janarvae

'91 L98 auto.....I had another thread open about my 4 broken intake manifold bolts (manifold still on) and how to go about removing them, but it was 4 pages long and I didn't want people to have to re-read all 4 pages.

I chose to drill with progressively larger cobalt drill bits and then pound a #2 square extractor into them for removal with t-wrench. I successfully drilled two of the bolts (two front-most bolts on passenger and driver's sides) and had them nice and in the middle of the bolt. Pounded in extractors and BOTH extractors broke when trying to remove with t-wrench!! I pounded them in more than 1/2 an inch each, which is considerable for a #2 extractor, and they still could not handle the stress. Now I'm feeling pretty hopeless - I have broken bolts on all 4 corners of the intake manifold with the 2 forward corners having extractors stuck in them.

Should I use a large drill bit and drill down the remnants of the old bolts and the hardened extractors down to the heads so that the intake can be lifted off? I also don't have access to a welder.

Cliffnotes: 4 broken intake manifold bolts at each corner of the intake. Intake manifold is still on - rest of bolts are removed. 2 frontmost bolts have been drilled and #2 square extractors snapped in them. HELP!

Pictures: I linked them to make this dial-up friendly....
Front Passenger

Front Driver's

Rear Driver's

Rear Passenger

Aggravated4life

Never mind,I read too fast...

Had to edit...ok,even with the extractors in there,if all other bolts are out,can you still try and lift off the manifold before drilling the broken extractors out?

janarvae

Well, they are at such an angle and there is so much crud in the bolt holes (intake manifold bolt holes are not threaded and a little larger in diameter than the bolts) that it would be very hard to pry out. Regardless, I tried and failed epically. I tried a flat-head screwdriver in the front intake china wall area and on the sides using the valve covers as leverage to no avail. I think the crud stuck within the intake manifold bolt holes is what caused the stress when removing the bolt. On the passenger front one, the head was still on, but then I pounded in a larger torx head (t-50) and snapped the head off of that one today.

Is there any other way to pry it off? I went with a very slim pick and cleaned the area surrounding the bolts inside the intake manifold non-threaded bolt holes, but there is still a good amount surrounding the bolts there. I am sure that once the intake is off, the bolts will come out without issue. It is the crud on the four corners from a leaking water pump and a bad rear intake seal that has given me this problem (my theory).

In some of the pictures, you can clearly see the crud that has set around the bolts, making it difficult to turn the bolts.

Thanks for looking,

Jonathan

engle1147

That looks like a real nightmare you got going there! I guess you don't know your own strength.

I feel your pain.....we've all been there.....small jobs can turns into a nightmare real quick.

Well, looking at the photos you may want to take a different approach....you'll have a hard time drilling out those extractors since they are so hard. And those busted bolts look like they are broken off too low to weld something to them with the intake in place. If all that's left is broken bolts how about unbolting the heads and lifting every thing off then working on extracting the bolts on the bench. Yes I know this is a lot of work and doing so will require new head gaskets. Best of luck with that.

janarvae

I was thinking of exactly that! Gosh, I'm going to need some higher flowing heads, new valve covers, 1.6 RRs, a more aggressive cam, new timing chain, cover, gasket, LT headers, new cats, a MR, and then maybe, just maybe, I'll be done. Oh, and I forgot '91 head gaskets are next to impossible to find now.

P.S. How hard is it to remove the heads? This is my first time going this deep into any car, but, just like my tranny rebuild, if I put my mind to it, I'll do it.......eventually

engle1147

Unbolt the exaust manifolds........pull the plug wires....remove the valve covers.....drain the engine coolant......unbolt the rockers......remove pushrods....and unbolt the heads. Piece of cake!

Oh and your car will never be done 'cause there is always some way left to tweek it for just a little more power!

Iroc57

Intakes can be stubborn so it may not be the broken bolts holding on. Have you used a hammer handle or similar in the runners and given them a good tap to break it loose? Much better leverage and less chance of damage to the aluminum than a screwdriver.

Just a thought

Aggravated4life

Theres a very good chance corrosion set in on the threads and the studs are stuck at the corners by the water jackets.

If its that bad,and you manage to get the heads off,please let a machine shop take the seized studs out that are stuck in the heads.

Btw,use at least a foot long 1/2 inch breaker bar to loosen your head bolts.Dont use the smaller 3/8 tools.
You reduce the chance of breaking something with a larger bar with better leverage.

