Apparently the Fail Fairy hasn't quite finished with me yet...

During the reroute process, I decided that rather than using the blockoff plate Bell supplies with their kit to replace the upper half of the thermostat housing, that I'd clean up the engine bay a tad by removing the entire housing and installing a freeze plug.

Things have not gone well.

I was having considerable difficulty driving the plug in straight, so I made a bracket out of some angle iron and used the stock thermostat housing bolts to draw it into the head, pushing the plug in straight. During the process, I snapped one of the bolts. I then drilled it and tried to use a bolt extractor, whereupon that broke off inside the bolt.

Frustrated, I used a small hammer to drive the plug in the rest of the way, which buggered it slightly on the top.

Needless to say, having re-assembled everything and started the car, it's leaking coolant.




I'm feeling that my options are a bit limited at this point.

I don't have a lot of confidence in trying to install another freeze plug, based upon the probable damage I've done to the mating surface. Even if I coated it in JB Weld, I'd expect thermal cycling to eventually cause that to fail.

The remains of the bolt are protruding about 2mm from the surface, and vise-grips have failed to work. Screw extractors are harder than any known drill bit, so drilling the bolt again isn't going to work. As a last resort, I may try slotting it, but it's in there so tight I can't see that working. It's really quite stuck.

My current thought process involves fashioning a plate from thick aluminum stock to cover the freeze plug, and drilling & tapping the head in a couple of 1/4-20 holes inboard and above / below the stuck bolt to secure the plate, in addition to one stock bolt that remains.

Thoughts? Does anybody know what's behind this area, and whether it'd be safe to drill a couple of holes?

 

that sucks man.. Is there any room on the broken bolt to tackweld a new bolt on and then wrench it out?

 

A socket wide enough for the freeze plug to fit inside it, a beefy bolt, and a couple washers.

Drill the freeze plug for the bolt. Put the washers over the bolt and then the bolt through the socket. Tap the freeze plug for the bolt. Place socket/washer/bolt combo over the freeze plug, thread bolt in. Tightening the bolt should pull out the freeze plug. If the plug's stuckness overcomes (or is likely to overcome) the threads you tapped.... maybe add jbweld?

No ideas for removing the broken bolt/extractor combo.

 

Unfortunately, I sold my welder when I left CA, and the car is immobile at the moment.

I just measured the depth of the other hole and compared it to the other bolt. I believe what happened is that I bottomed the bolt that has broken and the continued effort of trying to turn it broke it. Given that, I don't think any amount of force that a couple of tack welds could bear is going to remove it.

I've basically given up on that bolt, and will probably grind it flush and abandon it. The question then becomes how to deal with this hole...

 

Years ago I slathered some RTV around the freeze plug before pushing in in, and it's held.

 

Joe, I'd hardly call that immobile. Worst case, the freeze plug pops out on you and the problem is partially solved.

If you never want to see the plug out again, what about brazing it to the head?

 

irwin makes a nice set of easy outs. Don't know if you ever used them. You can tap a easy out over it and it should wrench it off as long as you have not bugered it up to much. Prioir I would soak it in pb blaster first. freeze plug should be easy to remove and just do what jasonc said and you some rtv. just allow it time to cure before adding coolant.

 

When all else fails, I go to the dremel. Grind a straight slot in the bolt end. Grinder will cut thru bolt and extractor both. Straight screwdriver, with a wrench on it, if possible. Heat the housing, it will help. Stick in the screwdriver, and give it a sharp rap on the end, then back it all out.

Edit: drive out the freeze plug, and stick in another. If it's leaking, it's not fitting right anyway. Clean the housing (lightly sand), and smear with hi-temp RTV. Use a large socket to drive in the new plug. The socket should be as large a one as can fit in the concave side of the plug. I've done this on reconditioned engine blocks a dozen times and never had a leak.

 

Ok, the plug is out and there does not appear to have been much (if any) damage to the mating surface of the head.

Now, to ask the question that got me into all this trouble in the first place- what's the best way to install a freeze plug? Prior to making the bracket that led me to break this damn bolt, I'd tried hammering it in (with a socket whose OD allowed it to just slip inside the plug) and I just couldn't keep the damn thing straight. Granted, all the crack I'd done earlier kinda gave me the shakes, but still...

EDIT: I remember once seeing an expansion plug that was made of rubber, and had a bolt that you tightened to expand it. Whaddya think- too hokey for a permanent install?

 

sucks to be u...

 

I'd install a new freeze plug. Just put it in the freezer for a couple hours prior to fitment.
Don't know what Begi supplies, but make sure you get a 30mm plug.
Although not strictly necessary, I'd use some sealant like Permatex High Tack or so.

 

Yeah, thanks for that. Oh, gee, what's this say in your account? Something about being banned?

Bell supplies a nicely machined plate that you install in place of the stock upper thermostat housing. I decided I wanted the whole thing gone instead.


However, a new plug is in, it (and the housing) were liberally coated with RTV beforehand, and hopefully this'll hold. Surprisingly, this one hammered in quite easily with a large socket. I don't know if the last one was slightly out of tolerance or what, but I simply could not get that damn thing to hammer in straight.

Sucks that I can't drive my car for a while, but alas...

 

If I remember correctly, freeze plug holes have a chamfer to them so there is more sealing surface when the plug is seated.

 

I've heard of folks popping these out on track, FYI. I have a freeze plug but I won't be using it.

 

ok u win...

 

I used a block off plate over top of the freeze plug because I knew if I did just the freeze plug it would leak.

I used a **** ton of RTV before mine went in, and then went around the edge like chalk.



You can see all the gray RTV in my pic. It also went in on an angle, that bothered me.

I've seen the rubber plugs, they just expand as the bolt is tightened, probably works just as well. you can more than likely drill the freeze plug in the middle until your relieved enough pressure and you can pull it out.

 

I wouldn't worry about it. There's lots of them in the engine already. There's 4 of them on the exhaust side alone.

 

Installed by the factory. Is the hole in the head freeze-plugged from the factory on the 323?

 

I believe so. Should have a pic somewhere.

 

I ruined a freeze plug trying to tap it in. Bent it out of shape. The second one went in easier and has held without any leak for over 4,000 miles now. Joe, that plate begi sent, can it be used directly on the head?
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