Oil pump screws: I hate them
 

https://www.miataturbo.net/attachmen...ine=1318904130

This is with one of those impact screwdrivers from the local autoparts store. What do?

Cry.

weld 1/4 nuts the them, use wrench on nuts.

:2cents:Lots of heat. Then push, twist, and pray.

Use a real impact tip, should be darker color, like the impact sockets:
https://www.miataturbo.net/attachmen...ine=1318905045

Make sure the tip is fatty and fits in the head nice and tight. Don't pussy smack it like Fae. Attach Hustler's 5lb nuts to the end of a stick and hit it like a man. (aka use a 5lb sledge).

Also realize if you can't get the nice tips, you might be wasting 5 brand new tips, one on each screw.

i have the same issue with those screws that hold on rotors and when that happens i use a cold chisel and a hammer and one good tap and they come free.

Kris.

https://www.miataturbo.net/attachmen...ine=1318905231

^^ That + new screws.

(The cheap-ass Harbor Freight kit worked getting broken 10mm bolt out of cylinder head.)

I got a proper darker bit and it decided it was going to round out the screws even more. I also have a nice swelling spot on my hand after I hit it with the sledgehammer.

This is next. Probably tomorrow though. I need a drink.

Just drill the heads off. Flat head cap screws are cake to drill out. Obviously clean everything VERY thoroughly afterward.

Fuck those things.

Buy a reverse drillbit and be amazed at how well it works.

I will never even attempt to use an EZ-out - those things are harder than any drill bit I own. I would much rather just drill the head off whatever bolt broke, then extract it easily with a set of pliers once the preload is off the threads.

Like Curly suggested, the proper tip with a small sledge is what I've used in the past on tricky screws as well.

Once you start rounding them out, its over.

The tip of one of those is now permanently embedded in the head of my '92, surrounded by the remains of one of the two bolts that used to hold the lower thermostat housing in place.

Honestly, I don't think I have ever successfully removed a stuck fastener with one of those.

For the ones already rounded, my money here is on carefully drilling the heads off of the screws, removing the cover, and then using a vise-grip on the part that's left. That said, I have in the past been successful with the technique already mentioned, vis-a-vis a proper impact bit and a sledge. The secret is to hit the tool with the hammer- hitting your hand with it does not help get the screw out.

And will make a preacher cuss in front of his mother.

+1 for reverse drill bit. Or use a drift punch to smash the mangled bits flat to the heads again and get manly with it and wack it like a wife. Just remember all the mornings waffles weren't ready and get angry. Sometimes some heat helps.

This may be my preferred method of removing oil pump screws now, even if the cross pattern is perfectly intact.

1: Drill a hole deep enough that so that you almost sever the head of the screw from the shank. I used a 15/64" Left hand drill bit. (Sadly, the bit didn't catch and magically remove any of the screws on it's own.)

2: Use largest screw extractor of your Grabit set with a small gearless socket wrench.

3: Pie.
https://www.miataturbo.net/attachmen...ine=1318988100

I found that once the majority of the screw head was removed, it's structural integrity was compromised enough that I felt comfortable with the amount of torque required to break it loose using the extractor.

Has anybody sourced a Torx replacement for these screws?

I got mine from McMaster Carr, its been awhile so I don't remember the pitch, size, or length. But here: http://www.mcmaster.com/#socket-head-cap-screws/=ek6aux

Heat always works.