360 Cluster of problems, maybe electrical

Seeking some advice on the right sequence of steps to take to diagnose and resolve some problems that popped up on my 2003 360 F1 transmission, ideally spending the minimal amount of money along the way.

Before this, I’ve never had any CELs or other issues in the 3 years I’ve owned the car. And it stays on a battery tender when not in use.

Here’s a chronology of little things that happened last week. Before this I hadn’t driven it in about a month.

1. Sat 8/26 ran rough while warming up at idle. Was oscillating between about 500 and 1500rpm. I started my drive and that behavior stopped. Drove (with stops) 200 miles to my road trip destination, including some spirited driving.

2. During that drive, there were a few times that my OEM stereo changed from playing music from my phone (via Bluetooth into an adapter that’s plugged into the CD changer port) to suddenly the FM tuner. Electrical gremlin?

3. Mon 8/28 drove 150+ miles back toward home. No issues, though will note that this is probably the hottest I’ve ever gotten the car, between the length of the trip, the sustained modestly spirited speeds (under 100, nothing crazy), and it being 90 degrees F outside.

Made a pit stop. On start up, I couldn’t reverse, so shut the car back off. I looked up threads here on FChat and used the trick of shifting into R from 1st instead of neutral. Was on my way again.

4. Less than 10 miles later, I was sitting in traffic and the low oil pressure light went on. I started pulling over to get to a safe place where I could shut the car off, but the light went off before then. I pulled the car over anyway and shut it off for a bit (to cool I guess? that was a scary light to see). Turned it back on. No light. Drove home. I continued to watch the gauge and it seemed to vary between 35 and 70 PSI depending mostly on whether I was idling or driving at freeway speeds.

5. That same evening, after several hours of being turned off, sitting in the driveway, I started her up to back into the garage. Didn’t run the engine for more than a minute while doing so. Closed the garage door. About 15min later my garage’s carbon monoxide sensor triggered. I opened the garage door to air things out. Ridiculously, my monitoring service said they had to send out the fire department. They walked around my garage w their CO sensor for a bit, made sure we were okay, and gave the all clear.

6. Tue 8/29 I started her up to head to the office. Nothing unusual. About 2-3mi down the road I got a CEL so decided to turn around. Finally had some time yesterday to pull the code and got a P2177 “System too lean off idle Bank 1”.

Any insights or advice would be much appreciated.

A single underlying cause vs a coincidence of a few different things failing?

Probably safe to drive to the shop, or get it towed? Should I erase the code and see if it comes back or the car otherwise complains?

I have some time/energy/ability to inspect simple things myself, but not anything that’s too involved.

If I take it to my shop, other than laying out the above, what should I ask them to inspect or service?

Thanks in advance!

 

Fwiw the battery is only 18mo old. But no matter, will check those voltages and get back here.

Maybe points to the alternator, if that’s what’s failing to keep the battery where it needs to be after a whopping 2.5 days away from a tender.

 

Took a bunch of measurements. All with a multimeter connected directly to the battery.

On tender 9/2 8pm 13.37
Off tender 9/2 8:01pm 13.26
9/3 9am 12.64
9/4 9am 12.49
Ignition turned to on 9/4 9am 12.2
Cranking 11.x (high 11s)
Running 14.4
Driving 14.3
After 5min 14.2
After 10min 13.8
After turning ignition off 13.3

Car ran normally the entire time. AC turned on. CEL still on. No other indicators of anything unusual.

 

To Rifledriver’s comment re its running rough and my driving it anyway, I guess I’ll add the detail that it sounded fine…what I called its running rough was that it was failing to keep the revs at 1000ish equilibrium. It would drop down to 500 like it’s stalling, sputter for a moment, bounce up to 1500, then repeat. My thought process was that by starting to drive I would get it out of that oscillation. Notwithstanding, I get it. Next time I’ll turn the car off, restart it, and see if that resolves it.

I did not yet erase the CEL. Is the preferred way to do that with an OBD tool, or by turning off the battery in the frunk?

After that, seems like I should just go ahead and drive it normally, until some symptom reappears?

 

Started her up, connected OBD2, cleared the P2177, went for a drive. Filled the gas tank 10min in, and drove for another 20min, putting her through the paces. No issues, no lights, no unusual behaviors.

Shrug, guess I’ll just treat it as a fluke for now, until any symptoms reoccur, or I do another 3-day road trip.

 

What do you mean by mixed results?