T-Stat Orientation Arrow -Important or Not? - PeachParts Mercedes-Benz Forum

warmblood58 · #1 10-11-2010, 02:34 PM

In my haste to complete my citric flush/ t-stat replacement, I failed to orient the t-stat with the arrow pointing up. My question is does this matter? Not a big deal to drain/reorient t-stat, just a pain -any thoughts on this?

tangofox007 · #2 10-11-2010, 03:00 PM

Quote:

Originally Posted by warmblood58

Not a big deal to drain/reorient t-stat, just a pain -any thoughts on this?

There are plenty of vehicles where it is a pain to replace a thermostat. Your's isn't one of them.

Is there any chance that you can be happy unless the arrow is pointing north?

warmblood58 · #3 10-11-2010, 03:04 PM

Quote:

Originally Posted by tangofox007

There are plenty of vehicles where it is a pain to replace a thermostat. Your's isn't one of them.

Is there any chance that you can be happy unless the arrow is pointing north?

Happiness is not the issue, already happy, just wondering if the orientation really matters or not -does anyone know? I imagine that the arrow may assist with the burping/air bleeding process somewhat though upon inspecting, can't tell the difference!

winmutt · #4 10-11-2010, 03:06 PM

Of course it does. There is an arrow on a one way street sign, do you follow that one as well?

warmblood58 · #5 10-11-2010, 03:47 PM

Quote:

Originally Posted by winmutt

Of course it does. There is an arrow on a one way street sign, do you follow that one as well?

big day for sarcasm here on the forum -was hoping for more objective definitive feedback versus quips - can anyone tell me why the arrow is important based upon the construction of the t-stat itself -now that would be helpful. Studying the one sitting next to me on the desk, I do not see an obvious feature that would explain why the arrow orientation to the top -

winmutt · #6 10-11-2010, 04:46 PM

You asked if it mattered, now why there was an arrow. I don't know either

warmblood58 · #7 10-11-2010, 06:03 PM

I did a quick pull/re orient - I was off 110 degrees or so so now arrow is up. Gauge reading lower (for now) and I have cycled a few times on ramps with heater on. Funny thing, several years ago, before a trip, I paid my indie to look over car and do a flush/refill -I swear gauge temp read higher after that which makes me wonder if he bothered orienting the t-stat. I have confirmed proper temp with thermal gun and need to pull instrument panel to recheck ground connection and replace reserve light bulb-should be interesting to see how temps respond in the next few days of driving -

cmbdiesel · #8 10-11-2010, 08:54 PM

I'm going to go out on a limb here, and suggest that they arrow (indicating flow direction) is to keep the t-stat from being installed backwards.
Without knowing what vehicle you are installing this on, my guess is that the t-stat inserts in a horizontal position, not vertical? If so, I would further imagine that as long as you see the arrow, then you are OK. Rotating the t-stat will make no difference, flipping it end for end, probably not so good.

tangofox007 · #9 10-11-2010, 09:54 PM

Quote:

Originally Posted by cmbdiesel

I'm going to go out on a limb here, and suggest that they arrow (indicating flow direction) is to keep the t-stat from being installed backwards.

Crack!!! That wasn't a very sturdy limb.

micalk · #10 10-12-2010, 09:16 AM

Isn't there a tiny hole at the top (when oriented correctly) to allow air to escape the engine?

tangofox007 · #11 10-12-2010, 09:23 AM

Quote:

Originally Posted by micalk

Isn't there a tiny hole at the top (when oriented correctly) to allow air to escape the engine?

If there is, it's irrelevant on the 617.95 engine, which had a bypass air passage built into the thermostat housing. But the same thermostat is used on other engines, so it might matter in other applications.

vstech · #12 10-12-2010, 09:47 AM

how about pics?

Stevo · #13 10-12-2010, 11:15 AM

Quote:

Originally Posted by cmbdiesel

I'm going to go out on a limb here, and suggest that they arrow (indicating flow direction) is to keep the t-stat from being installed backwards.
Without knowing what vehicle you are installing this on, my guess is that the t-stat inserts in a horizontal position, not vertical? If so, I would further imagine that as long as you see the arrow, then you are OK. Rotating the t-stat will make no difference, flipping it end for end, probably not so good.

Not so, the arrow indicates "up" or "fwd"