: Coolant Smell after Shut Down?

07-13-07, 08:37 AM
Recently aquired N* w/60K miles. (98 Deville)

Cars electric cooling fans kick on at about 203-206 degrees, and runs at about 194-196 when fans are on. (What temp should they come on at and what temp should it run at?)

After I get the car back in the garage and shut it off, there is a faint smell of coolant from the front of the car near the radiator.

There are no leaks that I can see, it looses no coolant (by checking tank), and runs normal.

Is this normal on these cars?

Coolant system was dealer serviced about 30K miles ago near as I can tell. I was going to drain and put new Dexcool w/GM tablets in it anyway, but would like to know if this is normal for this car first.

07-13-07, 09:23 AM
12 o'clock on the gauge is 200 + or - a few degrees. That's where it should run. The fans go to low at around 210 or with A/C on, and high at (don't quote me) 226. If you can't see any coolant leaks when it's hot, try looking with a strong flashlight, cold, at night. Sounds weird, but sometimes the flashlight beam will reflect from a wet spot or drop of coolant. Look under the radiator area from beneath the car, also. If you can smell it with no apparent loss, you're fortunate in having a good nose !!! The coolant change is a good idea......there are different schools of thought on the system sealer use, but the GM tablets are good for insurance and peace of mind.

07-13-07, 10:27 AM
I don't think the fans come on till 224 degrees. My '97 ran at 206 (summer) and 213 (winter). If you smell coolant, there is a very small leak somewhere. Check the bottom edge of the water pump cover. Mine had some seepage there and it was so small that I never got around to replacing the gasket. It's still on my workbench. Might also be a small crack in the side tank that evaporates before it drips.Whatever it is, is obviously very minor. Just keep an eye on it.

07-13-07, 12:57 PM
12 o'clock on the gauge is 200 + or - a few degrees. That's where it should run. The fans go to low at around 210 or with A/C on, and high at (don't quote me) 226.

No, I have a digital dash and keep the display on coolant temp, so it read out in numbers.

Car warms up, goes up to around 203 or so, and then I see the numbers come down to 194 pretty rapidly, telling me the fans came on. I have not just idled the car to see, but thats what it appears to do.

As far as the smell. Anyone else have any thoughts?

07-13-07, 04:53 PM
:rolleyes: Never quote from memory ^^^ earlier post. Sorry.... From the mid-year Seville 2002 FSM.........The thermostat begins to open at 188 and should be fully open by 206. The fans switch to LOW at coolant 223, or A/C on, or transmission at 302 degrees. HIGH at coolant 234, or transmission >304 degrees. Coolant circulates through the throttlebody to warm it when cold start, "cool" it when normal temp reached, therefore throttlebody NEVER goes below 200 degrees under normal conditions. (CAI $$$, anyone...?) As for cooling system sealer..."place 3 sealant tablets GM #3634621 in the lower radiator hose prior to refilling the system"....(after flush). I think the readout is telling you that the thermostat opened and the temp dropped to "low normal". Have you opened the hood and watched the described fan sequence during the 206-194 temp drop? Looks like, if that's the case, the fans are indeed coming on 20 degrees too early. Go to Radio Shack and get a small IR thermometer. It makes observing spot temps easy. (with A/C off, my STS takes FOREVER to reach low fan cut-in, even in pretty heavy traffic. I daresay most "automatic" ventilation system cars spend all 12 months of the year with the A/C in permissive "run" and the fans on low because you have to consciously turn the system off.)(At the risk of insanity, patch 2 green LED's into the fan hot circuits. When 1 then 2 fans come on, the LED's tell you.)

07-13-07, 09:13 PM
Must have been the thermostat opening then.

The engine also never had the chance to get to 223 for the fans to kick on because the A/C was on.

I will have to try it without the A/C and see what happens.

Thanks for the info