If you buy/use the breaker bar and dont have a 1/2 inch socket,you can buy an socket-sizer adaptor to let the smaller 3/8 socket fit onto the larger 1/2 inch breaker bar.

janarvae

I put the end of my 2 ft breaker bar in there already and pulled up with all my might.......and........nothing. Do you mean give it a tap inwards or somehow tap the handle from the bottom (kind of difficult). I tapped it up by quickly lifting the end of the breaker bar - at the moment I was thinking "F' it - I'll get a new intake if I mess this one up!" I've cooled down since and am ready to get this off without damaging anything.

I truly believe if I can get all the crud out surrounding the bolts in the intake, it will have enough play to lift off even though the bolts are at an angle. Is there any other alternative to pulling the heads and intake as one? I've been at this for 4 months now (tranny rebuild included) and am ready to drive a CORVETTE again. I've used PB Blaster galore and it really hasn't affected the crud. Any caustic agents I could use? Would Simple Green be sufficient to break it down and then use a pointed wire thin enough to fit between the bolt and intake bolt holes?

If it wasn't for these *!#$^$@ bolts, I would have been driving the car 2 weeks ago!

chucks88

I don't think it is possible to remove the heads with the intake still on.

Here's a thought. spray the crap/Heat several times in order to remove the remaining 8 bolts. The intake should come right off since the heads are gone from the other four bolts and there are no threads in the intake holes(just in the heads)

Then you can re-evaluate what you need to do to get the 4 broken shanks out.

If need be at this point you can pull the heads, drop them off at a machine shop and pay somebody to remove them.

janarvae

Rest of the bolts are off- its only these 4 corner bolts that are still on!

steve40th

Use some PB Blast on the intake bolts, extractor and get reverse(left handed) carbide bits(use Tap Drill oil to help cut). I just went through this, and you need small ones to start and get bigger till extractor gets in there, or one that has a starter bit on the end, and use a damn good drill.
And you can use a welder and weld a bolt on the end of the extractor and slid hammer it off (washer and socket). I did this to the crank bolt.
Then weld a new bolt to the old bolt in the manifold and turn them out after PB Blasting them

chucks88

gotcha. in that case.....what I've done in the past is the following.. I have taken wooden hockey sticks or at least the shafts of one, stuck it in the intake runner ports and lifted up. I would work my way around all of the ports until it popped loose. you can also rap the intake with a dead blow hammer to help break the bond.

janarvae

I'll have to give it another go tomorrow using that technique.

engle1147

That might work I know a good hockey stick is strong as hell....like a good hammer handle.....but looking at the photos the intake bolts are not broken off at the cylinder head level they are broken off even with the upper level of the intake manifold.....the bolt's shaft is still going to grab the intake and hold it in place due to the angle of the bolts. I'd give the hockey stick thing a shot....it might work....then if that fails pull one of the heads and try again.

Redeasysport

I dunno if you have tried this put PB Blaster it and torch it several times and I mean torch till it starts to glow then try prying up on it. It looks like you have peened the bolts with the extractor so it may not work but it is worth a shot at this point. Heating it with the PB on it will get it to soak in better.If you get it to move at all squirt it in the crack between the intake and head and repeat.Try sharpening a good putty knife to an edge to get in the crack if you can.When all else fails get a good torch and start cutting time for a new intake.

856SPEED

I don't know what your budget situation is like, but with the time, trouble, and headaches you have taking the intake out, I would think you could have saved yourself a million in stress by having a professional mechanic take it off in minutes with the proper knowlege and tools....just reading your post makes me stress....I feel for you....good luck with everthing...I'm sure it will all turn out fine in the long run...

jfb

The best penetrating oil I have ever used is Kroil and I recommend it if you are going to use penetrating oil. Broken EZ outs cannot be drilled as they are harder than any drill bit except tungsten carbide and TC drill bits are very brittle and usually shatter when you drill by hand. Better success will be from using a milling machine, heads bolted to table. Broken EZ outs should be ground out or removed by electro discharge machining. Always use the largest EZ out you can without touching the threads. I highly recommend the electro discharge method which does not harm the threads that the new bolt will have to engage. EDM (electrodischarge machining) won't be cheap, but it will save your parts which aren't cheap to replace if one of the other techniques damages the threads.

AGENT 86

Wow, that's a bitch of a situation. I think your chances of unbolting the heads and removing the works, is slim to none. The dowel pins between block and head, will make that job, futile.
This is what I would do at this point.
Put on face shield.
Take a center punch and hammer and crack/chip the extractor, until it is all out.
Drill bolts flush to gasket.
Pry off base.
After the base is off, you can continue with the bolt extraction techniques.

Ed Ramberger

Get some KROIL and let them soak overnight. It's the best I have found. Check out KANO Labs.