[dr3wski]

Hi, I received the "Check Coolant Level" on my DIC. I checked the manual and it says to check by opening up the Coolant Cap on the surge tank, I guess there's a dipstick attached.

I can only get it 1/4 turn counterclockwise, it seems to release, and rattle back and forth, but it won't budge when I try to pop it off. Any ideas, before I take a flat-head screwdriver and try to pry it... ??

Any tips for adding Dexcool:"Drinkable Water" (1:1, per the manual)

Thanks all!

-dp-

 

[Submariner409]

Sounds like your reservoir has the twist lock style cap - release it the 1/4 turn, then push straight down on the cap and continue to remove it.

Sort of like this ?????

No dipstick - look at the picture and adapt it to your reservoir.

 

[00 Deville]

It does take quite a bit of downward pressure on some styles of the cap to be able to turn them. You should be fine just adding straight Dex to top off the tank... if your going to dilute the Dex 50/50 use distilled water or buy the premixed 50/50 Dexcool. Don't fill it past the full mark on the side of the tank or the car will burp the excess out the overflow.

 

[Texan4Life]

+1 you have turn it again while pressing down on it. Kinda like the cap on a pill bottle.

 

[Ranger]

Yup, that's the kind he has Sub.

When you put the cap back on be sure to press down hard as you twist it back into position. When finished, the arrow should be pointing at the overflow hose. If no, it's not on securely or properly.

 

[dr3wski]

Wow, thanks all for the quick responses and that detailed image. That's exactly what's under the hood of my caddy--and yeah, I had to put some good shoulder/tricep strength into unscrewing that thing (like I said, I bet no one has touched it in easily five years, this car has 70K on it.)

Explain to me how I'm supposed to use the cold fill legend and arrow ??? Does this black band point to an arrow near the seam? How can I see through to see where the level is actually at???? The car was dead cold, I thought I saw some fluid sloshing around the bottom half the reservoir, but when I popped the cap off and looked straight in, it seemed pretty empty in there (I'm dealing with low-light conditions because my flashlight is MIA).

I'm going to buy some 50/50 mix and top it off tomorrow. Just please let me know how to read that level indicator on the side of the reservoir, because I really don't want to test the overflow

Thanks again, all!

-dp-

 

[dr3wski]

I see the manual says fill it to 4.5" below the filler cap ring, so I'll just eyeball it. If anyone has any other pointers please let me know. I don't think I have a leak because there's nothing leaking from the vehicle--like I said, I don't think anyone has filled this thing up in years, so it probably just evaporated slowly, over time.

Thanks!

-dp-

 

[00 Deville]

Full should be about 2 1/2" below the filler neck. If you can't document a coolant change in the last 3 years you need to do one soon.

 

[Ranger]

Explain to me how I'm supposed to use the cold fill legend and arrow ??? Does this black band point to an arrow near the seam?

Yes, about 1/2 full or like 00 Deville said 2 1/2" below the base of the filler neck.

so it probably just evaporated slowly, over time.

It's a sealed system. There is no evaporation.

 

[maeng9981]

FYI, if your coolant level is getting low, there is a leak somewhere in the cooling system.

 

[dr3wski]

Ok, so I just took a short drive, enough to warm the vehicle up to the standard 1/2 level of the water temp indicator on the dash. I parked, slowly opened the coolant cap (wasn't interested in getting burned), heard a brief hiss as the pressure escaped, opened it all the way and voila, I had the 4.5" level from the cap that the manual recommends.

I checked my coolant hoses, which were warm/hot and then I realized the fans were not running. Now I'm driving around in 40-45degree (farenheit) weather, so I don't imagine this would be enough to turn the fans on.

Does the coolant sensor have anything to do with the fans being operative or not?

Tomorrow (when I have sunlight), I'll check my tank when it's totally cold and see if there's anything in there. I noticed there's an internal white stick inside the reservoir-- Is that what I use to fill up to?

I still can't see an arrow on the black band outside of the reservoir, so I might just have to eyeball it.

Is the full code mark at the top of the tank? Or is it somewhere down, to the bottom right???

Thanks again!

-dp-

 

[Submariner409]

With NO A/C or DEFROST set in the HVAC controls, fans are controlled by the ECT sensor - fans go to SLOW at 224 degrees and FAST at 236 degrees, so it's possible that fans would never run if you did a mile or so warmup and got on the highway or light traffic conditions. With any function set that runs the A/C compressor, fans run in SLOW all the time, so the temp gauge should sit within a couple needles' width of 12:00 all the time.

The thermostat begins at about 186 and is fully open at 206 - so if you look at the annotated gauge, you're normally running around with the thermostat about 90% open.

The pressure cap (16 or 18 psi, depending on model/year) prevents coolant boilover until at least 265 degrees. Unpressurized coolant boils at 218 degrees, so be very careful when opening a hot system: it's entirely possible that the hot coolant could flash to steam as the pressure is relieved. Be careful.

COLD, the coolant level should be just at or slightly above the reservoir seam.

 

[Ranger]

Ok, so I just took a short drive, enough to warm the vehicle up to the standard 1/2 level of the water temp indicator on the dash. I parked, slowly opened the coolant cap (wasn't interested in getting burned), heard a brief hiss as the pressure escaped, opened it all the way and voila, I had the 4.5" level from the cap that the manual recommends.

Fill it to 2.5" from the base of the cap or half full, NOT 4.5". If the manual says 4.5" it's probably a misprint.

 

[dr3wski]

Wow, thanks for all the detailed replies. My 2004 Deville has the Digital display (which I hate, but what can ya do), and it always sits at 4/8 bars (center). Anyways, I opened up the tank today, after the car had been dead cold for 20hours. There was coolant in the reservoir to the top of the transparent plastic--just where the transparent part of the surge tank meets the black upper part. This is about 4" below the neck of the fill cap.

I left the cap off, started the car and let it warm up a bit, which is what the manual says to do for when you're adding more coolant. The coolant level didn't seem to drop down that much.

I drove it around for about 10 miles (mainly city driving, but up and down some serious hills) and did not have the Check Coolant Level display pop up at all.

Is a 2" differential (in the surge tank) of Coolant enough to trip a sensor?

Thanks.

-dp-

 

[Ranger]

OK, curiosity got the best of me so I went out in the garage and checked and measured mine. I'll be damned if half full (as you described) is not 4 - 4 1/2". You are at the right level. Sorry for the confusion and my apologies to the FSM for doubting it.

 

[jimsbox]

Am I crazy or isn't there a molded line on the white translucent plastic on the driver side of the reservoir indicating the cold fill level?

 

[dr3wski]

So if the check coolant DIC appears again, what should I make of it? Any idea what could have tripped it in the first place?

Thank you

-dp-

 

[jimsbox]

These cars have a common problem with the coolant level sensors giving false readings. I have heard of people taking the reservoir out, filling it with a mixture of water and liquid dish soap and shaking it well, be sure to rinse all the bubbles out when you finish. The only other alternatives are to just check coolant visually periodically or replace the coolant reservoir.

 

[Submariner409]

Yep ^^^^ - entire reservoir. Amazon automotive section. probably about $60 shipped. The level sensor is not a separate item. Got one for the Seville last fall..........GM part in a Delco box.

 

[Ranger]

Am I crazy or isn't there a molded line on the white translucent plastic on the driver side of the reservoir indicating the cold fill level?

Nope, you're perfectly sane. It's exactly as you describe.

So if the check coolant DIC appears again, what should I make of it? Any idea what could have tripped it in the first place?

Stuck sensor (float). Follow jimbox's advice, "shaken, not stirred" (pun intended).