VicCrownVic's 1998 Mercury Grand Marquis LS

[VicCrownVic]

Hit enough drive/run cycles with proper O2 sensor readings and the CEL finally went out. I didn't clear the codes after replacing the O2 sensors because I wanted the PCM to register enough proper data to shut the CEL off on its own, which it finally did. Now I'm code free again on this car.

Turns out it really is a bad cat. Since the light did go out eventually with the new sensor, the original sensor may not have been great. However, the light is back on with the same code. Voltage output in ForScan of upstream and downstream sensors show the downstream sensor follows the upstream sensor quite nicely. It's not supposed to be like that; that means the cat pretty much is doing nothing between the 2 sensors. Fairly certain the root cause is the bouncing landscape brick I hit on M59 a couple of years ago that damaged one of the cats on that side (driver). (Vehicles on either side of me but none behind so at least I braked and I didn't hit it at 70-75mph).

And another incident of "I'm an idiot" today. After the cooling fan fiasco last summer I flushed the cooling system. (The '02ish fan is doing great by the way.) When I refilled it I assumed the remaining water in the block from flushing it would be negligible. Well, turns out that assumption wasn't so true (assuming I've diagnosed my situation properly). It was so cold this morning but my temp gauge pegged high and the digidash started beeping at me. Thinking it was a fluke or bad sensor I pulled over on a dirt road and let it idle a minute. The gauge stayed pegged. So I shut it off a minute (also, it was still completely dark outside). Checked under hood and nothing was off/wrong yet. Started the car again and the gauge was normal temperature. Decided to turn around and work from home anyway just in case. I was only 8.5 miles (13.679km) from home. I made it 0.5mi (0.8km) and it started to boil over. Pulled off onto a other dirt road and shut it off a bit longer (the sun was getting close to rising by now). Looked under the hood again to make sure I didn't have blown hoses or anything major, and I found that I didn't have anything more than typical boil over. When I started the car again the gauge was normal again and stayed that way the 8 miles back home.

So, based on the steady -12°F (-24.44°C) on my outside air temp right before this all happened, I've figured that my water to antifreeze ratio was closer to 60/40 which has a freezing point of -10°F (-23.33° C) so maybe between 55/45 and 60/40. I figure this less than ideal ratio allowed the coolant in the radiator to freeze at -12°F. The boil over perhaps thawed the radiator enough to reestablish flow.

After I was done working for the day, I filled with concentrated antifreeze to make the ratio better, then I let it get up to temp to make sure there were no leaks and everything looked good. I then threw the garbage cans in the trunk to make the 600ft (about 183m) round trip down and back up my driveway to put the trash to the road. Then I found an excuse to run to town (2 mile (3.22km) round trip) just to get some drive time in.

As long as it really was freezing coolant in the radiator, I think I should be good to go now. The much warmer temps forcasetd for tomorrow morning (16°F/ -8.889°C) so that should help too.

[Tiggie]

Hope all is well with your cooling system. Definitely some cold starts lately.

[DerekTheGreat]

Oooh, you got lucky there. Cracked block would be no bueno.

Although my "I'm a F'n idiot moment" rates right up there. I somehow killed our snow thrower by running straight gas in it instead of 50:50 as called for. The shit smelled oily and was bluer, not to mention in the can labeled "Gas/Oil mix" so I don't know what happened there. A "new" one has already been acquired, but that's a bonehead thing for this shade tree mechanic...

Cold starts indeed. Our Tahoe does not like to start when the temps are below 10F. The F-150 fires right up, my K1500 protests like an old man being told to get off the couch and go to bed after a few beers, but does comply and run on all eight when it lights off.

[VicCrownVic]

The Ice Car didn't like cold starts the first winter I had it on the road. Since I figured it was a fuel issue I ran ISO Heet in that car and it gradually came around and would start no problem even when we had that polar vortex (vortices?) roll through here in about 2014 or 2015.

'98 made it to work with no problems this morning. Thinking about it now, I think there actually was a warning sign of a problem on Tuesday. The outside temp reading hit -12F briefly on Tuesday on the way to work, and I think the coolant in the radiator was on the cusp of freezing which hindered flow which caused the heat to not be an inferno like usual. It was back to the usual inferno today, so it could have been because it was so dang cold or it may have been a warning sign that just didn't click in my head.

[DerekTheGreat]

It happens. As with that snow blower, I received the sign, just went in the wrong direction. "Simple things first." I should've checked the gas mix first.