Does the 87 degree wahler thermostat for the 20020vs have an arrow on it for orientation?

I just finished installing mine but didn't look for an arrow... and now I'm not sure if I actually saw one.

Anyone have one handy? My old wahler thermostat doesn't have an arrow but I lost the brass cross brace and I'm not sure if the arrow was on that.

on another note: removing the thermostat was a bit ackward. I had to use a 10mm socket without any extensions and had to snake my hand down from the ABS controller behind the dipstick to get to the thermostat housing.

<ul><li><a href="http://www.sjmautotechnik.com/trouble_shooting/cooling.html#hose">http://www.sjmautotechnik.com/trouble_shooting/cooling.html#hose</a</li></ul>

The spring side of the T-stat is always on the "from" point of view. And the air bleeder (if equpped) is always up (12 O'Clock).

If you flipped the T-stat_, it might not fit under it's cover and will bleed cold coolant thru as the pressure of the flow will be on the wrong side of the spring.

HTH.
-Scott

I have the spring side going into the block. That much I do remember from the old thermostat.

My thermostat doesn't have an air bleeder. The bentley shows the thermostat installed with the cross brace goin vertical, and the old thermostat had the crossbrace going horizontal.

I think it doesn't matter, but I wanted to make sure. I'll probably remove it and check later this morning.

I haven't filled the coolant yet (or attached hoses) because I was waiting for the high temp silicone I applied to the thermostat to dry over night.

Just went back in to have a look at the thermostat. Took me 30 minutes to remove and clean off old silicone and replace.

Having small hands is a big plus here.

there is no arrow on the 87degree wahler thermostat. I installed the thermostat so the crossbrace is vertical (|) as shown in Bentley, instead of the way my mechanic installed it last time (-), though I doubt it makes any difference.

Tools I used are 1/4" ratchet with 10mm socket. Using a 3/8" 10mm socket all by itself was helpful in removing the bolt once it was loose.

removed the plug on the sensor in the radiator, and the throttle cable. Snaked my right arm down across the after-run pump in front of the dipstick while I rested my chest on the fender for support.

I used antiseize on the housing bolts and snugged up the bolts only using the 1/4" ratchet and will get my 3/8" ratchet in there for one more snugging down of the 2 bolts.

15lbs of torque is just a bit more than the valve cover bolts.


I decided to use a bit of silicone on both sides of the thermostat so it wouldn't get stuck to the block from galvanic corrosion.

I accidentally put it in the way you mechanic did (-) as that's how the 12v V6 does it and I thought it would be the same. NOT! On the highway the coolant was getting sucked into the block into an air bubble and causing a low coolant light. I changed the orientation of the thermostat to the way it's supposed to be (!) and it's fine again. Here's a pic I posted in a while back to warn people of doing it wrong.

<img src="http://pictureposter.audiworld.com/43547/t-stat.jpg">

<center><img src="http://img241.imageshack.us/img241/6454/thermostatqb2.jpg"></center><p>what ElsaWIN says about early A8 with 4.2 V8 engine (basically the same like in V8) thermostat

from SJM's site:

Install the thermostat with the cross brace vertical, orientated at 12 and 6 O'clock

I was wondering if there was an arrow on the thermostat, this info is just as good.

I'm glad I went back in to turn it the way Bentley was showing it.

OK, so final conclusion is:
for 20V - vertical;
for 32V - horizontal.
?? ?

Prior to replacing my thermostat, my temp gauge was hovering just under the large hash at 11:00 at idle and would drop if I hit Auto on the CC or started driving. Heat was somewhat tepid but I didn't think anything of it since I had the temp set to 66 degrees.

with the new thermostat, I get up to normal operating temp in about 5 minutes of driving. The temp stays at slightly above the large 11:00 hash mark and the heat comes on strong and hot even though it's set to 66degrees.

I'm currently experiencing a 3-4 mpg improvement and expect that average to drop down to 2-3 mpg improvement once I work some heavy footery into the mix.. but I did replace the coolant sensor at the same time.

so prior to thermostat replacement, I was getting around 14.5 mpg on 2 days of short conservative driving style trips in town and today I'm looking at 18.5mpg.... not terribly scientific or even consistent but a definite and clear difference.

I should pay myself back for the parts and labor in a short time if the mileage improves with the warmer weather in the spring.

interestingly, Boost is the same as before, but the car feels much more lively. I guess it's timing related but who cares.