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Torque sequence & pound spec's-Intake manifold gasket repair

Intake manifold gasket repair

Torque sequence & pound spec's-Intake manifold gasket repair

Postby 2001_gmc_sierra [OP] » Nov 24 2011, 7:36am

Hey guys, I'm hoping someone can help answer my question...

I’m planning on replacing my intake manifold gasket on my 2001 GMC Sierra, 1500 ½ ton 4.8 Liter Vortec engine, as it idles really rough on a cold start-up. After it warms up it runs great, but the check engine light comes on for a few days, and then turns off. I had a mechanic look at it and he said the intake manifold gasket needed to be replaced, and the air injection check valves too. I’m planning on starting with replacing the intake manifold first though. Can someone please provide me with the tightening sequence, and the 2-step pound torque requirements, as I’m hoping to do this project this holiday week end. I've been looking on other web-sites but have been unable to find anything specific to my type engine, so I joined this forum with the hopes that someone can help. Thank you in advance, and Happy Thanksgiving!
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Related Topics  Intake/Exhaust Valve Sequence   98 5.7 no start after replacing intake gasket.   Oil on intake manifold   Aluminum intake manifold?   K&N Cold Air Intake   K&N Cold Air Intake   New K&N 77 Series Cold Air intake OTW !!!!   Cold Air Intake & Gas Mileage   K&N 63 Series Cold Air Intake Problems   Head gasket   Broken Exhaust Manifold bolts   Check engine light STILL on after vacuum repair...ABS too   Intake?   Water in Intake 
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Re: Torque sequence & pound spec's-Intake manifold gasket re

Postby ASTE25 » Nov 25 2011, 10:18pm

This will not sound very professional, or precise, but it's how I have done it in the past and have had no problems. I start tightening them by working from the center bolts outward, either in an "X" pattern, or in a circular motion (either clockwise or counter clockwise). As far as torque, I'm not sure what it specifies, however, I just got mine a little tighter than "snug". The main thing is, with these plastic manifolds, you do not want to overtighten them, causing them to break or crack. This is really an easy job. It looks hard at first, but really shouldnt take more than a couple hours. This design is really nice, since you do not have to mess with any sealant. Be sure not to drop any trash into the intake runners when you have the intake off and to clean the sealing surface of the heads really well before you go back together with it (usually a rag soaked with some brake cleaner works well).
Jordan
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Re: Torque sequence & pound spec's-Intake manifold gasket re

Postby blue_fin1 » Nov 26 2011, 3:32am

for the silverado its 44 inch lbs first time around and 89 inch lbs second time around
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Re: Torque sequence & pound spec's-Intake manifold gasket re

Postby 2001_gmc_sierra [OP] » Nov 27 2011, 6:29am

Thank you both for your advice. I started and finished the job today. I did the x pattern thing working towards the outside, and tightening the bolts to 44 lbs, then 89 lbs. After I put everything back together the truck started right up. It runs like new.

Jordan - you are right, at 1st I was amazed at all the things in the way, but after you start pulling one thing off at a time it's not so bad. For me the hardest thing I had to deal with was the fuel injection electrical lines. At first I couldn't figure it out, but there was a gray clip on each that you have to pull on really hard, but once they're off the connection comes right off by squeezing the clip. Otherwise the new gasket seems better than the original one, although I did get 134K miles out of the origanal one. I'm hoping to get another 134K miles, if not more now.

Thanks again guys...

My next project on this truck is a new fuel pump. Did either of you ever change the fuel pump on your trucks? If so, any advice? The reason I'm changing it is the Low Fuel message, and the fuel guage bounces all over the place. About a year ago I let the gas go really low, and ever since then the fuel guage never worked the same. I've been putting it off since the fuel pump is about $275, but I plan on keeping the truck so figured I should fix it now, especially since the truck runs so good after fixing the intake manifold air leak...
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Re: Torque sequence & pound spec's-Intake manifold gasket re

Postby ASTE25 » Nov 27 2011, 6:45am

Glad to hear you got it done and it all went well. Actually the one I worked on was not my truck, but one I made a few bucks fixing. I just put a fuel pump in my neighbors truck a couple weeks ago. I would reccomend staying with an AC Delco brand pump. The aftermarket ones do not last very long. When I priced a pump for my neighbors truck Advance Auto Parts wanted around $330 for an AC Delco. I did a little shopping around on the internet and found an AC Delco on Amizon.com for about half what Advance Auto Parts wanted. I will warn you, when you get the new pump you will have to cut and splice some wires, as GM has redesigned the plug and terminal end on the new pump. Aparantly the old design was prone to corrosion (must be up north, because I've never seen a problem here in Alabama with them). Luckily I have a vehicle lift, and that makes it really easy to work under the truck. There are two ways you can go about it, depending on where you are going to work on it. (1) lift the truck up and drop the fuel tank. If you do it this way, try to have the fuel level down to at least 1/4 tank. (2) Loosen the truck bed from the frame and move it back to where you can access the top of the fuel tank to replace the pump. I have never actually done it by removing the bed. Whichever way you decide to do it, be sure to use compressed air to blow the dirt and trash off the top of the tank near the fuel pump so it does not drop in the tank when you remove the pump.
Jordan
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Re: Torque sequence & pound spec's-Intake manifold gasket re

Postby blue_fin1 » Nov 27 2011, 7:00pm

I did my fuel pump (AC DELCO bought on amazon) on my truck. I removed the 4 bolts that hold the bed on and slided the bed back 4ft with my neighbors help and use a jack stand to help stablze the bed while I changed the pump. when I splice my conections I doubled heat shrinked them. that was about 40,000 mile ago here in the north east 2 winters worth. And while your at it I would do your fuel filter to.
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Re: Torque sequence & pound spec's-Intake manifold gasket re

Postby 2001_gmc_sierra [OP] » Nov 27 2011, 7:21pm

Sounds great. Yeah, I'll probably go with the AC Delco...I'll look on Amazon like you guys suggested. I'm planning on doing it after the holidays, but once I'm done I'll let you know how it went. Thanks again, and have a good holiday if we don't chat again :)
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