Need help with a stuck engine mount bolt

[LeeG]

I am trying to help out a friend of mine here. He has an 03 BMW 745Li that he is working on. The issue is the lower drivers side engine mount bolt. He has been unable to remove it. Apparently, initially he tried removing it, and it got rounded off. Then he tried welding a nut on. That probably should have worked, except he only has a tiny HF 120v flux core welder, and my thought is that it just didn't have the power to get good penetration on the bolt.

Here is what we have to work with.

View media item 98036
There isn't much room to get in there to work. I can't even get my hand in there. He doesn't have a lift, so we are working laying under it on the floor.

Any suggestions on how to get this off?

Thanks,
Lee

 

[SGKent]

I hate photos at angles like that, they look more like a hole than a nut or bolt. If that is a bolt then we are looking at the bolt with the weld that was left when the nut he welded on came off. Napa has sockets for rounded bolts and nuts.

 

[zkdiesel]

I hate photos at angles like that, they look more like a hole than a nut or bolt. If that is a bolt then we are looking at the bolt with the weld that was left when the nut he welded on came off. Napa has sockets for rounded bolts and nuts.

BMW is know to have titanium engine mount bolts. See if other ones he removed are stupid light..... if so welders not the hot setup

Is it reversed in a whole and it was a torx?

 

[LeeG]

The bolts appear to be magnetic (at least the replacement ones are). They are an E-Torx head.

 

[zkdiesel]

The bolts appear to be magnetic (at least the replacement ones are). They are an E-Torx head.

Is the failure the bolts broke and that’s why he’s changing them?

 

[matt_i]

Can you show a pic of the replacement fastener? It looks like a socket-head internal torx drive.

And that is going to be tough to handle. I am not sure there's room but I'd try to core out or die-grind deeper into the head so it eventually pops off leaving a stud...that hopefully can be handled with a left-hand drill bit or a straight fluted ez-out....if a pilot hole can be attempted.

If the mount is bolted elsewhere it might be easier to try to remove the engine with that bolt intact. It might involve sacrificing the engine mount by dremel-cutting a slot thru it so the fastener can be removed out the side.

Bad place for a stripped head. The blue wrench would help but before you get to that state...

 

[LeeG]

Here is what the fasteners look like.

View media item 98047

 

[lostmind]

Air chisel, looks like you have room. The part that remains should unscrew with your fingers once the tensions off and the mounts removed.

 

[SGKent]

I have on occasion used a dremel to put new edges on a hex to fit a slightly smaller socket. An air chisel might work, I thought of that but if it doesn't there is no turning back. I might look at a larger nut, and another weld attempt.

 

[BillK]

Here is what the fasteners look like.

View media item 98047

So it looks like the head of the bolt is completely gone in your picture ?? I think the only way you are getting that out of there is to drill it a little at a time until you get to the size of the new bolt and then the mount should come off and give you more room to get to what is left of the bolt.

How many bolts hold the mount on ? Are the rest of them out already ?

 

[mjeff87]

I'd definitely try the damaged bolt head extractors pictured (I have 2 sets, one from NAPA and a Craftsman set). They've saved my bacon more than once. Get the smallest one you can that will start to slip over what's left of the head and pound it on. Might try heating the mount some around it, and use a jack under the engine to try to gently get the weight of the engine off that mount side as much as you can.

 

[BillK]

Did you guys even look at his picture ? There is nothing left of the bolt head to use those types of tools on The bolt is broken off down in the hole in the mount.

 

[joe_padavano]

Did you guys even look at his picture ? There is nothing left of the bolt head to use those types of tools on The bolt is broken off down in the hole in the mount.

Unless I'm missing something, I had exactly the same reaction as Bill. Time to start unbolting whatever can be removed around that mount for more access. What's on the other side - does the bolt thread into a tapped hole or is there a nut? Frankly, it looks like time to unbolt the mount from the frame and pull the motor to access this problem on the stand.

 

[SGKent]

Unless I'm missing something, I had exactly the same reaction as Bill. Time to start unbolting whatever can be removed around that mount for more access. What's on the other side - does the bolt thread into a tapped hole or is there a nut? Frankly, it looks like time to unbolt the mount from the frame and pull the motor to access this problem on the stand.

you have to stare at the photo for awhile to see what it is. As I said earlier, photos like these are hard to work with. A first glance it looks like a hole but stare at it longer and you will see it as a bolt head with a small protrusion on it where a nut was welded on and came loose. I ran into the same kind of photo on another forum and all I could see was a hole but after a while it inverted to a bolt. In fact, it is the same orientation as the example of the type bolt it is. It extends into the block towards the top right.

View media item 98036

 

[evintho]

OK, I see it now. That's freaky! Quite the optical illusion!
Remove everything you can around the area. Get in there with a real 220v welder and weld on a quality nut. Soak it in Kroil or PB Blaster and give it a shot. Good luck!

 

[MoonRise]

Ah, rounded over bolt head. Got it.

