We all have this love hate relationship with our cars and right now the hate is coming out.

So I narrowed my heating issues down to a bad thermostat. The car's got a little over 60K miles on the original engine. And runs well except for a little boost issue (7-5-7 pattern). I go in to replace the thermo and as I'm taking pieces apart I notice one of my check valves is damaged and disconnected, most likely this was causing the boost issue. Luckily I ordered some check valves from Dale and replaced it. Thanks Dale. Back to replacing the thermo. I start to take the housing off and, "snap" the lower bolt breaks. Lots of bad things begin to shoot out of mouth. Ok whatever, I'll worry about it later on to the next bolt. "Snap" ok this sucks. Two of the three bolts broke but I got the housing off The thermostat was shot to hell so I pulled that mother out. Now I have to deal with the bolts. One's got about 3/4-1" of the thread sticking out the other has about nothing. I used vise grips on the one but couldn't get it out. I'm thinking of spraying some PB blaster on it and let it sit then try again. For the other one I was thinking of using a screw extractor (easy out) to get it out maybe tap it. I figure this is the only thing I can do at this point. Anybody have any secret tricks I could try. I should be getting a digital camera today so I'll take pictures of my progress.

 

One trick I've used successfully is to tap the end of the bolt (along its axis) with a hammer. This sometimes will break up the corrosion holding the bolt in place. Use this in conjunction with penetrating oil and gently-applied heat. Be patient and repeat the application of all of the above several times. Then use your vise-grips and/or an awl to work the bolt out.

Be careful with screw extractors - in this small size they are too easy to break off, and then you've got that hardened piece stuck in the hole!

The last resort is to drill the bolt out. This usually leads to having to "Heli-Coil" the holes to restore useable threads.

 

I have a stud extractor that I ended up buying to remove a stuck manifold stud (one that goes into the housing). They work great. Sears has nice ones, harbor freight (if you have one in your area) has more variety but they are cheap chinese stuff. A drill-type extractor will probably work; PB blaster certainly can't hurt. The kind I have looks like this:

 

Thanks Dave and broken93 for the suggestions and tips. I'll try them out. I really apreciate it.

 

pic

 

Your best bet will be the screw extractors....

 

I noticed the corrosion in the recess for the thermostat gasket. Coolant was probably leaking out around the gasket, and that accounts for the corrosion that locked your bolts in. Make sure that is all cleaned out and smoothed before reassembly, or you risk having another leak. I had to R&R my (original, never previously removed) thermostat just because of a small leak (I was lucky - no problem getting my bolts out) that resulted from a MUCH smaller amount of corrosion than I see there.

 

Another thought...

If you do wind up using screw extractors, try to find some that have a shoulder to limit how far the extractor can enter the bolt. That type may work better for any bolt that is broken off near or below the surface. The ones without a shoulder usually continue to dig in and expand the bolt, making it harder to get out of the hole.

 

Thanks for the tip Dave. And I will surely clean off all the corrosion before reinstallation.

 

tapping the stud thats sticking out certainly should help. On the other hand the other one...

 

Also, you might use anti-seize on any bolt going into aluminum. Anti-seize has nothing to do with hurting torque specs, so don't worry about that possibly making the bolt "come loose". The problem with aluminum is that any moisture that gets into the socket, can cause rust (which makes removing that bolt later a LOT tougher, or cause it to break).

 

Another great tip, thanks Mahjik. You guys are awesome with the helpful tips.

 

i had the adzact same thing happen to me when I replaced the thermostat, I had 1 bolt break half way out, so I took the risk and drilled it through and it desintergrated, I then just retapped the bolt hole and it worked ( phew!) I tell you what though, I was sooo close to crying when it first happened.


I think this also highlights the importance of a bad or leaky thermostat, I think its because of the leak you get the bolt desintergrating problem.

 

WHile you're in there, might as well replace the water pump.

 

Left hand drill bits are available at machine shop supply houses such as J&L and have never failed me yet.

 

if things get really fked up, remember you can always use a helicoil...

oh yeah, since your in there and have it apart and you got the extra thermostat handy, why not cutup the stocker. just for ***** and giggles; gut it, replace and find out how much of a difference it makes if any at all. some say it should not make a difference after the long warm up, some say it will never warm up. you have a chance to find out first hand. personnaly when i gutted my thermostat, i found that i could never really warm up to 180 unless i started to drive very hard, then it would get up to temp and stay at temp, never going over 200 degrees. if by chance you dont need to warm up so fast, having a gutted thermostat means it never being able to fail on you. when my thermostat died on me, it damn near killed my engine and left me stranded. something i never want to go thru again.