Noticed a damp spot under my 85 Z51 today. After checking I found it was the thermostat housing gasket. Of course one of the bolts snapped. Seems like corrosion from steel to aluminum contact. Looking for any advice to avoid removing the intake. Removing the plenum is about as far as I want to take it. Have about a quarter inch exposed with good threads. I have some ideas other than helicoil. Wondering what you can offer. TIA.

Thanks for looking,

Joe K
ETA: system has been flushed numerous times, still seeing rust. Funny what I drained was green as grass.

 

Try welding a nut onto the stud. Ive done that with exhaust bolts on aluminum heads with good success.

 

I would heat the AL with a Micro Torch ( Harbor FRT) and hit it with CRC Freeze-off. Hit the bolt with a brass bunch and repeat the heat cycle - freeze-off . I would do it a few times and use 2 thin nuts jammed together on the stud to take it out.

Use FREEZER Aluminum foil to block the heat from other parts. (it's thicker)

Last case is to drill and tap. Likely one bolt size larger.

 

You could also go to Autozone or O'Reilly's and get an EasyOut. Soak the bolt in PB Blaster first (a lot), drill an appropriately sized hole into the bolt shard, and use the EasyOut tool to crank the bolt remains out of there.

 

This works. It works every time. Heat works, welding a nut on, to give you soemthing to to turn it with, also works. Earlier tonight, I removed 4 broken off exhaust manifold bolts from a Chevy truck at work, with aluminum heads. I welded nuts on all of 'em, and then threaded them out of the heads. It works.


If you don't have access to a welder, giver 'er hell with a pair of vice grips, and HEAT the intake around the bolt hole, with a propane torch. HEAT it. HEAT works. Use HEAT and the bolt will come out. HEAT.

 

Yeah but, what about HEAT?

 

Thanks everyone for all of the great ideas. Think I'm going with HEAT, lol. Going to try the CRC Freeze Off and the double nut. No one had a mini torch or the CRC in stock close so I just had O'Reilys order them for me. Not in any hurry so I'm just going to take my time and really do everything I can to get the stub out.

Joe K

 

Right?

Guys dick around will all manners of crap; PB blaster, Kroil, Candle wax, MM oil, ATF (EDIT: CRC Freeze Off)....none of the stuff does much or anything IMO....plus you need to wait. So you soak (the outside of) it, try it the next day? Maybe it works...probably not. You've wasted a day.

So, I tell folks to use heat. Blast the **** out of it with heat because heat always works....and it works right now. not tomorrow, not in a week, Now. But, they don't "get it"...they aren't sure, they think that maybe they should use potions. Take their time. Taking more time, doesn't help. It's not "safer". It's just.....slower. I do this stuff for a living. I get paid salary, so the sooner I get this crap done?....the sooner I can GTF out of work and/or move on to better things. Last night I had dinner plans and was working on those broken-off exh manifold studs in the aluminum heads. Did I waste time with potions? HELL NO. I busted out the welder, got all 4 broken off studs out (even the ones broken off, down in the holes) in ~1/2 hour....and got the F out of work and to my dinner date on time. HEAT. Heat works.


.

 

Stay away from the EZ outs. If it is rusted that tight that it snapped the bolt, an EZ out will be as useless as women at a gay bar. Snap the EZ out off in the bolt - now you do have problems.

 

 

Hey Tom. Do you think heat would be a good idea?

 

Exactly.
Anyone that has been waiting in the shop getting they're exhaust maniflod gasket (or similar) changed won't hear from the mechanic that "we'll have to wait until the PB Blaster works"

 

 

Won't be getting to this until Monday. I'll update then. I'll be using HEAT, in case it wasn't mentioned.

Thanks,

Joe K

 

Ha. Yes, agree on heat. If you have a mig welder that's be awesome. If it is a fluxcore welder, use a pile of tin foil and spend the time to wrap and protect everything. it splatters and leaves a dusty brownish residue.

either way, im sure you will remove all the electronics like that injector and the vac lines and again...use multi layers of tin foil to protect everything from the heat.

i have had very very very good luck using heat plus these things. i would get the size that is just a smidge too small, and pound it on. it will bring it out.


but never ever ever do i use the punch took + drill method unless everything else has failed.

back in 2014 when i joined the forum and had my first project, an 85 z51, i learned the "bad day" that broken studs and bolts can cause. since then, with the help of this forum, I have become Ninja at removing them to the point where it doesn't even phase me anymore. also, if you really need it, a wonderfully more "powerful" penetrating fluid is acetone + atf, but you also need the little oil squirt can. and the acetone eventually destroys the internal pump in the little can. i went through 2 oiling cans and quit using it. but if i was seriously in a bind, i would mix up some of that. for now i use pbblaster or kroil etc. along with excessive HEAT.

:-)

keep us posted. Your car is one my personal favs here. I love the BLUE early cars.

 

Appreciate the advice and compliment VikingTrad3r. Fortunately it's not the Blue Corvette its my Gray Z51.

Joe K

 

Well I just don't have a torch that is going to be sufficiently to it up. Probably going to install a helicoil. In the mean time I managed to break a switch/sensor and I'm not sure which type it is. Check my FSM but still can't figure it out. It's the one in front directly under the throttle coolant hose fitting. 3/4 diameter, 2 wire. Here's a couple of pics.

TIA
Joe K

 

joe thats the coolant temp sensor. cheap.


i strongly, STRONGLY, STTTRROOONNGGLLYYY advise that you find a guy with a mig welder to come weld a nut onto the stud.

dont drill it and heli it. $50 and im sure there is a guy local who will do that for you.

 

Not sure if I have enough stud to weld anything too. I'm going to check with the car club I'm in Wednesday.

Thanks!

Joe K