Thermostat questions Options

[dbgriffith75]

Okay, so original thermostats are pretty damn hard to find. No luck yet, and I'm betting that even if I do find one it's going to be a pricey little item. One guy I've talked to has told me that with the way the 914 engine is designed, the flaps will stay open without a thermostat and I should be okay running without it. That's all well and good, but I'm on a mission to keep this car as original as possible.

The Haynes manual said to immerse the 'stat in 70 degree water and it should expand, thus confirming that it's working OK. So I tried that, and nothing. So then I tried immersing it in scalding hot water, and still nothing. But just this morning, I tried my own experiment- I used my soldering torch on it. After about 10 seconds, expansion was confirmed... twice. I'm wondering if maybe it just needed heat like that to break loose after so many years of sitting.

But I'm also curious- is there something significant about 70 degrees? Is that the point at which the 'stat should begin opening the flaps? Or should I just take the fact that the 'stat expanded under torch heat as a sign that it's in operational condition? Thanks.

[2-OH!]

Alot of times, the Thermostat will be cracked down in the bellows portion and you really have to look to see the cracks...A good way to know if it's cracked or not is to submerge it in water...Bubbles are not good...Does it shake and hear water inside, not good...

Heating it with a torch would move it regardless due to expansion of the metal, but just motor heat won't work that way...It needs to be sealed to work...

I have heard that V.W still sells them for the Bus...The expansion rate should be the same...

If you are worried about originality, you can still use it, it just will not open the flaps...Where you live, if you don't drive it in the winter, just leave the flaps to the normal position and you will be just fine...Motor takes longer to heat up but in your climate, it won't overheat...

2-OH!

[MrKona]

Here's a really good link about thermostats explained.

[type47]

there is also a way to fit/adapt a type I thermostat to a type IV motor. type I thermostats are still available. opening temp is slightly different but don't think/know if that makes any difference.

[warrenoliver]

Okay, so original thermostats are pretty damn hard to find. No luck yet, and I'm betting that even if I do find one it's going to be a pricey little item. One guy I've talked to has told me that with the way the 914 engine is designed, the flaps will stay open without a thermostat and I should be okay running without it. That's all well and good, but I'm on a mission to keep this car as original as possible.

The Haynes manual said to immerse the 'stat in 70 degree water and it should expand, thus confirming that it's working OK. So I tried that, and nothing. So then I tried immersing it in scalding hot water, and still nothing. But just this morning, I tried my own experiment- I used my soldering torch on it. After about 10 seconds, expansion was confirmed... twice. I'm wondering if maybe it just needed heat like that to break loose after so many years of sitting.

But I'm also curious- is there something significant about 70 degrees? Is that the point at which the 'stat should begin opening the flaps? Or should I just take the fact that the 'stat expanded under torch heat as a sign that it's in operational condition? Thanks.

Was that 70 degrees "C" or "F", there is a difference (IMG:style_emoticons/default/laugh.gif)

If I remember correctly, when I got mine off the "bay", I tested mine by putting it in a pan of water and putting it on the stove. I heated it up and it opened when the water got hot! How hot? Dunno, but hot enough to burn my hand. It wasn't boiling yet, but it was close. Seems like different T-stats open at different temps and I think they are rated at "C" - centigrade.

Warrenoliver

[jim_hoyland]

As I remember, if the bellows appears collapsed at room temp, it works; if it appears expanded at room temp, it leaks.


These have been seen at swap meets pretty regularly.

[dbgriffith75]

Okay, so here's what I've found:

First off, the only reason I put the torch to it is because I thought after so many years of sitting, there was a possibility that the internals of the 'stat were slightly froze up- not bad, but bad enough that it prevented expansion, which is why it wouldn't work submerged in water. So I used the torch in hopes that it would help break them loose and obviously since I got expansion, it did.

I tried submersing it in water again and yes, there were bubbles, BUT... after letting it sit for a few minutes I pulled it out and shook it, as you suggested 2-OH, and I didn't hear any water swishing around inside.

I realize there's a difference between 70C and 70F, but I haven't checked the book yet. What I have done, however, is use my cigarette lighter to apply heat to it; and again it has expanded. Now granted I don't know the exact heat coming off a cig lighter, but I'm pretty sure that it burns at a waaaay lower temp than the heat an engine can put off.

I suppose the only thing I can do is just get the motor running and see if the 'stat works once the engine heats up.

Thanks for the advice.

[MrKona]

See my thread from yesterday. Link

What is the length of your thermostat at room temperature? It should be around 35mm. If it measures around 46mm, it's broken. It's leaking, and has lost the negative internal pressure from the factory.

On the thread, you can see an internal shot of the thermostat... there's not really anything in there that can "freeze up".

[dbgriffith75]

On the thread, you can see an internal shot of the thermostat... there's not really anything in there that can "freeze up".

Yes I'm aware of that now- used the test on the link page and there's definitetly leakage around the old solder joints. So I've got it torn apart right now- just giving the parts time to cool off before I advance any further.

