Stuck intake manifold bolts

[300SD81]

Anyone have any tips on getting these 2 out? One I can't get to with the hex socket, and I'm probably just afraid of busting my hand with the allen wrench, but the other one is really stuck and I don't want to round it out.

I'm already soaking it in kroil, but with the length of these bolts, I'm not sure if it'll actually get down to the threads...

[Hit Man X]

You need extended length allen/hex bits

7 Pc 3/8 in. Drive Metric Long Reach Hex Bit Socket Set

Something like those. Use a breaker bar on them, from memory only the inner four hold the upper to lower together. I foresee a pressure washer in your future.



FYI, if you are emission exempt... TIG up the AIR injection bung on the top and the EGR on the bottom. Do not be shocked if the EGR is already plugged due to soot.

[lsmalley]

Make sure to clean any debris out of the hex bolt so the hex fits all the way down into the bolt otherwise you run the risk of stripping the inside. Use a small pick to scrape around the inside and then compressed air to blow it clean

[Hirnbeiss]

Looks like you have good enough access to use a hammer impact driver like this one. Mine saved many a cheesehead screw on motorcycle crankcases from a mangled death:

Craftsman.com

[300SD81]

Yep.. pretty much what I figured out yesterday Got one out after pounding in a 1/4 (6.35mm) bit and using my impact wrench on it. Had to order a longer one to get access to the other bolt. Won't be here until tomorrow night.

EGR hole is about to become idle air for my megasquirt install

[97 SL320]

Steel bolts tend to dig into and become " glued " to aluminum. The trick is to break the stiction before trying to remove the bolt so you only have tension to deal with. This isn't a case of the bolt being too tight.

Use a flat punch that fits into the hex, hammer to compress the aluminum / stretch the bolt head a bit. If you don't have one that small, a large one that contacts the head is OK but may slip off so be careful.

Another method is to hit the head 90* to the threads. This will also loosen the stiction.

I've also used a semi sharp flat chisel to spin difficult bolts. In this case you need to dent the head with the chisel then engage that dent to spin the bolt.

In severe cases, have someone put some rotational pressure on the wrench while you strike the side of the head but be aware that it may suddenly break free..

The last bit is if you don't have an impact driver / have to use a long extension ( long extension act as a torsion bar and absorb rotational force ) use a breaker bar and hammer on the breaker bar head so the force is directed at the bolt head.

[optimusprime]

On my m103 engine i have three of these allen bolts holding the engine lifting eye .This is right at thr rear of the engine righthand side .My allen bolts would not move ,and rounded off .I did all i could. I knew they had to be removed to get the lifting eye off ,on the rear was this O ring that was leaking coolant. Just picked up this long chissel 2 foot in length with a slight bend on the front end . ie chissel [ was not straight ] it was bent in such a way , when i hit it with the hammer, it opened it , with no problem