cover sealer area and then lay the cover on a flat steel surface and tap down any spots where the bolt area has been distorted.

The covers need to be very very clean in the area where the goop goes.

Clean off the head area where the cover fits.

Once cleaned of old goop, wipe the area well with a rag soaked in BRAKEKLEEN to remove all oil traces

THESE AREAS MUST BE CLEAN, OIL FREE AND DRY.

Apply high temp black silicone goop to the seal area of the cover (1/4 inch thick and be sure to cover the entire area that contacts the head flange.

Carefully sit the cover on he head and install the bolts.

Lightly snug the bolt (LIGHTLY)

Let the goop cure over night and then snug the bolts on to full torque.
(Snug with a short wrench)
Do not over tighten

Reattach the lines and the parts you removed.

First start is a bit tough.

Remove glow plugs and spin engine until fuel mist appears.

Replace plugs and start normally

*** This maneuver makes getting the air purged from the injector lines far easier on the starter, batteries and your patience ***


DO NOT BE TEMPTED BY THE DARK SIDE

Do not bend the injector lines to make the job quicker :):)
Do not use gaskets,... they will leak :(


Good luck

[Dvldog8793]

Howdy
IMHO....the best "goop" on the market BY FAR, is a product called "The Right Stuff", it works great! just follow the directions as it is different than standard "goop"
Good Luck!

[Robyn]

X2
Right stuff is great.
Little more $$$ but great stuff.

[shawnjo6565]

I am at the final on this and need to know what the torque specification and tightening sequence is.

[AugustDiesel]

Anyone know the answer to the question above? I will be doing this over the long weekend and this last bit of info would be helpful. Thanks in advance.

Andy

[sctrailrider]

Well if you are using "the right stuff" snug would be the answer.. you want it to cure well and not squeeze it out..

[Robyn]

What I have done in the past with great results..

Clean all surfaces really good (no oil allowed)
Make sure the VC flange is flat and straight (no bumps around bolt holes)

Squirt a good bead of HIGH TEMP SILICONE into the VC flange.
Place VC on head and install all the bolts and then barely snug them up (Just so the silicone mushes a bit)

Let the silicone set up over night and then SNUG THE BOLTS WITH A SHORT WRENCH (1/4 DRIVE RATCHET)

You will get the best and most secure (leak free) job

If you are worried about the bolts loosening up....use a touch of BLUE LOCTITE on the threads after the goop has set up (Remove the bolts one at a time and add the LT )

Too tight and the VC warps.

Gaskets are a guaranteed leak

[AugustDiesel]

Thanks guys. This is really helpful stuff. Hope to get this done today.

Andy

[AugustDiesel]

This is as far as I got yesterday:

4149

4150

Have the Right Stuff on the bench ready to go, will pull the valve covers off this afternoon as soon as I get off work. If I’m reading the instructions correctly, the Right Stuff only takes 5 minutes to cure, is that correct? Not that I will be cranking the truck up tonight anyways, as there is other work to do. But if that cure time is correct then that seems to remove the overnight step and I can go ahead and put the engine top back together.

Either way, thanks for the step by step tutorial Robyn. I have followed it to the letter so far and have not had any issues.

[Robyn]

Good to hear...:):)

[DmaxMaverick]

This is as far as I got yesterday: Have the Right Stuff on the bench ready to go, will pull the valve covers off this afternoon as soon as I get off work. If I’m reading the instructions correctly, the Right Stuff only takes 5 minutes to cure, is that correct? Not that I will be cranking the truck up tonight anyways, as there is other work to do. But if that cure time is correct then that seems to remove the overnight step and I can go ahead and put the engine top back together.

Either way, thanks for the step by step tutorial Robyn. I have followed it to the letter so far and have not had any issues.

Not sure where you read/heard that. It cures like any other RTV (which is what it is, only a better version). A couple hours to set, and a day, more or less, to cure. Don't skip the overnight step. If you tighten it down too early, it will squish out. In some applications like with flat surface gaskets and low pressure, it can be placed into service sooner. But not in applications like the VC. Crankcase impulses will blow it out.

[AugustDiesel]

Not sure where you read/heard that. It cures like any other RTV (which is what it is, only a better version). A couple hours to set, and a day, more or less, to cure. Don't skip the overnight step. If you tighten it down too early, it will squish out. In some applications like with flat surface gaskets and low pressure, it can be placed into service sooner. But not in applications like the VC. Crankcase impulses will blow it out.

Thanks for the heads up. To answer your question: it’s on the back of the can. HOWEVER, I am following the procedures as you and Robyn have outlined, REGARDLESS of what the can says. Fortunately I did not rush into this and due to time constraints have not been able to get the valve covers back on this week, but should be able to get it done this upcoming week. I plan to do as directed: apply the Right Stuff, and reinstall VC, barely snugged, next day remove VC bolts to add blue loctite and reinstall and torque.

[More Power]

...I plan to do as directed: apply the Right Stuff, and reinstall VC, barely snugged, next day remove VC bolts to add blue loctite and reinstall and torque.

A 5mm bead is sufficient. A little sealant will find its way onto the threads of the bolts - a little is actually preferred. That's enough to keep them from loosening - thread locker isn't normally needed. Just don't let more than a little sealant find its way into the bolt holes. It'll prevent the bolts from reaching full depth.

As a way of relating... The valve covers installed on our 6.5 Power Project engine were installed as outlined here. The valve cover bolts didn't loosen and there was no oil leakage for 300,000 miles. Jim