One thing I've found out tho- using torch heat to remove the old solder isn't necessarily the best way to go. I can't post a pic 'cause I don't have any way to do it, but when I was heating the old solder with my torch, the top ring of the bellows began melting through in one spot (where the cap and bellows join). Luckily I saved it before it got too bad and I'm sure I can still seal it up good; so what I ended up doing is using an old gun type soldering iron as opposed to a torch to remove it. Just a tip for anyone else that might attempt this.

[MrKona]

On the thread, you can see an internal shot of the thermostat... there's not really anything in there that can "freeze up".

Yes I'm aware of that now- used the test on the link page and there's definitetly leakage around the old solder joints. So I've got it torn apart right now- just giving the parts time to cool off before I advance any further.

One thing I've found out tho- using torch heat to remove the old solder isn't necessarily the best way to go. I can't post a pic 'cause I don't have any way to do it, but when I was heating the old solder with my torch, the top ring of the bellows began melting through in one spot (where the cap and bellows join). Luckily I saved it before it got too bad and I'm sure I can still seal it up good; so what I ended up doing is using an old gun type soldering iron as opposed to a torch to remove it. Just a tip for anyone else that might attempt this.

Excellent. Good luck with the repair. Let us know if another thermostat has been saved!

Also - agree with you on the torch. It was a little overkill. I was wishing I had a small butane torch.

[dbgriffith75]

Well it's back together now, but as to whether or not it's sealed up and operational, I don't yet know. I'm having trouble finding even 91% alcohol as you used Kona. The best I've come up with is 70% and I'm sure that's just not pure enough to work... or is it?

Perhaps there's something else I can substitute with?

Also, I want to point out a couple of things I did since I didn't have everthing available to me:

I don't have a dremel tool, so instead I used emery cloth to prep the solder surfaces between the cap and bellows. The article says its similar to plumbing repair, and that being the case, emery cloth is what most plumbers would use to prep copper pipe.

After removing the crud and solder from the top of the cap, around the threaded piece I had a somewhat nasty... uhm, tear, I guess, (can't think of how else to describe it) at the seam where the plate the threaded piece is mounted to meets the cap. Since the tear was inset, I initially filled it with solder, but as everybody knows, applying heat directly to solder has a tendency to make it ball or shrink, so instead I heated the cap from underneath, which allowed the solder to liquidize and fill in the tear better. Then I proceeded with resoldering the rest of the seam. I put it on a little thicker than I would have liked, so I sanded and smoothed it out with emery cloth.

To do the work on the cap without damaging it, I used my sheet metal clamps and clamped it on the corner, then mounted the sheet metal clamps in my vise. It worked like a charm to keep the cap solid without damage.

Just thought I'd share those tips in case some of you find yourself in the same situation.

[jim_hoyland]

Took a while to find the link, but this is a good source. I bought one from them before the dollar took a tumble.....

http://www.germansupply.com/home/customer/...ring=thermostat

[MrKona]

"Well it's back together now, but as to whether or not it's sealed up and operational, I don't yet know. I'm having trouble finding even 91% alcohol as you used Kona. The best I've come up with is 70% and I'm sure that's just not pure enough to work... or is it?"

I just did a web search and found that the boiling point of 70% alcohol is 176 degrees F, so just a few degrees lower than 91% alcohol.

So did you put the alcohol in and seal up the center hole in the threaded portion yet? If it's successfully sealed and holding negative pressure, it should remain in the compressed position... if it expanded back to it's original size at room temp, there's still a leak somewhere... Let us know.

[dbgriffith75]

*Taps playing*

We, the United Brotherhood of the 914, salute you, thermostat, for your years of faithful and unrelenting service. It is unfortunate that you had to die in such a manner, but we will never forget the sacrifices you've made for us. Per your wishes, we will now have a drink in your honor.

(IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beer3.gif)

Yeah so my stat is screwed. I went ahead with the 70% alcohol, sealed it up, and did the test. After a few minutes it heated up and expanded, and I'm like "YAY! It's alive!" and then I heard it... the absolute slightest of leaks, barely noticable over the boiling water. I pulled the stat from the water and sprayed 409 on it, and there, about in the center of the bellows, were the bubbles. After letting it cool, I stretched it out and could see a very tiny crack right at a bend, and I knew it was over. (IMG:style_emoticons/default/sad.gif)

The good news is that I did seal up the old solder joints well. (IMG:style_emoticons/default/biggrin.gif) Not that it matters now. *sigh* Oh well- at least I tried. Thanks for the link Jim- I'm gonna need it now.

[dbgriffith75]

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...that's me dancing for joy right now, because I no longer have to search for another thermostat. (IMG:style_emoticons/default/biggrin.gif)

It's weird how you can sometimes forget a simple thing like "I've got an entire spare engine" when you're focusing on the fact that you're screwed. Because that's what happened to me just a few minutes ago- I remembered that I have a spare engine- and wouldn't you know it- it just happened to have a thermostat too... a good one, if you can believe it.

It was nice and compact when I pulled it off. It measured right at spec cold- and after the water test, it measured right at spec hot. I'm sooooo happy right now.

Hooray! (IMG:style_emoticons/default/cheer.gif)