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Discussion Starter #1 (Edited)
HELP! Intake manifold gasket replacement?

Hi, I have a 1981 C3 with 61,000 miles. The intake manifold is starting to weep at one of the corners and bolts are tight (I checked them). I anticipate this problem with all chevys, but would it hurt to use a radiator sealant to slow or stop the problem? I started dismantling the engine and couldn't believe all the vacuum hoses and wires. Is there a good product to stop this leak? I hate to tear the engine down. Thanks for any help. -Dan
 

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try using a teflon paste or red RTV on the bolts; make sure all of the bolt and inside threads are squeaky clean . . . good luck
 

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Discussion Starter #3
Thanks Shari, I'm concerned that it might be coming out between the interface of the manifold and head - not the bolt. Have any other ideas?

Dan
 

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I hate to say it but your going to need a new one. They don't get better. Even if stop leak or a similar product did work now, the chances are that the gasket is deteriorated and will start leaking elsewhere. I've also heard stories that stop leak et al. can actually plug some of the smaller passages going from the block into the head but have no experience with this myself as I don't use the stuff.
If you need help with the replacement post up for help along the way.

steve
 

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Any of the stop leak products will (IMHO) eventually plug up passages in the radiator, heater core, and anything else that has a small orofice foor the coolant to get thru. Best (not easiest) is to bite the bullet and fix it right. If you don't have time to fix it the first time, when will you have time to fix it again?

:cheers:
 

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Discussion Starter #6
Thanks Steve. I started on this and can't believe the work involved. My biggest problem believe it or not is moving the air cond. compressor AND air pump out of the way, with all their hoses and wiring. A little concerned about the distributor removal as well. I'm not seeing any coolant in the oil yet.
 

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Puting the destributor back in is no sweat. If you have a problem, we'll help. It might be time to tune it up, while you have it apart. something to think about. Good luck :cheers:
 

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Discussion Starter #9
I have done this work on my 81. PM me or post a question.
Thanks for your assistance! The biggest problems right now are:

1. Removing the air pump to access all manifold bolts up front.

2. How do I move the fuel line, and other metal lines out of the way so that I can pull the manifold?

Any other problems I might encounter? Thanks. -Dan
 

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Disconnect the metal line from the pump.
You have to take the AIR pump and bracket off, since it shares a manifold bolt.
If you are going to do all this work, I suggest an Edelbrock Performer manifold. It is available with EGR and swaps with no mods needed.
You can wait till it's off to see how corroded the stock one is.
I can post pictures of re-assembly.
You must be carefull of how you re-assemble the smog pump bracket. It is aluminum, and done out of order, it can snap at the manifold.
Let me know which manifold you use.
 

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Discussion Starter #11
Thanks a lot. I AM concerned about the aluminum manifold being corroded. If so, is it not repairable? Also, I am trying to keep the car stock as possible.

1. Did you remove your air pump permanently? Does this affect the value of the car? It would be nice to chuck it.

2. What does the edelbrock manifold do so well? Have a link for it?

Thanks again. -Dan
 

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Thanks a lot. I AM concerned about the aluminum manifold being corroded. If so, is it not repairable? Also, I am trying to keep the car stock as possible.
You can use devcon to renew corrosion around the water ports.
1. Did you remove your air pump permanently? Does this affect the value of the car? It would be nice to chuck it.
No. It's still there. Kalifornia:D
2. What does the edelbrock manifold do so well? Have a link for it?
Not alot. Just new and cheap.
Thanks again. -Dan
http://store.summitracing.com/partdetail.asp?part=EDL-3701&autoview=sku
 

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With a lot of hoses, brackets, etc., it would help you later if you took a bunch of photographs before you really get it ripped apart.
 

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Disconnect the metal line from the pump.
You have to take the AIR pump and bracket off, since it shares a manifold bolt.
If you are going to do all this work, I suggest an Edelbrock Performer manifold. It is available with EGR and swaps with no mods needed.
You can wait till it's off to see how corroded the stock one is.
I can post pictures of re-assembly.
You must be carefull of how you re-assemble the smog pump bracket. It is aluminum, and done out of order, it can snap at the manifold.
Let me know which manifold you use.


