how to render a perfectly good thermostat useless
 

I was removing the oil lines from the thermostat and 3 of the 4 came out without stripping the threads. They'd been soaking for a week in PB Blaster. The 4th wouldn't budge so I put the thermostat in a vice and went at it one more time when I heard a loud crack as I flew backwards. Looks like I'll need a new thermostat and engine to thermostat oil line.

http://img87.imageshack.us/img87/2540/img0120vl0.jpg

Crap! I hate it when that happens!
No injuries? (other than the broken stat)

That's the kind of stuff I fear!!!

Was any heat processes used?

Best,

No injuries but at one point I was pulling so hard I thought my previously broken collar bone was going to break again.
The first 3 were pretty tough but they all came off leaving the thermostat threads intact. The "block" that you use your second wrench on for this line is smaller than the one for the others and the wrench was slipping so that's why I put it in the vice. No heat was used, probably should have but I can't say I ever imagined the housing would just rip apart like that. Oh well. Anyone got a thermostat laying around? And an engine to thermostat oil line?

I did the same thing while replacing some lines.....not terribly expensive to buy a new one, but aggravating. After I completely cleaned and degreased the broken thermostat, I progressively cut it on my buffing wheel with finer and finer polish and rouge until it looked like it had been chromed. Then I found a wooden trophy-type base, stained and varnished the base and then mounted the beautiful polished thermostat. I put more effort into this project than the oil lines that I was replacing.

Steve

:) I broke my AC condensor mounting bracket in a similar fashion. Sucks...

Ouch. With a Dremmel tool, you might still be able to salvage the line, but it also might just be best to start with new stuff...

-Wayne

Pics?

Nice break! http://forums.pelicanparts.com/support/smileys/wat6.gif

Your story of the thermostat in the vice reminded me of destroying mine in a similar way, while trying to get one of the long hard lines loose. I had tried lots of heat and PB-Blaster, with no luck. So I wrestled the whole mess out of the car, put the t-stat in the bench vise with the line sticking 6 feet out into the garage, and used the hard line (which I was going to replace anyway) as the lever arm to break the joint loose. What happened was that the line came off and took all of the aluminum threads with it. I had no confidence that the "thermostat thread saver" attachments would work on what was left, so I junked the thermostat.

I was picturing what would happen if the vice broke off the bench and came flying back at me. Nothing like applying a lot of force and then slowly beginning to realize that it's probably a bad idea.

Good luck
Scott

I consider $400 fairly expensive ... but at least it's available for purchase.
:)

The best way to tackle these thermostats seems to be with sharp blows on the wrench. Heat doesn't seem to be a good idea with these. Here's why I think that:

The collar nut on the oil line is steel, the t-stat is alloy. The alloy likely has a higher rate of thermal expansion. So I believe heat is actually expanding the alloy more than the steel and making the connection tighter. The key would be to apply heat sparingly so it only heats the nut. But alloy is a good heat sink so isolating heat to the nut only is not likely.

The internals of the t-stat have wax components. Heat it too much and you'll compromise the operation of the t-stat- it may be stuck closed or open (mine's stuck open).

I've also tried cutting the line and putting a deep impact socket on the nut. That was disastrous. Broke the t-stat just like the picture above.

I can't stress enough to anyone working on these, if you're fortunate to get the lines disconnected cleanly from the t-stat? Be sure to use antiseize paste on the threads and the shoulder of the compression fitting (where the nut contacts it) upon reassembly!!!! A lot of times the line gets corrosion on it and does not let the nut spin freely. I occasionally loosen my t-stat nuts to avoid the freezing of the nut on the line.

KTL: good advice as to the internals of the thermostat...never knew this. THANKS!!!

Best,

I'm currently batting 1.000 on the last two times I've had to do this. That means the next one I have to do in the next couple weeks, I'm overdue for breakage or strippage. I've had good luck spraying penetrant into the threads and then heat cycling them for several days. Then comes the big hammer. Those compression fittings are nutted down incredibly tight, at least they are once that corrosion builds up. If you have a good local hose shop that can get metric fittings & parts, though, the best thing to do is to just dremel off the nut. Works like a charm and zero risk of damage to the threads if you have a steady hand with the cutoff wheel. Wayyyy faster too.