Get welder with 'enough' power (240V MIG machine is typically plenty, a 120V cheapo HF unit is typically not enough power) and weld on a nut.

The nut gives you something to turn with a wrench and the intense localized heat from the welding helps to loosen up a stuck/frozen bolt.

It may take more than one weld-and-wrench cycle, but it WILL work.

 

[WhoWhatNow]

It is entirely possible the blot is aluminum even if the replacements are steel. Quite a few of the aluminum bolts on my 07 BMW were discontinued by BMW and replaced with steel versions.

 

[protegeV]

wow, that's trippy. I think we were all looking at it as if the fastener was going in a top/right to bottom/left direction when it is actually the opposite.

 

[Shadowdog500]

Can you get to the bolts that hold the mount to the engine or the bolts that hold the other part of the mount to the frame. I’ve had cases like this before where the easiest solution was to unbolt the mount at another point and take care of the stuck bolt after the engine is out.

 

[Dustball]

I hate photos at angles like that, they look more like a hole than a nut or bolt. If that is a bolt then we are looking at the bolt with the weld that was left when the nut he welded on came off. Napa has sockets for rounded bolts and nuts.

I also nominate the bolt head extractor. Using one with an impact may get it out- push hard as you're reversing it so it'll grab better. The only question is if the bolt head is big enough for the smallest size extractor.

https://www.amazon.com/Tools-Performance-Extractor-8-Piece-1859150/dp/B00LFRUN0O/ref=sr_1_40?crid=13UJ2JE0HHN9G&keywords=irwin+bolt+extractor+set&qid=1572405056&sprefix=irwin+bolt+ex%2Caps%2C230&sr=8-40

 

[kwyjibo]

Coincidentally, I just won a battle with a similar bolt on a BMW. Mine fastens the transmission to the motor. I hammered an etorx socket onto the bolt head instead of using the extractors - I didn't think that the extractor engaged enough of the etorx head. From your photo it looks like you have a relatively straight shot at your bolt. I'd try using the correct size socket (e14?) on an extension and hammer the socket onto the bolt. Only try turning when its seated securely. It's not a problem if you need to add u-joints or wobbles, I ended up using two wobbles and 2' of extension to get to mine. Don't forget to soak with PB Blaster or similar. Also, double check that you're using the right sized socket because it's easy to use the wrong one with external Torx. Good luck.

 

[ChevyEFI]

This was better than the "stare at the picture until you see it" prints sold at the malls ~25 years ago. Well done, Lee.

 

[Bighead38]

I also nominate the bolt head extractor. Using one with an impact may get it out- push hard as you're reversing it so it'll grab better. The only question is if the bolt head is big enough for the smallest size extractor.

https://www.amazon.com/Tools-Performance-Extractor-8-Piece-1859150/dp/B00LFRUN0O/ref=sr_1_40?crid=13UJ2JE0HHN9G&keywords=irwin+bolt+extractor+set&qid=1572405056&sprefix=irwin+bolt+ex%2Caps%2C230&sr=8-40

For really stubborn stuff I have hammered the impact while using a wrench on the bolt extractor at the same time.

 

[upper_tanker]

I love those bolt extractors! They get my vote. I have extensive experience with them because it seems like when our assholes change mower blades, they feel that they have to use the wrong size socket on the spindle bolt.

 

[LeeG]

SGKent,
That is a perfect description of the bolt. I didn’t even see it the other way until it was pointed out here.

View media item 98066
Here is a zoomed in image. The brightness on the left side throws a shadow on the right side of the head giving it the illusion of a hole.

I guess I’ll have to drag some tools and my Miller 211 over to his place and try it. It figures that I just upgraded my 75/25 bottle to a 330cf bottle. It might be a good excuse to get a small bottle for portable use. I’ve also have a few sizes of M18 impacts we can try with an extractor.

Thanks for the input everyone.

Lee

 

[3baygarage]

wow, that's trippy. I think we were all looking at it as if the fastener was going in a top/right to bottom/left direction when it is actually the opposite.

Same here.

 

[Jason280]

Get in there with a real 220v welder and weld on a quality nut.

220v welder wouldn't make any difference in this situation, even a cheap 120v HF welder has enough amperage to weld a nut solidly enough to remove/break the fastener. More than likely, he wasn't able to get a decent enough puddle going...looking at the pic, I am not sure how much room is even there for a MIG gun.

I'd try the bolt head extractors, but nothing about this looks like an enjoyable experience. I think its already been mentioned, but you could also try hammering a 12pt socket in place over the head. Once again, though, I can't tell how much space you have to work with.

Do you know what rounded the head off in the first place? Any chance he used the wrong socket, or is it simply seized in place? If its seized in place, the extractors still may not work. Only option may be welding a nut in place, or grinding off/out the head.

 

[firebirdparts]

I agree. Access is the only problem really. that was what caused the original problem. You can try welding, then the extractors (at least I would in that order) but if you can't get at it, just start taking stuff off.