Intake Manifold Bolts

[DV-523]

Hey! I'm a newbie here, I bought a 89 Subaru GL wagon a couple weeks ago and have been working on the head gaskets. When pulling the intake manifold off I broke one of the bolts. I know the two long ones on the other side are going to break as well, they have not been cooperative. I can get the studs out, but where do I get the new manifold bolts? I can't find them anywhere.

[moosens]

Some of us may have them. I know I just went through a miscellaneous nuts n bolts box to help fill out a flat rate shipping to one of us and I’m pretty sure I have some from various years and models. 
 

But looking at them I couldn’t pinpoint which goes to what. 
 

So if you can add a pic with measurements. Two are long and four are shorter. You know that. Or maybe I don’t know , geez might be the opposite. Brain fart.
 

Best to use penetrant and heat , turn IN just a touch and then out , spray , heat , repeat over n over little at a time working it out. And of course you’re going to find being on the east coast that oxidation has chalked up the entire stem , threads look like hell and no way are you using it again and likely (certainly) have to deal with the holes. 
 

Some of us go to heli coils , others like me go to a Timesert or equivalent. Especially if you expect to carry forward long term. Find your favorite kit and go at it. 
 

Good luck. Drills , easy-outs , you’ll get there. Many of us have suffered the same. Just like 18 years ago or so. 

Edited July 9, 2020 by moosens

[DaveT]

Get the whole block & head up to normal operating temp, 170-200 F - check with a meat thermometer, thermocouple, or IR thermometer.

I usually do this by running it before I loosen the bolts.   When I am working on a non runnable,  I've used an old style space heater along with a heat gun to get enough heat.  You don't want hundreds of degrees in one spot, you want operating temp deep inside, where the threads are.  So it takes a while to get it there.

Then proceed like moosens wrote.   I have yet to snap a bolt when using this trick.  And some of them were incredibly stuck & corroded.

One thing that's tricky to learn, but if you can  - get to know the feel of a bolt springing as you twist, vs yielding, which is what happens right before it snaps.  You can push them into the springy area, but once you get to the yield, the fatigue leads to breaking them.

[GeneralDisorder]

Make them yourself. All-thread, nuts and washers. Easy. 

GD

[Step-a-toe]

A good bolt supplier. I bought a set in stainless to try

Only problem is heads come in 13 not 12 mm

I was thinking a drain hole drilled in the side of each bolt and a fill hole to blow spray lube straw to prevent further corrosion, or future corrosion I should say

Same idea may work for tricky stuck bolts, as most, but not all of my problems were stuck in manifold, not the thread stuck

Edited July 10, 2020 by Step-a-toe

[idosubaru]

I grab them off extra engines, without that, post a parts wanted post, look online for that thread pitch M8x1.25 (8mm x 1.25 pitch) and length, or fabricate your own bolts to work. 

 

I've had zillions of sheared off and stuck ones.  I've been able to get a lot of stuck ones out, that would shear, by rocking them back and forth like so:

1. tighten them just a few degrees to break some corrosion

2. loosen them as much as the corrosion allows - 45 degrees or 90 degrees

3. turn back that 45 or 90 degrees

4. continue walking the bolt back and forth and closely increasing the range at which it's loosening.  go from 45 degrees to 90 to 135 to 180...etc. 

5. After a few iterations - go do something else to let the localized heat disperse so it's not internally heating up too much.  Give it at least 15 minutes to cool down. 

6. Wash-rinse-repeat those steps

7. once the bolt head gets above the intake manifold quirt some penetrant down the shaft of the bolt. 

8. continue working it out. 

 

 

[DaveT]

I would be VERY wary of using stainless bolts in aluminum.  The corrosion that happens between the 2 metals is WAY worse than rust from steel bolts.

[Step-a-toe]

1 hour ago, DaveT said:

I would be VERY wary of using stainless bolts in aluminum.  The corrosion that happens between the 2 metals is WAY worse than rust from steel bolts.

Yes, been told this and was curious last time I pulled them.

