Thermostat Housing removal

[azndeugene]

Im working on an 86 325. The 3 bolts to the thermostat outlet sheared. Attempted to extract but caught the threads so I decided to try and remove and replace the entire thermostat housing since I do not currently own a tap to drill out the outlet and retap it.

My question is, is there more to removing the entire housing than just undoing the 2 nuts located on the back side of the housing? I have looked at RealOEM and googled it to see some articles say the fuel rail has to be lifted but I do not see why the fuel rail needs to be lifted to allow the thermostat housing to come off. The housing doesnt seem to budge which is why Im scouring the forums

[noid]

With the hoses removed and the two nuts on the block removed, the housing will slide off the studs (might have to tap it to dislodge any corrosion bonding). The fuel rail doesnt need to come completely off but you do need to remove the two 10mm bolts towards the front of the rail, which will allow you to lift it enough to clear the thermostat housing.

[azndeugene]

Ok so Ill need to knock it harder then cause I took some whacks at it with a BFH but the engine is super sludgy and some parts were corroded so maybe that stuff is just really holding it on there more than i expect.

It seems like itll clear the fuel rail but as long as I can get it to wiggle first to tell me it'll come off then Ill take care of the fuel rail. Thanks!

[azndeugene]

So im wondering if anyone can grace me with their wisdom: the thermo housing still doesnt want to come off. Ive literally wacked it with a BFH/hammer and wood to try and shock it free but to no prevail. It seems like the bolts/housing have fused via corrosion cause when you hit the housing or try to wiggle it, the bolts will wiggle with it too. Ive got about an 1/8" gap between the housing and motor head but that is it. It still will not budge. Im currently figuring a way to take a torch into that area to thermal cycle the bolts but it will be difficult without melting anything.

Any tips/trick/ideas to break this son of a b**** free would be graciously accepted!

[Seawolf]

Lots of PB Blaster fired into the stud/housing hole is needed probably, then double nut the 2 studs that run through the housing to get them out - e.g. screw 2 nuts on to the stud and lock them together tight, use a wrench on the inner nut to wind the stud out. You should be able to whack the housing off with a length of hardwood and your BFH once the studs are out.

Don't hit that housing hard with the studs in place, you'll damage the thread in the head. If the studs are corroded badly - replace them.

[Kershaw]

if you have a space between the head and the housing, put a pry bar in there and see if you can wiggle it more.

post a pic too.

[azndeugene]

if you have a space between the head and the housing, put a pry bar in there and see if you can wiggle it more.

post a pic too.

Here's some pics as requested:
IMG_20160207_202600514 by Eugene Doyle, on Flickr
IMG_20160207_202616568 by Eugene Doyle, on Flickr
IMG_20160207_202651383 by Eugene Doyle, on Flickr

I've tried a pry bar and it still doesn't want to move. I've put even gone a little crazy with a hammer and pry bar in a short state of anger.

I still need to try the double nut method and possibly thermal cycling it

[Kershaw]

There are stud removers, that may help in the cramped space. They look like a 10mm socket that slips over the stud. I'd try that.

Can you pry at it from all angles? Not just the top?

[noid]

If you are replacing the housing anyways, then just cut it up piece by piece with a dremel. Its soft aluminium should get it all taken care of quickly.

[GMAN327]

If it comes free and slides remove the 10 mm fuelrail bolts push rail up out of way will be tight but will go but need to remove the sensor in the housing the large one if left in it will hit the fuel rail and not come off to tall. I just did this sunday. Sorry for caps not yelling just old guy who sees better this way.lol. Good lock

[azndeugene]

So I finally got the thing off but things did not go well at all. Autozone had stud removal tools for rental which were super nifty for the bottom bolt. Its pretty a 1/2" socket with some rollers inside that grip the stud and remove it. The threads are f***ed but idc, they can be replaced.

However, these sockets are fairly large and could not fit in the tight space for the top stud. I proceeded to try wiggling the thermostat to see if I couldn't wiggle the housing off but then the stud snapped leaving half of it inside the head :(

I tried using an easy out and it also snapped inside...I currently feel SOL.

The bolt is parallel with the block so theres no excess stud protruding out for me to grip.

Im wondering if any of you know if its possible to weld to an M8 size bolt without welding to the block? I have a friend who's dad has been a ship welder for years and I could probably ask for his skill to weld but I'd like to poll if its even possible to do so cause then I'd just weld a new stud to the old stud and use the stud removal tool to take the SOB out

[Andy.B]

The thermostat bolts to the head, which is aluminum, so no worry about accidentally welding a nut to the broken stud AND the head.

I would try to cut a notch into the stud with a dremel or cut off tool, and then see if you can get it out with a screw driver. Soak it in penetrating oil, and then give the screwdriver a few whacks with a hammer to shock it loose.

I've never had luck with a bolt extractor, but have managed to get plenty of stuck/snapped hardware apart.

I would highly recommend an impact screwdriver with the above method:

http://m.craftsman.com/craftsman-impact-driver/p-00947641000P

[azndeugene]

The thermostat bolts to the head, which is aluminum, so no worry about accidentally welding a nut to the broken stud AND the head.

I would try to cut a notch into the stud with a dremel or cut off tool, and then see if you can get it out with a screw driver. Soak it in penetrating oil, and then give the screwdriver a few whacks with a hammer to shock it loose.

I've never had luck with a bolt extractor, but have managed to get plenty of stuck/snapped hardware apart.

I would highly recommend an impact screwdriver with the above method:
http://m.craftsman.com/craftsman-imp...p-00947641000P

Can you elaborate on the not welding a nut to the bolt AND head? I have some materials knowledge but no welding experience which is why I would ask for help. I assume they don't weld because the filler metal would weld the nut and stud together before welding to the head since the aluminum can transfer the heat better than the carbon steel can?

I will probably grab one of those impact screwdrivers for the sake of having one for a rainy day. Thanks for that suggestion too!

[nando]

aluminum doesn't weld to steel. that's why you don't have to worry. :)

[ForcedFirebird]

Lay a nut on what's left of the stud and have your friend weld through it to the top of the stud. Then you can wrench it out.