BIG2BIRD, I AM GETTING READY TO PERFORM THIS SWAP. WHAT DO I HAVE TO WATCH WHEN REMOVING THE AIR PUMP? YOU HAD MENTIONED TO BE CAREFUL. THE BRACKET LOOKS DELICATE. BY THE WAY, I'M WRITING FROM ANOTHER ADDRESS AS I COULD NOT LOG ON TONITE! APPRECIATE YOUR HELP.... DAN
 

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Removal is easy. Take pictures, it will help you. The AIR bracket needs to be checked for fit when you re-install.
Use thread sealant on all bolts. They will weep oil if not. Use small SAE washers under the bolts. Use Edelbrock gasket set. Use Gaskacinch to glue to heads. Use Blue RTV silicone,small bead around water ports, and 3/8" bead on top of China Walls. DO NOT USE the end gaskets. Throw em away.
Do not install carb till you tork the screws. Pass side middle is a b---h.
Use thick gasket for carb. Still available from GM. Do not use any other.



 

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Removal is easy. Take pictures, it will help you. The AIR bracket needs to be checked for fit when you re-install.
Use thread sealant on all bolts. They will weep oil if not. Use small SAE washers under the bolts. Use Edelbrock gasket set. Use Gaskacinch to glue to heads. Use Blue RTV silicone,small bead around water ports, and 3/8" bead on top of China Walls. DO NOT USE the end gaskets. Throw em away.
Do not install carb till you tork the screws. Pass side middle is a b---h.
Use thick gasket for carb. Still available from GM. Do not use any other.



I HAVE A SHOP MANUAL BUT IT ISN'T THE GREATEST HELP.

1. I BOUGHT RED RTV, MAY I USE THAT? WON'T THE RTV KEEP THE GASKETS IN PLACE OR DO I NEED THE GASKASINCH?
2. ALSO, IF I DECIDE TO KEEP THE STOCK MANIFOLD, IS THERE ANY REASON TO REMOVE THE CARB? (MY EGR VALVE IS RUSTED PRETTY GOOD....CAN I REMOVE THAT BOLT WITH THE CARB IN THE WAY IF I USE A BOX END WRENCH?)
3. FINALLY, IT LOOKS LIKE I HAVE TO REMOVE THE ENTIRE AIR PUMP BRACKET. SHOULD I REMOVE THE INTAKE BOLT FIRST AND THEN LAST TO REINSTALL?
4. DO I NEED TO TOUCH/REMOVE THE AIR COMPRESSOR?

THANKS FOR THE PICTURES ALSO - DAN
 

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I HAVE A SHOP MANUAL BUT IT ISN'T THE GREATEST HELP.

1. I BOUGHT RED RTV, MAY I USE THAT? WON'T THE RTV KEEP THE GASKETS IN PLACE OR DO I NEED THE GASKASINCH?
2. ALSO, IF I DECIDE TO KEEP THE STOCK MANIFOLD, IS THERE ANY REASON TO REMOVE THE CARB? (MY EGR VALVE IS RUSTED PRETTY GOOD....CAN I REMOVE THAT BOLT WITH THE CARB IN THE WAY IF I USE A BOX END WRENCH?)
3. FINALLY, IT LOOKS LIKE I HAVE TO REMOVE THE ENTIRE AIR PUMP BRACKET. SHOULD I REMOVE THE INTAKE BOLT FIRST AND THEN LAST TO REINSTALL?
4. DO I NEED TO TOUCH/REMOVE THE AIR COMPRESSOR?

THANKS FOR THE PICTURES ALSO - DAN
1) Red is fine. I believe the blue is more oil resistant. I prefer the gaskacinch. It's kind of like contact cement.
2)Yes. (The carb gasket if not torn can generally be re-used).
3)Yes. Re-install both bolts to align, then tighten pump bolt first,or you will snap it at the intake lug.
4) No. You may need to loosen the bolts though.
 

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Okay, well I start this project today. My father is a past Chevy mechanic so he offered to assist. (I just wanted to get everything lined up before I called him in....he's not touched engines for a while. I'm 40 and he is 67.) Attached is a pic of the car and the engine in particular. I have a "stray" green wire near the air pump that we could not locate a hookup point. The car is bone stock but this thing was just hanging out. Any ideas? You are a great help.

Dan
 

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The "stray" green wire is for testing the dwell of the feedback carb. It connects to nothing, but is needed for testing.:thumbsup:
 

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Also, take note that many 81 parts are 1 year only. The stock manifold, the AIR diverter valve, the carb, the EGR solenoid, ALL hard to find and expensive.
 
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