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In what direction is the thermostat placed?


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As awd turbo said, you should only ever use a genuine subaru thermostat. They're like $15.

The pin thing is called the jiggle pin, it lets air bubbles in the system get out into the rad. IIRC on mine it's facing the back of the car, but I doubt it matters. The thermostat is round so it shouldn't make a difference.

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let me intrude and ask another noobish q...

 

I saw in the subaru EA "performance" (lol i know) post (here) about replacing w/ a lower temp Tstat - to open it sooner. I'm not really chasing HP (i know better), but like it running cooler when possible.

 

So to my point and Q - anyone know parts numbers for the 170 or 180* Tstat's?

 

The relevant info from that site:

Thermostat

The thermostat is one of the most overlooked performance enhancements. By reducing the operating temperature of the engine a number of things happen.

 

First, volumetric efficiency is increased. That is when the engine runs cooler the air/fuel mixture entering the engine is also cooler. A cooler mixture means the mixture is more dense. The higher the mixture density the more that can be packed into the cylinder. You would be surprised how much more responsive the engine becomes just by changing the thermostat from 195°F to 180°F.

 

The next step would be a 170°F thermostat. 170°F thermostats for the EA series engine are hard to find however almost any 170°F thermostat with a 54mm diameter will work. The little 'jiggler'' valve is not required but its preferable. The valve helps to purge air in the system and allows a slight flow of water around the thermostat to eliminate any temperature differentials between the area around the thermostat and the engine itself.

 

Second, with the combustion clambers running cooler a lower octane fuel can be used. Or if you're looking for better low-end torque, you can advance the ignition timing a few degrees without having to worry about detonation. (Author's note: After installing a 160°F thermostat the performance increase was negligible. However, I was able to advance the ignition liming another 2° and use 87 octane[R + M/2] gasoline with NO detonation at all!)

 

Thanks!!

 

rob

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Yes - changing the thermostat to a lower temp one is of dubious performance potential. You are talking fractions of a HP on an engine of this size.

 

The potential for damage due to the engine not reaching it's proper temperature is not worth the benefits. Especially on an engine with 100k+ on it. The components are used to running at a specific temp - if you change that then metals don't expand as much as before, tollerances change, and oil viscocities change - making the probability of damage that much higher.

 

That page has a lot of poor performance sugestions. It should be taken down or changed.

 

GD

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Yes - changing the thermostat to a lower temp one is of dubious performance potential. You are talking fractions of a HP on an engine of this size.

 

The potential for damage due to the engine not reaching it's proper temperature is not worth the benefits. Especially on an engine with 100k+ on it. The components are used to running at a specific temp - if you change that then metals don't expand as much as before, tollerances change, and oil viscocities change - making the probability of damage that much higher.

 

That page has a lot of poor performance sugestions. It should be taken down or changed.

 

GD

 

Thanks GD! I appreciate the validation (or whatever the opposite is)... I typically take everything i read online w/ a grain of salt, but it made sense to me.

 

I only have 11k on my engine, so maybe a 180 vs 195 would help? Not with HP, but just long term cooling?

 

with so few miles, i'm not really in a rush one way or the other, but mine did sit quite a bit and working out some quirks as we go.

 

Thanks!

 

rob

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why do you say that? but you can do as you want i just post this from experience of the problems i've had with new thermostats that just did not work right

 

 

I bought a new t-stat online, from Rock Auto, I think about a year to 18 months ago. It is a Beck Arnley and was advertised as a direct replacement. So not from a Sube dealer.

 

It has been fantastic. The gauge (and there is nothing wrong with the gauge) reads mid-way between Cold and the half-way mark to Hot. So at about the 1/4 mark. It is a 180 degree stat (direct replacement for my year & model).

 

Today I drove 120 miles round trip and was in stop & go traffic around 4:30 pm in Portland, OR, trying to get on the bridge over the Columbia on I-5 into WA, just like thousands of other cars. The outdoor temp today was in the mid-90s and it felt like blast furnace - that super-hot, super dry desert air. And my t-stat never rose.

