[danveloce]

Greetings! Preparing to take my fuel injectors out for, from the looks of it, the first time in 80,000 miles and the bolts holding them in are not moving even with some moderate force. They’re the Allen drive heads and as you can see a similar one already snapped off on top of the engine so I’m a little hesitant to put a lot of force on these. I’ve been putting penetrating oil on them for almost a week and nothing though kinda to be expected since there’s really no gap there.

Seems like a bad place to use a torch or heat gun right next to the outside of the fuel injectors and, you know, there’s still fuel in those individual lines. I have Allen bits I could put on an impact wrench but that seems like a bad idea too… Any suggestions, or just put some more force on them and hope the heads don’t twist off?

 

[ghnl]

Which penetrating oil are you using? WD40 is useless for this, I like PB Blaster or Kroil. I've read that a 50/50 mix of acetone & ATF might work even better.

After applying one of the above daily for 3 - 5 days, try first applying some force in the 'tighten' direction. If it moves even the tiniest bit stop and re-apply the penetrating oil then try in the un-do direction. After 1/8th of a turn re-apply the penetrating oil and keep working it forwards & backwards with frequent applications of the penetrating oil. Be sure to use a few Italian curse words (with appropriate gestures).

 

[danveloce]

Which penetrating oil are you using? WD40 is useless for this, I like PB Blaster or Kroil. I've read that a 50/50 mix of acetone & ATF might work even better.

After applying one of the above daily for 3 - 5 days, try first applying some force in the 'tighten' direction. If it moves even the tiniest bit stop and re-apply the penetrating oil then try in the un-do direction. After 1/8th of a turn re-apply the penetrating oil and keep working it forwards & backwards with frequent applications of the penetrating oil. Be sure to use a few Italian curse words (with appropriate gestures).

Oh yeah, thanks to this forum I’ve been using PBlaster on the many stuck fasteners on this car. In this case for about the past week once or twice a day.
I haven’t yet tried tightening though, nor any Italian curse words (only English and plenty of them). I’ll give both a shot in the morning, thanks!

 

[GradBrad]

You'll want to be super careful not to strip out the Allen head on those bolts, which may be a greater likelihood than snapping off the bolt itself. At 80k miles, all mine came out easily except one, and that one stripped. A bolt extractor worked to remove it.

 

[Del]

The slight torquing back and forth over a period of time technique is a good one to learn, and is how one can successfully remove the three long V6 thermostat housing bolts, which are sometimes frozen in place. This back and forth torquing, and a mild banging on the bolt head with a hammer, will often do the job. Just plain wrenching to unscrew them causes some to end up with sheared off bolts.

Lol, decades ago I asked my Italian mechanic why he swore in english (American?) instead of Italian. He said that when he was p*ssed at something, the english words were much more succinct and instantly "explosive" in releasing emotion at that point in time, as he kind of snapped with anger. He thought the Italian swearing was more like insulting stories, where you were trying to diss someone. Thought that was very interesting, and still remember what he said.

 

[Mborras1]

I just finished that job a few weeks ago access is limited and having the correct size Allen is key. Make sure u pb balst the crap out of it also u will be better off removing the coolant housing for better access. Make sure your Allen is straight in and flush with the bolt use air to blow them clean. Try not to use extensions u want to be as close to the bolt as possible for max torque and and slowly with force try and crack them free. I believe they are 5mm Allen. Once u get them out evaluate whether to get new hardware your local Ace will have them. One of mine stripped off so I had to use a torks a tad bigger to get it out.

 

[GreenSpider91]

I had to use the “hammer a torx in” method on three of the 8. My mistake was likely not getting the Alan key 100% straight before removing the intake. I would have instead used an impact driver to remove but messed that up..

 

[Gubi]

Yeah, I don't know if there's room for a manual impact driver, but if so that would probably be the safest and most effective way.

Normally I'd say to use heat but that's awfully close to the plastic of the injector. I suppose you could make a metal heat shield and then use a tiny butane torch. This is the one I use for precision work like that.

Amazon.com: Weller Mini Butane Torch - WLTBUM2 : Everything Else

Amazon.com: Weller Mini Butane Torch - WLTBUM2 : Everything Else

www.amazon.com

 

[danveloce]

I do have some ratchet hex wrenches so I might indeed try a manual impact thanks! Also considering using the “welder” (260W electric soldering iron) I got to melt the hoses off to just heat up the bolt. I know that’s the opposite of the part of this I want to expand but unless it might crack the housing maybe it’ll give enough movement to loosen things up?

 

[Del]

That's why rapping a little on the heads of stuck bolts can help. The shock loading transmitted to the threads, along with the back and forth torquing, can sometimes slowly break them loose from corrosion or whatever is holding them stuck. Obviously, you don't really bang on the heads, don't want to do any damage.

 

[spider87]

I've probably removed about 200 fasteners from my '87 in the last couple of weeks as we take this thing apart. That one screw you are having problems with is the only one in the whole engine bay that gave me problems. Even with the valve cover removed, so I could work on it with no limitations, the screw sheared off and ended up needing to be mostly drilled out and finished off with an ez-out. I don't know why that one screw would be so difficult for both you and me, but ...

The other two screws that caused problem so far were the outboard rear Phillips #3 screws holding down the seat rails. Symmetric on both driver and passenger sides, so there is a pattern - not just random. One of those needed to be mostly drilled out, the other came with persuasion from vise grips after drilling off the cap.

 

[danveloce]

Misery loves company @spider87. Actually the one you see sheared off there was broken when I got it! Only after removing plenum and such did I find it and the washer wedged against the side of the engine. Must have been there for at least the 500 miles I’ve driven it over the past year. Funny that it’s the exact same one.

@Del thanks for the encouragement! Am continuing to tap them, using the widest punch I have that will easily fit inside the head due to smaller than hammer head clearance around basically all of them. Been doing that after putting rounds of PBlaster on, hoping it might shake some oil down in there. Tempted to try tapping on the washers next to see if I can get any play in them (their ID is close to the OD of the bolt but should move a tiny bit at least). I figure I’ll give this another couple days before dialing up the force a little And crossing my fingers. Thanks all!

 

[spider87]

Misery loves company @spider87. Actually the one you see sheared off there was broken when I got it! ...

Actually mine was broken when I got it too - my son (who bought the car, and is working with me on it) had broken it off already. I assured him it was OK and would probably happen a lot ... but noooo.
But it was really stuck in there. It's an M6 screw, and I probably used about a 5mm drill and EZ-out to get it out of there (had been trying a smaller size EZ-out and backed off since I was applying so much torque and really did not want to snap off an EZ out in there).

 

[danveloce]

But it was really stuck in there.

I'm very tempted to weld another screw on top of it and leave what's in there there. Nobody will see it!

 

[4sfed]

I'm very tempted to weld another screw on top of it and leave what's in there there. Nobody will see it!

You're almost there . . . weld a nut to the remains of the screw and use that to remove it. The heat may be all you need to break it loose. Works well even when the screw is broken slightly below the surface. If the nut breaks off the first time, try again. Concentrate the heat on the screw, the nut has no heatsink and will easily melt.

The lower exhaust studs need to be removed to resurface a head and are notorious for being difficult. I have used this method dozens of times.

 

[danveloce]

On the stuck injector bolts... Anyone think it might be worth me putting everything back together again and running the engine for a while to safely warm up the housing they're stuck in maybe enough to make a difference and make them easier to remove? I'd just go ahead and try it but it'll probably be a couple hours of work for me so checking with the well-informed hive mind first...