help with stuck Vanos 8mm hex caps

[Russianblue]

I'm doing an 'experimental' head gasket change on my kids old 200k Xer. It overheated slightly in January (failed 1 year old OE expansion tank) and has been losing coolant very slowly, until recently, and it will overheat now almost as soon as it gets to temp. no leaks : ) water pump, radiator, T-Stat, entire cooling system has less than 10k miles.

I've been watching 50sKid and ShoplifeTV and I'v got the valve cover off, the intake is removed and I was well on my way.

Then I went to loosen the 8mm hex caps on the vanos unit and they aren't going ANYWHERE. Even with an 18" breaker bar. I felt the hex give a tiny amount and I stopped immediately. it probably stripped the holes about 1/64 inch. There's a TINY amount of slack but it WILL strip if I apply any more force. I know it will.

Mind you, it's not stripped YET. I can still put probably 40 ft lbs to it before it even starts to make me worried. but that's not enough.

If anybody has any ideas on how I might be able to get these things out, I'd appreciate it. I'm willing to use a dremel or drill if need be. I imagine you can come by these vanos cap replacements fairly cheap. I just need to go ahead and get this head off so I can see if this thing is worth salvaging.

thanks!

[X5chemist]

Have you used any kind of penetrating spray? Since the oil will be changed, spray it heavily. The other option is heat. A small torch will work. The seals will have to be replaced. I've used heat on broken bolts. Works ever better if you can put a vice grip on on the bolt. Once it's hot, use the vice grip to move it back and forth. However, I think the vanos bolts are sunk in.

With all the coolant out, replace the o-rings where possible. You can buy a whole kit of orings. I keep a bag of coolant o-rings in the trunk.

I'm curious though. Would one be counter threaded?

[lo_jack]

Are you talking about the ones under the little caps that pull out? The ones on the actual VANOS you need to take out to put the new seals on them?


if so, those are reverse threaded. make sure its not that, if so.

[oldskewel]

I'm also not clear on what ones you're talking about.

The screws on the ends of the VANOS cups are left hand thread. But I think they're Torx, not hex.

Good luck with the project.

[cn90]

I think the O.P. referred to the cap with 8-mm hex:

Beisan Systems - Procedures - Double Vanos Procedure

EXCERPT:
...Remove 2 vanos cylinder front cover bolts w /washers.
Cover AC belt and lower radiator hose to protect from oil leakage (towels).
Initially break bolt seize (tough), then place oil container below bolt and unscrew bolt (8mm hex bit socket 3/8” / 3/8” long-arm ratchet & extension).
Engine oil will leak out from vanos cylinders. A significant amount will leak out from exhaust cylinder.
Stuff vanos cylinders with cloth to extract engine oil (towels).
Clean up oil spills, especially from belts and pulleys.

[andrewwynn]

To unstick a seized bolt like this (best example is vanos t55) you need to hit it firmly on the end of the bolt (as if it were a nail).

I recently twisted the head off two e12 m10 hardened bolts so I feel your pain. With a pin point torch you can heat just the bolt to make it longer and release tension on the threads

[Russianblue]

here is the part in question:

https://youtu.be/6bmYj5ZOAz4?t=329

https://www.fcpeuro.com/products/bmw...ug-11361438338

The T30 torx screw is underneath this cap and that one IS reverse thread. This is standard thread.

I tried a bit of heat, but firing that MAPP gas with all that oil and fuel residue made me a bit leery. I previously tried some penetrating lube but wasn't sure that was doing much good given all the oil that area is exposed to already. In retrospect it did nothing.

I then read about the dremel and chisel method. I cut a slot at about 9 oclock on the cap with a dremel disk and got a screwdriver in there and started banging it straight down. Nothing doing.

After mauling the cap and making zero progress I reasoned that these caps are going to have to be replaced regardless. Moreover, the replacement caps are cheap. Anyway before I resorted to drilling/cutting the entire thing I figured I'd at least go ahead and give the breaker bar all she had until the hex bit stripped out the hole.

Well, I suppose I got lucky. All I will say is that it took what had to be upwards of 100 ft lbs of torque to snap those things loose. I had two hands on it and pulling damn near as hard as I could. No lie. It takes less pressure to loosen my wheel lugs. This was an 18 inch breaker bar/extended socket.

After a deafening SNAP!, both sides came loose. My hex bit was buried so deep in the metal that I had to put the cap in a vice to hold it and reverse ratchet the hex bit out. No way those same parts are going back in.

Mind you, i'd rebuilt this VANOS about 2.5 years ago and torqued those caps myself. I was meticulous with the torque values. My hunch is that the oil that got under those caps when I changed it may not have been there from the factory and varnished up with the heat of the cyl head. When I reinstall, I am going to clean the hell out of those mating surfaces first. I don't think the threads were seized. I think the washer was frozen to the surface with gummy baked oil/varnish. Just a theory. Could be completely incorrect.

[andrewwynn]

What you describe is similar to the situation with the cam locking bolts.

It took no time to fuse. I had to redo the timing and within 1-2 days it took close to double the torque I set them with to loosen.

Hitting with a hammer first dropped the torque needed about 30%

Good you got them out, knowing you couldn't lose gave you the knowledge you could use as much torque as needed. I'm wondering if anti seize can be used when installing to make removal reasonable.

[X5chemist]

Good information. Eventually, I'll have to do mine too. If there is enough room, I'll use a manual impact. A few strokes might break it loose. Plus only if there is enough room to hit it straight on.

[Russianblue]

I was wondering the same (about the anti-seize). I don't think it would hurt.

It'd need to be able to withstand that relatively harsh environment. I don't think it would take a ton.

Again, my hunch is that the stuck part is bolt flange and the washer rather than the threads.

Interestingly, the t30 reverse thread torx bolts came out with zero issues.

i was not able to fit my little milwaukee M12 impact drill.


I've gotta come up with a decision matrix for this car and whether to continue moving forward with a repair. I will probably be hitting up the board for info here shortly.

My E12 socket arrives today. Within the next couple of days I should know if the head is salvageable or headed to Make a Wish.

I only need it to last for about 2 more months so my kid can beat around town until she heads to college.

If I can get it fixed for $500-$750 and it lasts another 6-12 months, that's just a bonus. I might stretch to $1000 or so but she and her friends have beat the living hell out of it.

Obviously that means I do all the labor. There's no ability cover a timesert kit in that budget. $79 engine support from Harbor Fright. Head gasket. Head bolts. VANOS hex covers. Valve cover gasket. Coolant. Oil. some new Vacuum tubing...and i think i found a leaky injector.

still within budget at that point and still haven't even serviced the head.

i'm not sure how many warped heads get skimmed and go right back on without seeing associated block-thread damage. it's pretty rare. so the likelihood of getting out of this for my budget is not particularly good!

that budget number is arbitrary. it's maybe half the value of the car in good health.