Coolant not flowing, could this (see pic) be why?

[TomInAlaska]

This is what I found just now while in the process of installing a new thermostat. The issue I'm trying to rectify is incipient overheating due to a suspected lack of coolant flowing out of the engine.

I've tried to drive the van outside the neighborhood a couple of times now and had the temp gauge never really stop climbing and even showing a blinking LED until I stopped to let it cool off and then scurried back to the safety of the driveway. Even idling in the driveway the temps would continue to climb to the high side of the gauge. After idling for about 10 mins this morning, my IR gun showed temps at the thermostat housing or ~200F and 220+F at the heads. The coolant hoses in the engine bay however were about 150F (I don't remember the exact numbers, but they were significantly lower than the engine itself or thermostat housing). And the radiator and coolant hoses at its base were ambient (~60F here in Anchorage today).

I went to the FLAPS and got a thermostat thinking mine was stuck closed but wanted to get y'all's opinion on whether A: what I found with the old one (has VW/audi stamps so I suspect it might be original) would cause my symptoms and B: should I fix the old OEM one and put it back in or install the new aftermarket thermostat.
_________________
'73 Super Beetle (resto-mod/rally look, 1776)

'84 GL adventure van project (1.9L, 4speed) https://www.thesamba.com/vw/forum/viewtopic.php?t=755844&highlight=

[TomInAlaska]

After looking at the new aftermarket unit, its actually made by the same company, Behr, in Germany and looks like its actually an improved design. So, unless I see anything to the contrary in the next few minutes, the new one is going in!
_________________
'73 Super Beetle (resto-mod/rally look, 1776)

'84 GL adventure van project (1.9L, 4speed) https://www.thesamba.com/vw/forum/viewtopic.php?t=755844&highlight=

[DanHoug]

you're pull out has a discombobulated mount so, yeah, it ain't going to open properly. put the new one in and Bob's your Uncle.
_________________
-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[TomInAlaska]

Somethings still not right. I got the new thermostat installed and replaced about the same amount of coolant that drained out (a little over a gallon) but after idling for about 10 minutes, the gauge is still creeping up and giving me a flashing LED. IR gun says the thermostat housing and the hex of the temp sensors are about 200F but the hoses on the firewall are no more than 135F and the pipes under the van are ambient (about 65F now). Spare is stock size, but I checked under there anyway and everything looks good. Could I have an air bubble trapped somewhere?
_________________
'73 Super Beetle (resto-mod/rally look, 1776)

'84 GL adventure van project (1.9L, 4speed) https://www.thesamba.com/vw/forum/viewtopic.php?t=755844&highlight=

[TomInAlaska]

I may have spoke too soon. I tried letting it idle again just to see if any air bubbles may have worked themselves out and now it seems to be cycling hot coolant through the radiator like its supposed to! I didn't wait for the fan to come on, but the tanks were ~185F per the IR gun. And the thermostat housing seemed to have stabilized at about 190F from a high of 205F.

So, I'll give driving out of the neighborhood another shot and see what happens, but I've got a good feeling.
_________________
'73 Super Beetle (resto-mod/rally look, 1776)

'84 GL adventure van project (1.9L, 4speed) https://www.thesamba.com/vw/forum/viewtopic.php?t=755844&highlight=

[Yellow Rabbit]

It’s very easy to have trapped air in the system. There are a mile of pipes and hoses and dozens of places to tap air. The radiator and motor are both higher than the horizontal main pipes. Read up on bleeding the system properly and do that. I have always found the 1.9 to be harder to bleed than the 2.1 vans.

[TomInAlaska]

I got a gowesty pump in one of my recent orders and have been using that to try to get any air out of the radiator bleeder. When I tried today I only got coolant the three or four times I checked.

Something I did that seemed to get a few more bubbles out of the hoses and into the expansion tank was repeatedly squeezing all the hoses I could in the engine bay with my hands. Its something I started doing to my '92 F150 (with the 4.9L, one of the best engines ever made, fight me about it!) that seemed to burp a little bit of extra air out of the hoses and get a little more coolant in its place. Did doing that help in this case? Who's to say.
_________________
'73 Super Beetle (resto-mod/rally look, 1776)

'84 GL adventure van project (1.9L, 4speed) https://www.thesamba.com/vw/forum/viewtopic.php?t=755844&highlight=

[zoti]

A simple test would be to let the van warm up and then touch the hoses going to the radiator. If they are hot, your thermostat is working.

Does your radiator fan turn on?

[TomInAlaska]

Oh during my last test the thermostat was definitely working, the radiator tanks got up to 185F according to my IR gun. I didn’t wait to see if the fan would kick on but I did test it a few days ago by jumping the plug at the radiator switch and both speeds seem to work. I’ll just have to trust that the switch itself is still good. But then again, it never really gets much over 70F here so not a big deal if it isn’t. 🙃
_________________
'73 Super Beetle (resto-mod/rally look, 1776)

'84 GL adventure van project (1.9L, 4speed) https://www.thesamba.com/vw/forum/viewtopic.php?t=755844&highlight=

[borninabus]

sounds like you're working through it but you should understand that the thermostat lets coolant that has passed through the rad back into the engine, converse to most other cars.
_________________
88 Van WBX, A/T - 13 JSW TDI 6M/T - 2012 Touareg TDI Sport

[TomInAlaska]