Refilling coolant system how-to?

[jlglr4]

Thanks, that’s helpful. Looks like you have the SCV6. I seem to recall that mine runs even a little hotter - maybe 215-220, but that was in pretty hot outdoor temps. I need to measure again.

I had not thought to measure my temps before I did the coolant system repairs/bleed, but measured them afterwards and was alarmed by temps getting up to 220 because the only temps I’d seen reported earlier were for the V8 (usually not above 200F). Then I discovered through some research that there are different t-stats on the V8 vs V6. Seems the V6 engine runs a thermostat that opens at around 204-207 and is not fully open until 228, whereas the V8 models run a thermostat that opened around 180F or 190F and was fully open around 203F. So, I’m thinking above 228 is a worrisome range as there is no additional cooling capacity at that point.

 

[greiswig]

That's interesting, @jlglr4 . I wonder why LR would make that change? For fuel economy?

 

[jlglr4]

That’s the only reason I can think of. It would be interesting to see how the car would react to using the lower temp thermostat (and see if there is really any difference in the mpg). It might try to defend itself: “Just what do you think you’re doing, Dave?”

 

[16FujiDisco]

I'm not sure they are interchangeable. When I did mine I actually ordered the scv8 part in error; everything is the same except for an electrical connector that the SCV6 version has. Made me assume the the scv8 was a mechanical tstat and the SCV6 was electric. I'm sure it would throw some kind of code without having that plug connected.

 

[greiswig]

I'm not sure they are interchangeable. When I did mine I actually ordered the scv8 part in error; everything is the same except for an electrical connector that the SCV6 version has. Made me assume the the scv8 was a mechanical tstat and the SCV6 was electric. I'm sure it would throw some kind of code without having that plug connected.

I assumed that connector was to a sensor, not an actuator.

And (wild speculation follows) one wonders if the plastic parts were designed to be used at the lower temperatures and pressures that the V8 thermostat makes for, and if that might have something to do with premature failures. Some of the pictures I've seen almost make it look like the O-rings are reacting chemically with the plastic and degrading it, which might not happen at lower temperatures.

Speculation, though.

 

[jlglr4]

I believe the connector is for a heating element that allows the computer a little control over how quickly the t-stat opens. I seem to recall that’s how electric t-stats work for the most part. Didn’t know that was missing in the V8.

Its also occurred to me that the whole coolant pipe issue might be exacerbated by the higher temps in the SCV6. For sure, it’s always been a problem, even in the V8, but we’re seeing degradation at pretty low mileage in the V6 models.

 

[cashgtr313]

There is a manual bleed method in the manual, which is what I did. Here’s the rundown:

(1) Get the coolant reservoir free and raise it up about 1.5”. You can’t raise it up much, but it doesn’t take much. Just need the rim higher than the highest bleed point. I think I lifted it a bit, and just put something underneath it to hold it up. Manual says to remove the headlight to get the reservoir free, but I don’t think that’s necessary.

(2) Open all the bleed points. There is one on the front crossover (plug), one near the firewall, one on the tube leaving the top of the radiator, and one on the reservoir itself.

(3) Fill the reservoir all the way up and watch for coolant at the first bleed point (front crossover). Once that starts bleeding, cap it.

(4) Keep filling until you see coolant at the second bleed point near the firewall. Close that bleed point.

(5) Close the bleeder on the reservoir. You now have just the radiator tube bleed open.

(6) Start and run the engine. Continue to top with coolant and watch for coolant at the radiator tube bleed point. Once it bleeds, close it.

(7) Turn the motor off and wait at least a minute. Top up the coolant if needed.

(8) Turn the heater controls to maximum and restart the car.

(9) Hold the RPMs at 2000 until the coolant level in the expansion tank drops.

(10) Increase to 3500 RPM until hot air is emitted from front and rear face vents. Keep an eye on the coolant level and keep topping up a couple inches above the cold fill range. Also watch your temp gauge - make sure something isn’t going awry.

(11) Let it idle until the coolant level stabilizes - hot air should still be coming out of the vents.

(12) That’s it. Shut it off and reinstall the reservoir. Top it up just above the cold fill if its not already there and check it frequently for the first few drives.

Thank You