It doesn't seem logical, but one of my head bolts is smooth, has something in the head, appears too smooth to be a broken bit-tip, but I guess it could be.

Going to have to grind it out, definately hardened steel. Is there any way of grabbing the outside of the head bolt on a 603? It is beneath the cam tower, so no easy way to grind it, ... any suggestions welcome. Drill bits for "hardened steel" haven't made a divot and my center-punch just flattened (really hard too, made from a carbide spot-face bit).

Maybe a carbide drill?

__________________

Gone to the dark side

- Jeff

Someone may have tried to use a torx bit instead of a triple sq and broke it off? Fun one....you can purchase diamond coated bits too although its going to be slow going regardless.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Sears has these things that look like a socket and fit on your ratchet. they have teeth inside and will fit over the bolt head. As you try to loosen the bolt the teeth bite in to the head of the bolt. They work great. I wish I could remember what they were called, but if you look with the extraction tools at sears you'll find them

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“Fundamentally, sustainable development is a notion of discipline. It means humanity must ensure that meeting present needs does not compromise the ability of future generations to meet their needs.”--- Gro Harlem Brundtland


1989 300se 250,000
1983 BMW 528e 100,000
1999 Olds Alero 80,000

These pretzels are making me thirsty.

Thanks jeffoc, I'll look at them. The trick is going to be getting something that will fit into the counterbore in the head, and get enough grip for ~100+ ft-lb of loosening.

I did grind one down with a die-grinder, perfect fit, certainly appears to be a triple-square, two bolt heads were this way and the metal filling the head is exactly flush with the top. Wierd, like someone didn't want it removed again.

I considered trying to stick a welding rod to the center and then pull it out, chances are it would simultaneously weld the mass into the bolt head, and possibly the threads to the block, not enough room to try brazing, probably go with the hardest drill bits I can find (already spent $40 on drills).

Sometimes the easiest things become the biggest PITA.

__________________

Gone to the dark side

- Jeff

When I went to take the head off my 617, someone had attacked exactly HALF of the head bolts previously with a Torx bit. Perfectly smooth inside the cap

I spent two hours with a low-speed drill and a simple titanium bit ($4 or less) drilling the caps off. Each one launched up the bit with a satisfying *THUNK*.

Lifted the head straight up, unscrewed the studs sticking out of the deck by hand. Easy as can be expected.

Just make sure all of your oil passages are blocked up, stick a magnet in a plastic bag and pick up the shavings often to take the risk of contamination down. The bag is so you can remove the shavings from the magnet - and there will be a lot.

If you have any used oil laying around, dump some in a spray bottle to irrigate the bolts while drilling. A friend helps with this fun little project.

Don't know how that differs from a 603 -- but my two cents anyway.

__________________
Vehicles:
2002 SLK 230
Gone but not forgotten:
1983 300D
1981 El Camino 'OILBRNR' - 6.2L diesel
OM617 powered '86 F150
1984 BMW 524td
2001 VW Beetle TDI
1994 Sunurban 4x4 6.5L diesel

Those things are great. I have a small set that came in a blister pack and I threw the label away, so I don't remember what they are called. They have a hex head on the outside (for use with a wrench or socket) and the inside is shaped like a tapered helix.

__________________
1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!

I'll third. Sears should have a stud remover tool big enough to bite onto the bolt head and get it out.

If that does not work then (carefully) grind the head off down to the shank and that will take the tension off it.

Grinding is not an option, the bore in the cam tower is roughly 7/8" and 2-1/4" deep to the head of the bolt. The mass in the bold head is apparently the end of a hardened-steel bit, just mushroomed the end of a quality center-punch and hardened "cobalt" drill bits don't make a mark.

I'll look for some of the internal-helix sockets, hopefully they'll fit in a 7/8" bore to get the bolt head out and handle 100ft-lbs or greater to break it loose.

Fingers crossed.

__________________

Gone to the dark side

- Jeff

not very likely.
those rounded nut sockets do not work on round internal bolts. they are WAAAAAY too hard, and there is no leftover flats for the socket to grab. even if it were to be on a nearly perfect hex head, I don't believe they would turn the MASSIVE torque needed to pop an MB head bolt out.
ya best just start planning on a drill out method...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

I don't know how much the differ on the diesel from the gassers. But I had to use one when I removed the head from my 300se. Stripped out two of them. Considered drilling it for a while but worried about the shavings.
I Had to buy the biggest set that they have. They are hardened. Worked like a charm.
Best of luck let us know how it turns out.

__________________
“Fundamentally, sustainable development is a notion of discipline. It means humanity must ensure that meeting present needs does not compromise the ability of future generations to meet their needs.”--- Gro Harlem Brundtland


1989 300se 250,000
1983 BMW 528e 100,000
1999 Olds Alero 80,000

These pretzels are making me thirsty.

In our machine shop at work, we have a tool called a "Tap Burner", that is sort of like a primitive EDM machine. This thing will burn out any tap, cobalt drill, broken bolt, etc. Ours is on a pivoting arm, similar to a large drill press.

Perhaps you can find a local machine shop with such a tool. Positioned correctly, it would burn that bolt out in 5 mins, with no other damage.

SteveM.

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'93 190E/D 2.5 Turbodiesel 5-speed (daily driver)
'87 190D 2.5 Turbo rustbucket - parts car
'84 Dodge Rampage diesel - Land Speed Record Holder
'13 Ram 2500 Diesel
'05 Toyota 4Runner

Thought about the EDM method, but didn't know there was such a tool for burning taps out etc. Good thing to keep in mind.

I searched all of the high-end tool suppliers in town, burned an hour or so, nobody had them. Finally found a couple of sets at Autozone, bought them.

They don't fit in the cam tower, I had to OD grind to remove the hex, then the 14mm fit. Worked great, smacked it on with a brass mallet and extension, turned the bolts out one-at-a-time and replaced with good bolts, then removed the bolts in the correct pattern.

Finally have the #22 head off and ready for the machine shop, THANKS to jeffoc and others who suggested the internal-helix type bolt remover, big big help over drilling slowly with expensive carbide bits and having the bolt smap free.

Drinks are on the house.

__________________

Gone to the dark side

- Jeff

Home Depot sells the same small kit as Sears ($20). Sears sells an extended kit, twice as many sizes, for $60. Either kit is cheaper than a trip to the mechanic.
You might have to use gently, a 3/8 inch air ratchet to get enough torque, but only as a last resort.
Lots of PB Blaster and patience.
Good luck.
Paul