Removing Busted Exhaust Manifold Bolt

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AlanB

Guest
Hey Guys:

Looking for any advise for removing a busted manifold exhaust bolt on my 92 RRC. The bolt is broken off about flush with the head from what I can see with the manifold still on, it is the passenger side rearmost bottom bolt, not much clearance. I have ordered all new hardware and gaskets and will probably break off more bolts removing the manifold. Any tips and tricks will be greatly appreciated as I am dreading this job.

Thanks,

Alan
 
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t77911s

Well-known member
Sep 16, 2004
400
0
Alan, The only thing I know to do is to drill out whats left of the existing bolt, then retap. Hopefully someone else has a better solution. Regarding the attachment of the exhaust manifold, I saw on a Discovery II, it uses a different type of bolt. Has anyone tried this new style bolt on the RRC's? I have a constant problem of my exhaust bolts loosening, requiring a retorque. I've tried the factory lock tabs, lock washers, and loctite. Has anyone tried using a stud/nut combination?
 
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AlanB

Guest
Thanks Tim, that's what I had in mind, but it is really tight in there for a drill, may have to get a 90 degree drill?. I really do not want to remove the head if possible.
 
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Sirfoss

Guest
Turn

Alan
I have run in to this allot and 9 out of 10 times once the manifold is off the head you can spin the bolt out. The head of the bolt is what holds all of the pressure so once gone the threaded area comes out easy. If you do have to drill use L/H drill bits and reverse the drill and normally it will grab and out comes the bolt.
Mike :eek:
 
ptschram

ptschram

Well-known member
Sep 27, 2004
21,955
50
In the shop doing the Lord's work one broken Rover
www.ptschram.com
I have also run into this situation on several occasions, but not with the same results as Mike.

If it won't come out using vice-grips, etc, pull the head! It is very difficult to drill in those quarters.

If you do decide to try to drill it as is, when you realize how far off-center the bit has gone, tap the hole to 7/16-14 and use a stud with 7/16 on one end and 3/8 on the other.

I would not suggest using an easy-out, when they break, they are much more difficult to remove from the bolt.

I just got real lucky drilling out two on the same engine, both times I was successful, not something that happens every time.

Peace,
PT
 
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AlanB

Guest
Thanks for the advise Paul, if the bolt is stuck in the head, I am going to try the bolt extractor bits I got at Sears which I think is far better than the old easy out method.
 
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alia176

Well-known member
Sep 14, 2004
68
0
Tijeras, NM
Alan,

Would you have better access to the broken bolt if you removed your exhaust manifold completely? If you need a tight space drill, look into a 90deg pneumatic drill. These things have decent torque for smaller bits, very small package and easy to work with in tight spaces. Expect to pay around $90 for a good quality one.

Ali
 
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AlanB

Guest
Thanks everyone for the advise.

Ali, yes a 90 degree air drill would have worked great, but I purchased the Milwaukee close quarter drill and it worked great, but pricey.

We removed the exhaust manifold, only busted one additional manifold to head bolt in addition to the one that was already busted. I soaked the three y-pipe to manifold bolts for a couple of days with some penetrant and the nuts came off easily without any broken studs. The manifold bolt that I broke upon removal was easily removed with some heat and vise grips. Now comes the fun part.

The already broken stud (passenger side rearmost bottom) was sheared off just inside the head. We first tried using a fancy sears bolt extractor with no luck, then tried an easy out style extractor, no luck, bolt was not wanting to come out. So we just drilled out what was left of the bolt and used a 3/8"-16 helicoil (same size as stock bolts). Bolted everything back up with new gaskets and bolts, no more leak and noise. We chased all the head threads with a tap as some of old bolts upon removal did not come out very clean looking, did it just on a precautionary note. Thinking back, we probably could have drilled out the bolt and tapped it for a larger bolt size instead of using a helicoil, but the helicoil worked great and keeps the stock size bolts.
 
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