Intake Manifold Bolts

[76okievette]

On my 1976 it appears that I have a oil leak around two intake manifold bolds. It is the two bolts on the right side (passenger side) that are in the middle of the manifold under the carb. I can't get a seem to get a wrench on them to see if they are tight or not. Do I have to take the carb off to tighten these bolts and is it possible that they are leaking oil around the bolt?

 

[bossvette]

I usually use a swivel socket, there is no oil under pressure in that area. What you are seeing is oil from the lifter galley that is seeping thru possibly your intake gasket needs replacing.

Craig sr

 

[mvftw]

Just did mine. You need a 9/16 swivle socket. Beware...the 4 corners go into the water jacket. They do break! I broke both front bolts...not a pretty site...All fixed now

 

[76okievette]

Thanks I will get the swivle socket and see if I can tighten them up. As always I appreciate the great response from this forum.

 

[JohnZ]

Very common issue - hot oil mist from the lifter valley migrates up the bolt threads (which are exposed in the lifter valley) and wets out under the bolt heads as stains, which eventually become little pools. Pull the bolts one at a time, clean them, put some non-hardening thread sealer on them, and re-install. Just use a box wrench on the center two bolts on each side; the extreme four corner bolts don't need the sealer, as those are blind holes.

 

[drags1998]

DITTO!!!!!!!!!! Johns rite on the money!!!!! When re-installing bolts DO NOT OVERTIGHTEN 38 Lbs. MAX

 

[76okievette]

Thanks everyone, I was thinking I would just go ahead and remove the intake manifold and replace the gaskets, I also have some oil seepage all along the manifold. Is there any problems that I will run into when I remove the manifold? I know about marking the dist so that the timing will be close when I reinstall. I guess from what JohnZ said in his reply that I should put some non-hardening bolt sealer on the manifold bolts when I reinstall. I was planning on getting new bolts for both the manifold and for the carb.

What about a new manifold, what does everyone recommend if I decided to go with a improved manifold? I am leaning toward keeping everthing orginal but a little more proformance would be nice. The car is a 1976 L-48 by the way. Thanks again.

 

[Cream79L82]

Edelbrock

I just put a an aluminum Edelbrock Peformer EPS on the '79 this summer. It's hard to isolate the singular effect it had though because I also went to a new Edelbrock carb as well. I can tell you the aggregate effect is a lot smoother operation and a lot snappier acceleration along with more pull throughout. I also had problems with leakage after putting on the new gaskets. I finally decided to tighten the bolts more than the 12-15 ft/lbs that Edelbrock said were max. I'm pretty sure they want to err on the side of caution though.

A new intake looks great and isn't that hard an install. Just don't drop any wrenches into the heads...

-Jon

 

[mvftw]

To make life real EZ, go get a set of Stainsteel Bolts from Summit.

 

[JohnZ]

I also had problems with leakage after putting on the new gaskets. I finally decided to tighten the bolts more than the 12-15 ft/lbs that Edelbrock said were max. I'm pretty sure they want to err on the side of caution though.
-Jon

That torque spec had to be a mis-print - it's not even CLOSE to correct; no wonder you had leakage problems. Those twelve bolts are 3/8"-16 x 1-1/8", and the correct torque spec is 25-35 ft-lbs.

 

[Cream79L82]

Yeah, that's what I thought it had to be. I mean.. it's a cast iron or steel block right? I wonder if Edelbrock was assuming an aluminum one, which also doesn't make sense.


okievette... whereabouts in OK do you live?

 

[drags1998]

Someone recommended stainless bolts, MY advice is to stay away from stainless ANYWHERE on the engine. When you torque a standard bolt to spec. it streches, and that is what keeps it from loosening!!!! Stainless bolts DON'T strech!!!. I learned this the hard way! I bought a stainless bolt kit AND was always tightning the oil pan,headers,intake and even the water pump. I finally changed all the bolts and no more problems!!!!!!!! (P.S. these were ARP bolts which my opinion are by FAR the BEST!!!!

 

[76okievette]

Cream79L82, I live in Norman, north part up by Rock Creek and Porter. I just replace the intake bolts and sealed them I will see if that works. What about Corvette Clubs wife and I are thinking about joining one can you make any recommendations?

 

[Cream79L82]

Okie, I joined Sooner Corvettes last year, namely because of their name, but I find it wasn't a very mutually beneficial relationship because they're based in McAlester and I'm a student here at OU. I haven't done much research on the different clubs available around here. My guess is there is a pretty good sized one in the OKC area, I just don't know about it. Sorry for the lack of info.

 

[76okievette]

No problem, I have talked to one memeber of the club in the city, I think its Central Corvettes of Oklahoma something like that, when it warms up again I think we will join. Let me know where you hang out I would love to see your car sometime. Thanks for help. GO SOONERS!!!

 

[bossvette]

try NCCC for a list of Corvette clubs
http://www.corvettesnccc.org/

 

[76okievette]

Sloved problem, I just wanted everyone to know I fixed my problem of the oil leaking out around the two intake manifold bolts. I fixed them just like I was advised here in the forum. I remove the bolts cleaned them put some thread sealer on them and reinstalled, leak as gone. Thanks guys that was much eaiser and faster then a intake removal.

 

[George Black]

Should any "special" type of non hardening thread sealer be used for the middle 4 intake bolts--due to heat, etc? or just any name brand thread sealer?

Best to use new intake bolts, or just remove, clean and reintstall the old ones?

Thanks!

 

[mvftw]

I used Stainless Steel grade 8 bolts and teflon pipe sealant on All threads...

 

[George Black]

Sloved problem, I just wanted everyone to know I fixed my problem of the oil leaking out around the two intake manifold bolts. I fixed them just like I was advised here in the forum. I remove the bolts cleaned them put some thread sealer on them and reinstalled, leak as gone. Thanks guys that was much eaiser and faster then a intake removal.

Thanks to 76okievette, JohnZ, and others! I fixed my problem of hot oil mist migrating up & leaking out around the center 4 intake bolts! I followed the advice and procedure in this forum. An easy fix. JohnZ identified the exact cause of the problem!--clearly seen when I removed the bolts and observed how much oil was on them. Thanks guys.--G.P.Black