What The Hell Is This Mystery Contraption Found In A Used BMW?

Illustration for article titled What The Hell Is This Mystery Contraption Found In A Used BMW?

Recently, an adventurous fellow named Serge spotted a little red 1991 BMW 318is sitting forlornly in the parking lot of a repair shop. Serge asked if it was for sale, and was told yes, it wouldn’t start and could be his for the cost of scrap! Fantastic! Then, he got it home, opened the trunk, and found a mystery.

The mystery is pretty simple: what the hell is the big-ass contraption of boxes, wires, tubes, and pipes that’s sitting in the trunk? What did this thing do, and who did it do it for? Is it here to help humanity, or hasten our downfall?

Let’s see if we can figure this thing out.

The thing looks home-made, but purposeful; it doesn’t appear to be some sort of automaker emissions-testing equipment or anything like that.

Illustration for article titled What The Hell Is This Mystery Contraption Found In A Used BMW?

The thing appears to be two black metal boxes joined by a smaller aluminum-looking box-section piece. There’s a large rubber hose on the ‘top’ of the box, connected via a 90° tube and terminating in a large screw-on cap.

The ‘lower’ black box has a fan on one side, and an intake grille for the fan on the other. The unit also has a large electrical connector composed of two sets of 15 wires, and some wires in between. The warning sticker on the base reads “WARNING CAUSTIC PRESSURIZED LIQUID/LIGHT SENSITIVE COMPARTMENT/HAZARDOUS CURRENT” which gives a nice variety of hazards to be worried about.

The aluminum middle section also has a bit of house plumbing-type copper pipes and fittings which seem to feed into some sort of fitting and then into the ‘upper’ box.


There’s a bunch of now unconnected wires and hoses about, in the trunk and and under the hood. Serge told me that there was a hose that went into a port on the intake in front of the throttle body:

Illustration for article titled What The Hell Is This Mystery Contraption Found In A Used BMW?

“... it first goes [through] an aluminum tube that looks like ac accumulator and from there into the intake.”

Serge also provided this handy annotated picture of where the hose was connected.


Whatever this thing is, it appears to be doing something to the intake, possibly adding something. There’s been speculation it was a device to let the car run on fuel vapor, though it seems like there’s an awful lot of electronics on this thing for that.

Perhaps it’s some sort of water-methanol injection system? But there don’t appear to be any fluid bottles or tanks, so that’s maybe not the answer.


Commenters on Serge’s Facebook post about this have suggested that maybe its one of those hydrogen-extracting electrolysis units to let a car ‘run’ on water, even if it’s not really running on water at all.

I’m really not sure, but this seems like a fun Friday afternoon challenge for all of you, the automotively-smartest collection of oil-stained geeks on the global compu-net.


Serge just hopes it’s not a bomb or a shitty tracking device of some sort, and I’m pretty sure it’s neither of those things.

But what the hell is it?

Senior Editor, Jalopnik • Running: 1973 VW Beetle, 2006 Scion xB, 1990 Nissan Pao, 1991 Yugo GV Plus, 2020 Changli EV • Not-so-running: 1977 Dodge Tioga RV (also, buy my book!: https://rb.gy/udnqhh)

Share This Story

Get our newsletter



Whatever it is I’m sure the fuel companies hate it.