I would've done that except the line that wouldn't come off was going to be reused. The crimped line I was replacing came off fine.


http://forums.pelicanparts.com/uploa...1202499572.jpg

Youch!!! That's crimped but good! My advice was just 'in general'.

I had a set of lines a few years ago that I just tossed right in the trash. Both hoses were literally crushed flat for 4". Totally unsalveageable. How the heck does that happen???

Y'all seen some of the trick thru-the-rocker installs? No more crushed lines...

When I was a mechanic, the best soloution that I found for removing the pipes from the thermostat was to cut a slot in the nut with a die grinder or dremmel tool. You need to use care not to cut too deeply. In most cases I did not even cut all the way through it. I then uesed a large screwdriver to expand the nut. This is done by inserting the screwdriver into the freshly cut slot and twisting it.

The expanded nut then turns off of the thermostat without damaging the threads. The down side of this fix is that you need to replace the oil line with a new one, however, if it was stuck on there that badly...you probably should replace the line anyway (deterioration of the rubber hose section, leaking at the clamp, etc.). The upside is that you get to save the thermostat which is way more expensive and rarely requires replacement. Another benifit is that you get to admire the nice new annodized oil line...it looks so pretty! :-)

I came to use this method by bad experience after bad experience. I tried PB Blaster, heat alone, heat & cold, busted knuckles, etc. I have witnessed other mechanics deal with this issue...some of their efforts resulted in damaged body work, melted trim, melted undercoating, small fires, a broken finger and even a hernia. Trying to save the line (if it doesn't come off easily) wastes a lot of time too. If your time is worth money, your best bet is to sacrifice the oil line for the sake of the thermostat, your car and your sanity.

FC

I think it was $250ish? wasn't it steve? but still not pocket change

I agree with FC. I'm no mechanic but i've seen many of my local friends and alot of people on this forum mess with these oil lines because they want to save them. It's not worth it if you can buy the replacement line as easily as we can these days. Even though Porsche is starting to reduce their supply of replacement parts for these cars, I think aftermarket sources like SSF and the like will continue to supply these things.

mb911,

I was mainly referring to the oil line that comes from the engine to the thermostat or the one that goes from the thermostat back to the tank (soft lines or at least partially soft) with regards to the expanded nut fix. When replacing the hard lines (no rubber part) that go to/from the thermostat and the front cooler, the fix I recommended may not be the best fix depends on the condition of the lines. I guess I would ask why remove a line unless it is damaged. I know sometimes you need to remove one to have good access to the one you want to remove.

Even still, is the cost of the hard line worth the expense of the themostat and a hard line when you bust both trying to remove it? Philisopical question for those much smarter than I?

FC

When Comin In Hot and I broke his two years ago, it cost us $340 thru Motodelta. I don't think they've gotten any cheaper.

Funny you mention that. I'm currently going through this myself and I have 3 of the 4 lines free. Heat cycling with PB-blaster and the t-stat in a vise.

Wrench doesn't like the impact of a mallet.

http://members.rennlist.com/jpinkert/brokenwrench.JPG

I now have a new wrench on the way from Pelican.

I had some success today! Since december (as the weather sucks) I've been spending 15 minutes each weekend soaking the connections, torching them a bit, re-soaking, and hitting with a hammer (or punch for the not-so-easy-access one). Thermostat is still in the car.

I got the 2 "easy access" ones (one soft line towards rear, one hard line towards front) to budge a wee using a big monkeywrench, hand pressure, and a 32oz hammer on the wrench. And I got the difficult access one going to the front to budge using a pipe wrench and a breaker bar. Neither tool fits the other rear connection, so I need to invest in a 36mm wrench I guess (or take the other rear line off first). Haven't undone anything yet - too damn cold. Just moved 1/8 turn. Plus, I want some more PB Blaster soaking in first.

I am imagining that the 0 degree temps have helped with my efforts ... Al does have a greater coefficient of thermal expansion than Fe... or it's just coincidence and the continuous soaking, heating and hammering.

So, has anyone ever tried dry ice on the T-stat? Just curious ...

Yeah, Ben.....I think that the cost of the thermostat (at that time, anyway) was about $250-$275. I'm in the middle of a basement remodeling project and I've got my "trophy" tucked away. I'll post some pics when the dust clears.

