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EA82 intake manifold bolts bottom out


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It appears that the intake manifold bolts will bottom out. I am installing a rebuilt EA82 and am meticulously researching each step. All I want is for all to go well. I have chased the intake bolt holes [as advised by General Disorder] and noting the depth. Adding in the thickness of OEM gaskets I see barely one or two bolt threads available before bolt bottoms out. That can't be right, can it? I don't believe that washers were used, but that might not be a bad idea.

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47 minutes ago, rickyhils said:

It appears that the intake manifold bolts will bottom out. I am installing a rebuilt EA82 and am meticulously researching each step. All I want is for all to go well. I have chased the intake bolt holes [as advised by General Disorder] and noting the depth. Adding in the thickness of OEM gaskets I see barely one or two bolt threads available before bolt bottoms out. That can't be right, can it? I don't believe that washers were used, but that might not be a bad idea.

I just recently redid my intake manifold. The OEM bolts come with a flared head base but do not use a washer. The clearance is tight but the gasket is thick enough, at least in my case. I would recommend chasing the threads and cleaning up the bolts as best you can.

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No washers. 

Here's the money question - why are you measuring the bolt?

If it's because you have mixed up bolts, count and make sure the number of matching bolts equals the available slots.  Post a pic of the bolt(s) in question.

Measure again, 1 to 2 threads of engagement is a tiny amount.  I've installed hundreds of that exact bolt on countless subarus with no length or install issues.

This is highly unlikely and would require significant material to bottom the bolt, but If the heads intake mating surface, or intakes head mating surface, have been filed or resurfaced or cut that would shorten the bolt path.

 

Edited by idosubaru
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Different bolt hole depths as pics show. The same bolt was hand tightened on both old engine and newly installed rebuilt. As a newby I am for sure overthinking this, as I don't want to mess anything up!      A plastic straw inserted shows hole depths the same on the old and the rebuilt.  I flushed out all holes with brake cleaner.  All I can think of is that the threads furthest down on the rebuilt might be compromised. I did NOT want to thread chase the rebuilt beyond what seemed safe. I used a 3/8 drive with a light touch until it seemed to bottom out. Then I gave it another five or ten degrees max.  This needs more research.

* Other notable points - The history of this rebuild is unknown. I picked it up for $100 bucks as it had the signs of a quality rebuild. And I figured that even if the bottom end craps out [due to incorrect bore, wrong oil clearances, etc.] I still have two good rebuilt heads, good oil pump [not sure if new], new water pump, two sets of timing belts [ Three Star brand] and new OEM intake and exhaust gaskets.

* By the looks of it this might have been rebuilt maybe 10 or more years ago, meaning that bottom end crank parts were still available.

* Head gaskets definitely NOT Felpro perma torque, so I have a ground down 17 mm socket for re-torque after running up to temp. Rebuilder added some reddish brown gasket sealant at far ends of head gasket for maybe water area, well away from cylinder seal. That might be another sign of an experienced rebuilder. Not sure.

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Got it.  I think you said that the two engines have the same hole depths?  That suggests the holes are fine and points us to focus on the bolts and manifold thickness. 

Can you post pictures of them - do the old and new bolts match, have the same grade, and appear the same length and tread to bare shaft ratios?

do you have a caliper that you can measure the depth of the intake manifold bolt hole areas, if they're accessible?

2 hours ago, rickyhils said:

 

Different bolt hole depths as pics show. The same bolt was hand tightened on both old engine and newly installed rebuilt. As a newby I am for sure overthinking this, as I don't want to mess anything up!      A plastic straw inserted shows hole depths the same on the old and the rebuilt. 

 

I'm having a little trouble following what's going on.  First sentence says different bolt hole depths, last sentence says hole depths are the same.

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It seems there’s an issue with the thread at the bottom of the hole, or some debris down there stopping you from getting the bolt all the way in. 

You might need a thread chaser with a straight edge on the leading face to get to the bottom of the threads in each hole. A tapered end won’t do the job. 

Have you sat the intake manifold on with the gasket in place and checked to see if the bolts can be torqued with contact on the intake manifold? 

When you fit the manifold, don’t forget that pesky little coolant hose from the top of the block. It’s a PITA to get to with the manifold on, but not impossible. 

Cheers 

Bennie

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The intake manifold and all six bolts are coming from the old engine [1991 Loyale] . 4 months ago I redid those manifold gaskets and all went well.   FWIW- when I bought the rebuilt, the guy also gave me a box of a few extra parts which included a carb manifold. Does that offer any more clues?

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Bennie , I hear you, mate.  My thread chaser is home made using a bolt with a slot ground out at the "1 o'clock" position. I will cut off the end where the taper starts to make it a straight edge. I have an extra ea82 head to try it out on.

Tightening one bolt down to where it first meets resistance has play in the manifold, so must be debris at bottom.

And yes, that pipe that connects coolant to the heater from the top of the water pump. Those pipes get corroded just a bit. Will check that curved piece of short hose to the water pump.

And I won't make the PITA mistake of not first getting that short EGR pipe in position before bolting down the manifold. Been there, done that. That's my Indian chauffeur - Ben Der Dun Dat.  

