Brm crankshaft sensor issues

Joined
Sep 4, 2021
Location
Maryland
TDI
Jetta brm
Was getting a intermittently stall. Was always able to restart the car. Found it was common for the crank sensor to go out. Last week while driving it died at highway speed. Cars a 5spd. Noticed oil pressure warning was also on the dash. Restarted the car and kept going. Later it happened again and noticed no rpm reading. Got the car home with no more issues. Swapped out the sensor and now its worse. Sometimes i can get it to start. Will run for a few minutes and die. Also have gotten it to restart with no rpm showing on the dash but once again oil pressure alarm. Checked the wiring harness and repaired rubbed spots and repaired as needed. Still seem to be having this issue.
 

Rx7145

Veteran Member
Joined
May 21, 2017
Location
Ohio
TDI
2006 Jetta BRM
Any codes for the sensor? Will probably need a scanner with live data to see if it cuts out.

You may need to hook up a mechanical gauge to see true oil pressure. Probably is two separate problems.

I had a similar stalling problem. Ended up being the fuel screen in the tank was plugged.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis (where it's safe)
TDI
There are just too many to list....
New engine harness. Common issue on the BRMs. Order by VIN, grab it if available, they go in and out of stock. You'll also want a new coolant flange (the one on the head) as it is much easier to swap the harness with that off, and you don't want to reuse it. Good time to replace the tandem pump gasket, too (super easy then).
 
Joined
Sep 4, 2021
Location
Maryland
TDI
Jetta brm
I already repaired the worn wiring by the starter. I know everything wiring in this car has been junk. Yesterday i was fooling with it. What it will do is idle and die. Then i have to turn the key off and back on. Sometimes i have to leave it off for a few seconds for it to see the sensor again.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis (where it's safe)
TDI
There are just too many to list....
Trust me, you *think* you repaired the wiring. It is much worse than what you saw. The engine harness is a source of many types of issues with the engine management, often things that seem "unexplainable". I don't even waste time chasing ghosts any more. I replace the harness. Fixed, done, move on to the next. The only issue is, recently the engine harnesses have has some spotty availability, and/or take some time to obtain (red order by VIN).

I would do that before I'd pull the gearbox out and replace the CKP sensor flange (that is a much, much rarer occurrence).
 
Joined
Sep 4, 2021
Location
Maryland
TDI
Jetta brm
Trust me, you *think* you repaired the wiring. It is much worse than what you saw. The engine harness is a source of many types of issues with the engine management, often things that seem "unexplainable". I don't even waste time chasing ghosts any more. I replace the harness. Fixed, done, move on to the next. The only issue is, recently the engine harnesses have has some spotty availability, and/or take some time to obtain (red order by VIN).

I would do that before I'd pull the gearbox out and replace the CKP sensor flange (that is a much, much rarer occurrence).
Would that explain why i also get a oil pressure alarm when the ecm resorts to using cam sensor? Or is it just a alarm that means nothing?
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis (where it's safe)
TDI
There are just too many to list....
That wire is also in the engine harness, but the oil pressure alert strategy is also RPM-related. VAG had a low/high RPM oil pressure warning system with dual sensors many years back (leave it to the Germans to overcomplicate something so simple), and then later on they found a sneaky way to do the same thing (more or less) with only one sensor.

The BRM's harness has so many common chafe points that so many things could happen it is possible they are related.

When I put the new ones in, I also get some of the cloth-type electrical tape (the part number is N-105-920-02) and add more to the section coming from the plastic holder on the car, across where the starter is, and up to the first anchor point. Then I put some more on where it is near the corner of the cylinder head near where the glow plug bridge comes in, and where the branch for the front CTS, oil pressure, CKP, etc. all come down near the oil filter housing. I also put some more on the leg that goes to the intake flap, as that often gets worn, too.
 
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