3.0L engine swap

[Farrar]

Evaporated coolant has left behind rust dust, just as Matt David suggested:

rusty papertowel.jpg

[Ron]

Just in case, check THIS LINK out.
Plug in a 3.0 Primer...notice it shows two types of OE thermostats (with alternate temps).
The OE Inlet type is 198° and the OE Outlet type is 190°.

I'd use the OE shown for whichever type you have and not worry about the 8° difference -- Like most engines of the day, D engines need a thermostat rated at 180°F+ (for lubrication etc), but in order to get the O2 sensor up to its operating temp quicker, they raised the temp rates 12° (or so), which gets the system into closed loop quicker....

[Farrar]

The OE Inlet type is 198° and the OE Outlet type is 190°.

I noticed that when I was looking up the part on RockAuto. Unfortunately, I have no idea what an inlet thermostat is or how it differs from an outlet thermostat. They looked the same to me.

[SamHill]

THERM.DERM.SQUIRM.HERM.JPG

[Ron]

I noticed that when I was looking up the part on RockAuto. Unfortunately, I have no idea what an inlet thermostat is or how it differs from an outlet thermostat. They looked the same to me.

??? the link I gave you explains the difference in the descriptions...has to do with how/where they mount.

[Farrar]

??? the link I gave you explains the difference in the descriptions...has to do with how/where they mount.

Oops. By the time you posted the link, the replacement thermostat was already ordered and on its way. I should have put both sentences in past tense rather than just the first one. Brain fart.

Moving on: a comparison photo. Stock DMC/Volvo thermostat on the right, lower opening temperature Eagle/Dodge thermostat on the left. Stock DMC/Volvo definitely has a stronger spring.

thermostat comparison.jpg

Interestingly, they're both stamped "MotoRad," even though one of them was sold as a DuraLast at AutoZone and one was sold as a MotoRad from Amazon.
DuraLast is stamped "Germany," MotoRad has no stamp to indicate origin.
And that's enough trivia for one day.

[Farrar]

Well, I know I'm going to get chastised for not having done my homework, but I was eager to get started, so here's what happened.

1. Raised the front of the car so that I could get a bucket underneath the lower radiator hose.
2. Raised the rear of the car slightly higher than the front.
3. Opened thermostat housing, removed thermostat, and closed thermostat housing.
4. Added one 22-fl.oz. bottle of Prestone cooling system flush fluid to system.
5. Filled the system the rest of the way with (distilled) water.
6. Started engine and ran it until temperature reached 220 degrees. This took about ten minutes.
7. Stopped engine and allowed it to cool.
8. Removed radiator cap and drained fluid at lower radiator hose. It was the color of black coffee. The Prestone cooling system flush fluid made it look soapy. Fine powdery deposits settled at the bottom of the bucket into which I drained the fluid.
9. Sealed the system back up and re-filled with another 22-fl.oz. bottle of Prestone cooling system flush and more water.
10. Started the engine and ran it until the temperature reached 220 degrees. This took a lot less time. I noticed the cooling fans were not coming on, so I inserted a jumper into the Otterstat terminals to turn on the fans. (Note: the fans had been working normally during the drive from Jacksonville to Plantation. This failure is a new symptom, so I consider it a separate problem.)
11. Stopped engine and allowed it to cool.
12. Removed radiator cap and drained fluid at lower radiator hose. At first the fluid was slightly brown, but toward the end it was mostly clear, with the soapy look again.
13. Opened thermostat housing, installed 170-degree thermostat, and closed thermostat housing.
14. Filled the system with one gallon of antifreeze and slightly less than one gallon of water. This surprised me, but I planned to burp the system anyway.
15. Started the engine and watched the level of water in the funnel go down. I added water until no more water bubbles were coming up the funnel, but I had still not used the full gallon of water. The engine reached 220 degrees in less than three minutes, and running the cooling fans did not help to cool the system down.

I am guessing there's a blockage in the cooling system somewhere.

Question: If I remove the thermostat and close the housing back up, then connect a garden hose to the bleeder and open the system at the lower radiator hose, would that flush the entire system, or would I be missing a loop somewhere?

[Farrar]

Here's a photo of the radiator cap and thermostat which were replaced.

The radiator cap obviously had a leak, since there's coolant in the gauge.

I'm not sure if the thermostat is brass, or if the gunk in the coolant stained it.

old thermostat and radiator cap.jpg

[81dmc]

Just disconnect the hose on the passenger side from the aluminum piping and stick a garden hose in towards the water pump. Also disconnect the lower hose from the radiator, then proceed to flush.


Also, make sure the foamy solution is completely out before refilling the system with antifreeze.

[dn010]

If you run it with the expansion tank cap removed, do you see coolant/water flowing in from the small hose? As another cause besides a blockage, your pump could be bad and not moving any coolant.