Nothing to be concerned so far

[DaveT]

Did you apply anti seize?   That will slow it - regardless of the bolt metal.
The corrosion won't happen dry, but if water gets in there, that's when the corrosion starts.

[GeneralDisorder]

All thread with nuts - then you have studs which aren't going to be as much of a problem in the future. 

GD

[Step-a-toe]

12 hours ago, DaveT said:

Did you apply anti seize?   That will slow it - regardless of the bolt metal.
The corrosion won't happen dry, but if water gets in there, that's when the corrosion starts.

I didn't the first time but did on refit once I heard the chances of corrosion possibly worse

[Step-a-toe]

7 hours ago, GeneralDisorder said:

All thread with nuts - then you have studs which aren't going to be as much of a problem in the future. 

GD

Good idea and reasoning.

Does bring back memories of Triumph TR7 with corroded head studs, nuts removed and block and tackle trying to lift head off block, just enough to get a hacksaw between head and block

[scoobydube]

Get some bolt loosener and let it sit overnight after liberally spraying.

[Scoby4wd]

I just went through this.  I managed to pull them all without breaking them.  The key was to loosen them like a 1/8-1/4 turn at most, just enough so that you create the slightest gap between the head of the bolt and the manifold.  I did this by very slowly and light working them back and forth until I could get that slight gap.  Then I sprayed CRC Freeze Off, waited a minute or two, and started working it again.  Repeated this a couple of times and they all came out no issues.

[idosubaru]

On 7/13/2020 at 1:38 PM, scoobydube said:

Get some bolt loosener and let it sit overnight after liberally spraying.

That doesn’t do anything here.  these are long bolts, top will be sealed shut at the head and the corrosion is way below that and if the corrosion is thorough it’ll be over a long portion of the entire shaft so it needs relatively drenched to have any chance of soaking down the entire corroded shaft length. 

That’s why my description, and the previous comment, mention working the bolt back and forth to get it backed out enough to get fluid under the head of the bolt. Wash rinse repeat a lot.  If it’s real tight take breaks to let localized heating dissipate. 

[DaveT]

What Scoby4wd wrote, regarding fractional turning + what I wrote about heating.   idosubaru also, the penetrant won't get through all the crud, if they are really bad.   The reason the heat helps so much is that aluminum expands more than steel at the same temperature.  Rust & corrosion expand, that's why they get stuck in the first place.  Keeping within normal operating temperatures means seal, etc. are not damaged, along with metal characteristics.

[idosubaru]

10 hours ago, DaveT said:

What Scoby4wd wrote, regarding fractional turning + what I wrote about heating.   idosubaru also, the penetrant won't get through all the crud, if they are really bad.   The reason the heat helps so much is that aluminum expands more than steel at the same temperature.  Rust & corrosion expand, that's why they get stuck in the first place.  Keeping within normal operating temperatures means seal, etc. are not damaged, along with metal characteristics.

+1, penetrant isn’t necessary or the key here.  No need for it. I use it sometimes down the shaft, maybe speeding things up a little towards the end.

[GeneralDisorder]

Honestly it's typically easier to just snap the suckers off and drill them out. Assuming you have the skills to core it with a drill bit right down it's axis and save the threads. I've done this so many times at this point that I'm about 90% at drilling out broken/rusted/etc fasteners and saving the threads. 

GD

[Step-a-toe]

21 hours ago, idosubaru said:

+1, penetrant isn’t necessary or the key here.  No need for it. I use it sometimes down the shaft, maybe speeding things up a little towards the end.

Penetrant won't work in some of my worst, they have been like hard brown mud, expanding into the space they had, outgrowing it's space ..no room for anything to soak through

[UnorganizedMechanic]

Pardon my intrusion, I seem to be in a similar predicament.  I just got a Brat after 20 years of waiting only to find a seized engine and dried coolant crud throughout the system. The 2 long bolts on one side of the intake manifold of  snapped the heads off upon attempted removal. So I soaked it in penetrant oil, the drilling got FUBAR and askew, torched it, whacked at it to loosen it, and tried to gently pry it. After crying a bit, I took a slide hammer with an old coil spring compressor end to grab into the water neck opening and gave it all I got to pull it up and out...to no avail. Maybe half a millimeter of movement. Then more tears. Then by brain thought it could be a good idea to cut into the intake bolts. My theory was to cut the binding and rusted tube in half, thus making it twice as easy to release the kraken. I'm still crying and debating cutting deeper or yanking harder, or buying a new motor. Thank you for shopping at Subaru. Good luck everybody. 