Steve

Oil Lines/Thermostat..................
 

I removed my oil lines and thermostat a couple of years ago. I discovered that the oil line nuts were stuck just as you described. Thinking that a sharp blow would be more effective than a lot of torque, I made this wrench. It is mild steel, 1/2" thick and was cut out using a hack saw and a dremel.

http://forums.pelicanparts.com/uploa...1202697184.jpg

http://forums.pelicanparts.com/uploa...1202697274.jpg

The mass of the wrench allowed solid blows from a dead blow hammer to successfully break all of the lines loose without damaging the thermostat. Oh, yes, I held the thermostat in the jaws of a 4 foot long cast iron pipe wrench that I just happened to have lying about!

I did my first track event this weekend since replacing my thermostat and crimped oil line and I'm sorry to say it didn't help my temps at all. I have the 28 tube brass cooler and just driving to the track on Friday sent it near 210 and after 20 minutes on track it was approaching 250 at which point I came in. Outside temps were in the 50s and 60s so I can't imagine what it would do on a 90 degree summer day.
After having people here and on Rennlist tell me they run brass coolers on track with cool temps in hot weather I'm starting to think my gauge could be reading high or my oil temp sensor is not working correctly.
If that doesn't solve it I may look for a used Carrera cooler and fan. My friend with an 87 couldn't even hit 210 after a 20 minute session going to redline for every shift.

I assume you felt the lines to make sure they were hot and therefore the thermostat was opening correctly? You shouldn't see those kinda temps while just driving to the track with outside temps that cool. The thermostat is supposed to open at 180.

Yes the lines and cooler get very hot. Bad on-engine thermostat?

I wonder if one was to use a liquid gas to freeze the threaded housing portion, then while it is at -190 degrees F, then apply heat to the nut, but only enough to get the fitting hot, so only it has time to expand from the heat application. Then attack with the wrench to loosen. Does anyone think that this would work? Tony.

Our host sells them for $445 OUCH but the also has an aftermarket MOCAL one for $131, I am not sure if the MOCAL one can be used in place of the factory one or not, Anyone?????

The factory one has a built in pressure relief valve apparently important when starting a warm/hot car. Grady gave me an explanation a while back...I'm sure its been posted before. On the other hand, my '72 has a mocal thermostat w/ aeroquip lines and I have yet to have any issues. If you were to go the mocal route with all factory lines, you'll need to get all the correct 30mm to AN-12 adapters ($30 each + elbows, etc).

Have you checked the on-engine thermostat for proper operation? Remember you engine has two oil coolers.

Ninesixfour,
I had the same temp problem with my 80SC, turned out to be that i mounted by sump plate and cover off a 1/4 turn and it was not letting the oil flow right. It was ok on the streets but when i pushed it on the track it almost got to 250 before my first session.
Never had heat issue before or since, sounds simple but that was all it was, my own stupidity. Sorry about the oil line and thermo. my did the same thing, that "special" wrench is worthless.

Hmmm....I did change the oil sump plate gasket during this adventure so it's certainly possible I installed it incorrectly. I didn't know there was an exact way it had to be mounted.

No I haven't done this. According to my research a partial engine drop is required to gain access?

Chuck I've read through the dual cooler installation at Elephant several times. I know 2 coolers would solve my problems (especially for a track car) and I can do without the windshield washer reservoir but I haven't seen a good solution yet for relocating the emissions canister. Any info you or anyone else has along with pictures would be greatly appreciated.
I know a monster Setrab/Mocal/B&B mounted behind an IROC bumper would also solve things but I wasn't planning on doing the bumpers just yet.

I went for a drive and got the oil up to around 230. Came home and crawled under the car to feel the engine cooler and it was very hot as was the line coming from the oil tank to the cooler. Could the heat exchanger make them that hot or is it safe to say the cooler's getting oil?

It should be too hot touch, finger buring hot.

Sometimes the fins get dirty, caked with oil and gunk. This prevents the fan from blowing through the cooler. Thus it gets hot, but it doesn't cool the oil. Check the botom of the cooler for gunk, then pull the cover off the top side of the cooler and see if it's clean.