Loose intake manifold bolts.


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By 55charliebird - 7 Years Ago
As I was watching the bird running today and it was idling rough, I noticed a small bubble coming from the intake manifold in the area of the 3rd cylinder on the driver side....directly in line with the carb.  The bolts are the ones with the spacer.  I shut it down and found both of them loose.  I will let the engine cool completely down.  QUESTION   Should I loosen all intake bolts then retighten them in sequence?  I prefer not to remove the manifold.  This rough idle just seemed to appear.  No coolant is evident, anywhere. 
By 55charliebird - 7 Years Ago
That is what I was planning.  Just break the bolts loose, slightly, then re-torque to proper specs. If it idles ok, I'll consider it fixed. 
By Gene Purser - 7 Years Ago
It takes pressure to make a bubble and the intake passages should have vacuum. You were probably looking at the center manifold heat riser. I don't know where the bubble could come from unless it was condensation. 
By 2721955meteor - 7 Years Ago
sounds like over kill,just go over all the  intake bolts,tighten the ones for the bridges  first then cover them all. if you suspect a intake  leak after this squirt a bit of oil around the intake potion. as the bridges clamp the exhaust more heat there, be sure the studs are  not stretched  . i would use some hardened flat washers to be sure the nuts are not running out of thread.if this does not cure the problem remove the manifold and be sure there is no warps,
By paul2748 - 7 Years Ago
If you loosen the manifold, you run the risk of creating a leaking coolant situation at the front.  Just,tighten the center bolts (the "bridges") and then go over all the bolts according to the recommended procedure (start at the middle and work to the ends).  If that doesn't solve the problem, then remove the intake and install new gaskets.
By Pete 55Tbird - 7 Years Ago
Before you get yourself too wound-up why not measure the manifold vacuum? KISS. "Keep it simple stupid." Pete
By Ted - 7 Years Ago
55charliebird (8/4/2018)
As I was watching the bird running today and it was idling rough, I noticed a small bubble coming from the intake manifold in the area of the 3rd cylinder on the driver side....directly in line with the carb.  The bolts are the ones with the spacer.  I shut it down and found both of them loose.  I will let the engine cool completely down.  QUESTION   Should I loosen all intake bolts then retighten them in sequence?  I prefer not to remove the manifold.  This rough idle just seemed to appear.  No coolant is evident, anywhere.

If you’re talking about the two center intake manifold bolts on each side that go thru the bridges (I call them turtles), then those particular threaded bolt holes in the heads are not always blind holes and do occasionally break into the water jackets within the heads.  Coolant leaks at those locations are sometimes mistaken for leaking head gaskets.  Ford used studs at those center locations on each side and I’ll recommend using sealer on the threads to eliminate the possibility of coolant seepage at those locations.
 
Ditto on the other comments about tightening.  Simply retighten.