 

Edited March 22, 2022 by UnorganizedMechanic

[idosubaru]

drill them out.   

you could try cutting down the length of that aluminum as far as possible and then just wedging a chisel into your cut and wailing on it until it brakes, or spreads open, that ear.  Repair or replace afterwards. 

i see it's all hogged out - otherwise, i would keep drilling.  i'd probably try a punch and a tiny bit to see if i can get it centered.  or a large bit and use it to flatten out the central area as much as possible to then use a tiny bit.  or just use a large bit and drill all the way down as-is and repair or replace the intake once you've got it all off.  

the alumnium will drill out far easier than the shaft of the bolt. 

high quality drill bits are key, i just ask a machinist friend to point me int he right direction and buy a set online, i don't buy stuff from local box stores for stuff this bad.  i have one dedicated set of drill bits for situations like this that i don't use for anything else.  keep the drill tips cool, lubricate them and give them many breaks if necessary to cool off.  otherwise they'll heat up and dull quicker. 

Edited July 24, 2020 by idosubaru

[UnorganizedMechanic]

On 7/24/2020 at 11:00 AM, idosubaru said:

drill them out.   

you could try cutting down the length of that aluminum as far as possible and then just wedging a chisel into your cut and wailing on it until it brakes, or spreads open, that ear.  Repair or replace afterwards. 

i see it's all hogged out - otherwise, i would keep drilling.  i'd probably try a punch and a tiny bit to see if i can get it centered.  or a large bit and use it to flatten out the central area as much as possible to then use a tiny bit.  or just use a large bit and drill all the way down as-is and repair or replace the intake once you've got it all off.  

the alumnium will drill out far easier than the shaft of the bolt. 

high quality drill bits are key, i just ask a machinist friend to point me int he right direction and buy a set online, i don't buy stuff from local box stores for stuff this bad.  i have one dedicated set of drill bits for situations like this that i don't use for anything else.  keep the drill tips cool, lubricate them and give them many breaks if necessary to cool off.  otherwise they'll heat up and dull quicker. 

That's where my head is going.  Just keep drilling, just keep drilling.  La la la la la.  Dory said it best.  Best case, I have to JB weld repair the slot, second best, break that punk intake off hoping the bolts come out nicely then replace the intake.  I'm off to find some magical drill bits.  Thanks for the encouragement @idosubaru!

 

Edited March 22, 2022 by UnorganizedMechanic

[Step-a-toe]

Went through this with long sat EA81, including bent push rods due to fresh fuel leaching gum varnish from barnacles inside tank. The whole coolant side full if crystallized crud, one head had a half peanut size hole corroded into face.

I repaired, had a strong quiet engine on new HGs for 3 months let had myself a steam engine.

Basket case. Salvaged nothing and scrap yards it to save any others grief

[UnorganizedMechanic]

I'm so sorry if I hijacked this thread DV-523!  I hope your repair is successful.

I agree with all the other guys about replacing and removing bolts.  Penetrant oil helped me as well as heat.  A good hardware or fastener store locally is where I source my automotive bolts.  A good place should have a variety of bolt types like zinc coated, stainless and whatnot.  If all else comes together I'll be liberally applying anti-seize to the shaft of the bolt in the intake manifold, torquing everything to spec, and double checking for air and coolant leaks.  I'm going for a full rebuild if the cylinders aren't garbage and crossing my fingers.

VICTORY IS MINE!  After hours or heartache and cussing and possibly bending the intake manifold, it has succumbed to my will.

 

 

 

Edited March 22, 2022 by UnorganizedMechanic

[GeneralDisorder]

You do realize that a "full rebuild" is essentially impossible due to lack of parts right? The oil pumps for the EA81 have been discontinued for many years now. 

GD