Lurch/Jolt and CEL When Accelerating/Heater Not Blowing Consistently

Hello all… Newbie here, so I appreciate you checking out my query. I’ve never been a car person, so bear with my inarticulate attempts to explain what’s going on – I read the “monologue” and will do my best to abide!

I recently purchased a 1995 530i, with an automatic transmission, approx 280k miles. The previous owners installed a rebuilt transmission and new rear brake light wiring within the past year.

About three days after I got it home last month I was just getting on the freeway and accelerating at about 50mph when the car began lurching or jolting, for lack of a better word, and the check engine light came on each time it lurch/jerked and then it would resume accelerating. The car never came to a standstill, but if I’d been in a manual I’d liken what was happening to it stalling, feeling-wise.

This has happened one more time, this week, again as I was on the freeway accelerating and around 50mph.

I checked out the links on how to do a “stomp test” and did it this afternoon. I’m having a hard time figuring out the code. What I was getting looked more like Morse code than the code in the example video (mine was 1-short, 1-long, 1-short, 1-long and then repeating ad nauseum). Maybe I did the test inaccurately? Could the 1 long be more like an uninterrupted 2 pulse? If so, that would make the code 1212, which is the Oxygen Sensor 2. But again, I am just making this up. Here’s a video, let me know what you think?

I also did the dashboard cluster test but am not sure how to interpret the reading or if it’s even relevant to this issue. But I’ll post that too.

Finally, I don’t know whether to consider them related, but the heater has been going off and on for the past two weeks. Sometimes I turn the dial all the way up and there is just no air blowing. Others it blows faintly and cold. Other times it cranks up just fine. There is often a loud thumping in the dashboard area when the heater comes on. Like I said, I’m not sure if it’s related but figured it was worth a mention.

Before you worry that your advice will be in vain since I’m such a novice, fear not. I will be able to get my brother to do the heavy lifting but I need to show him the courtesy of doing the legwork first and trying to take care of what I can. If you can suggest somewhere I can look to learn more about this, or ideas on what the issue may be I'd really appreciate it.

Thanks so much for taking a look at this!_a_

Hmm, I'm inept. The videos didn't link in my last post.

Dashboard Cluster Test


Stomp Test

Check system voltage, battery connections, ground straps. The stomp test seems to be malfunctioning. This car will behave very erratically if it's not getting 12-plus volts. That's the first thing I'd check.

I also think you have a bad electrical connection, and it could be directly related to the blower fan not working properly as well as the stalling. Good place to start!