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idosubaru-   I'll try to clean out debris . l'll put some PB blaster in there for while then use a soft metal rod to break loose any debri then blow in some brake cleaner.

And, as we all have learned [hopefully not the hard way] to COVER UP OR PUT A RAG INTO THE CYLINDER HEAD INLET.  It is painful to even imagine that somewhere sometime somebody had dropped a bolt in there. Doable to use a magnet for retrieval, but the REAL upset is if one is NOT SURE if anything actually fell in there.

And, all you guys here are a great resource of knowledge and experience. Thanks a bunch.

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I am unable to fix those bolt holes. Will consider the approach on shortening the bolts. There are 13 or 14 threads in play as designed to hold the torque. If I then have only, say 11 or 12 threads, would that be enough to hold the clamping pressure needed? And, just so I can get this engine up and running to verify that the rebuild was ok, do I dare just adding two threads width of washers on the bolt heads? I know that is a mickey mouse work around. Then if engine is a winner I will cut the bolts by 3 to 4 mm.

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Finally ! Someone includes some measurements !

Dunno where you read that on bolt length problems.

Most will be about threads fusing between head and bolt, 

or bolt shank corroding to Billy oh! fusing to inlet manifold

On rebuilds I have used Teflon tape on shank where manifold contact can be. Also just kept going with copper grease on threads and up shank

If heads shaved most likely need to enlarge hole dia in manifold for these bolts or they won't go in nice and square. I feel the larger dia hole gives better air gap to reduce corrosion occuring again for some time

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13 minutes ago, Step-a-toe said:

If heads shaved most likely need to enlarge hole dia in manifold for these bolts or they won't go in nice and square. I feel the larger dia hole gives better air gap to reduce corrosion occuring again for some time

Steptoe is talking about the intake manifold bolt holes, not the ones on the head ;) 

Cheers 

Bennie

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Step-a-toe,  Certainly shaved [surfaced] cylinder heads will alter the intake manifold Left/Right bolt alignment. That issue is not what I have. It turns out that an obstruction at the bottom of the bolt holes is preventing manifold bolts going in the final two turns. Manifold and bolts are ok. The acquired rebuilt long block has some corrosion debris at the very bottom of the holes. I am doing a workaround using two washers on each bolt. This rebuild looks competently done. I just want to get it running to see how if it holds up.

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Ok, think I get it, you see thread in the hole to a certain depth but you found bolt won't run to the end of this thread?

Plug tap M8 1.25 pitch to clean threads up?

I admire your end of the spectrum of checking stuff.

At the other end of another spectrum, we have guys with dirt floors, stirring up dust as they work :)

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On a different matter.   At the radiator filler tube , I see the coolant level very slowly dropping down until it is level with the throttle body, then it stays there. I am guessing that I may well have a bad throttle body gasket. The "horse shoe" rubber gasket?   Thanks

Edited by rickyhils
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On first issue, just seeing your query in a different light.

Were you concerned that some threads still remained above threaded parts surface when you fully screwed in?

Coolant levelling question...jack vehicle front up a foot higher at front - any change?

Time frame for initial coolant level to be found?

If horseshoe seal leaking, coolant will run down to cylinders, so look in plug holes

Some have even made one corner of car highest point. Front left, to bleed air

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53 minutes ago, Step-a-toe said:

Were you concerned that some threads still remained above threaded parts surface when you fully screwed in?

No, he’s saying that with the intake in place the bolts seem to bottom out before any torque is applied to clamp the intake manifold to the head. 

Cheers 

Bennie

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Yeah, measuring the bolts in my case was only for finding out how much muck might be at the bottom before going for a reliable final torque. And using some sticky tape at the end of a straw I was pulling out a few specs of a corroded bolt and even a bit or two of blue RTV. That RTV can be evil stuff when used in the wrong hands. ha ha

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Step-a-toe       re: Coolant leveling question...jack vehicle front up a foot higher at front - any change?   I will try that and get back with the results.

What happened yesterday is when I filled up the cold engine with coolant to the top of the radiator filler tube it then would then slowly run down to the bottom of the filler tube over a 5 minute time span. Then when I would start the car with the cap off, the coolant would quickly come to the top again. NOW - compare that to today where I filled the coolant to the very top of the radiator fill tube. I clamped off the hose going to the overflow recovery container for this test. After more than 1 hour the coolant has lowered only by 1/16th of an inch. Not withstanding any evaporation. 

Some have even made one corner of car highest point. Front left, to bleed air.  So, maybe I have a little trapped air. I did make sure to squeeze all water hoses when first filling it up.

Edited by rickyhils
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There is always trapped air.  Until the thermostat opens, and the water pump can move significant volume of coolant.  I got one of the no spill funnel filler things that attaches to the radiator cap, it helps a lot with getting all of the air out.  

Fill the radiator.   Squeeze the upper radiator hose to pump air out, top if as needed.  Let the engine idle until the thermostat opens.   Keep an eye on the coolant all along.   Rev a few times once it's opened.   That should get most of it.

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