 

I'm extremely happy with it & see no problem ordering online from a parts vendor where I can get a direct match.

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Some brands are better than others, some people have better luck than others. But there are TONS of stories about aftermarket t-stats causing big issues that the majority of us will just spend the extra few $ to get a subaru one.

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If it is bled properly.. (Filled up, started, warmed up so the t-stat opens, and filled the rest of the way while the coolant is flowing.) Any "Direct Replacement" t-stat will work. The reason we want Genuine Subaru T-stat is because it has a "jiggle valve" that allows a small amount of coolant to trickle through at all times and is a BIG help in preventing air bubbles in our cooling system.. that ends up in hot spots that ends up in blow head gaskets or worse. It doesn't 'trickle' enough coolant to affect the proper operating temperature range.

 

And, I'm sorry I have to comment about the "blast furnace hot dry desert heat" comment from PORTLAND. It NEVER gets "blast furnace" up there. (I spent 6 years in Columbia/Clatsop counties.) You are just used to that cold disgusting 9 months of rain so when it gets 'warm' you feel like you're cooking. Come spend a summer down in Tucson or (even worse, Phoenix) where it is 100+ daily for a few months. There is always a good week every summer that we get 110+ daily with below 10% humidity. THAT's blast furnace. (I've been in Phoenix where it was still 100+ at 11 at night!!) We pray for a nice cloudy with a breeze day where it gets down to the mid 90's.

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If it is bled properly.. (Filled up, started, warmed up so the t-stat opens, and filled the rest of the way while the coolant is flowing.) Any "Direct Replacement" t-stat will work. The reason we want Genuine Subaru T-stat is because it has a "jiggle valve" that allows a small amount of coolant to trickle through at all times and is a BIG help in preventing air bubbles in our cooling system.. that ends up in hot spots that ends up in blow head gaskets or worse. It doesn't 'trickle' enough coolant to affect the proper operating temperature range.

 

And, I'm sorry I have to comment about the "blast furnace hot dry desert heat" comment from PORTLAND. It NEVER gets "blast furnace" up there. (I spent 6 years in Columbia/Clatsop counties.) You are just used to that cold disgusting 9 months of rain so when it gets 'warm' you feel like you're cooking. Come spend a summer down in Tucson or (even worse, Phoenix) where it is 100+ daily for a few months. There is always a good week every summer that we get 110+ daily with below 10% humidity. THAT's blast furnace. (I've been in Phoenix where it was still 100+ at 11 at night!!) We pray for a nice cloudy with a breeze day where it gets down to the mid 90's.

 

My t-stat was installed at my auto repair shop.

 

If you know Portland & you know Phoenix & Tucson (and I know them well, along with Tucumcari, Gallop, and Banning and Indio and Blythe) then you know that when Portland gets temps in the 90s and next to no humidity then it feels like a blast furnace. I am very familiar with the high & low desert areas in the western half of the U.S. so I know what blast furnace temps feel like. I am not from here but from one of the driest, high desert cities in the U.S.

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Yes - changing the thermostat to a lower temp one is of dubious performance potential. You are talking fractions of a HP on an engine of this size.

 

The potential for damage due to the engine not reaching it's proper temperature is not worth the benefits. Especially on an engine with 100k+ on it. The components are used to running at a specific temp - if you change that then metals don't expand as much as before, tollerances change, and oil viscocities change - making the probability of damage that much higher.

 

That page has a lot of poor performance sugestions. It should be taken down or changed.

 

GD

 

 

reminds me of the edmunds page I saw yesterday saying it's ok to drive a little ways to the auto parts store without an air filter in so you can make sure you have the right filter...

 

:rolleyes:

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reminds me of the edmunds page I saw yesterday saying it's ok to drive a little ways to the auto parts store without an air filter in so you can make sure you have the right filter...

 

:rolleyes:

If one was going to do that, I don't understand why they wouldn't just leave their filter in, then take it out to check at the auto parts store... :confused:

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By the way, it's okay to drive a car short distances without an air filter (something you can't do with a missing fuel filter).

I'm surprised they didn't say you could duct tape the fuel line together and drive it without the filter...

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