Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Hey guys i have a problem with an 05 vw polo classic 1.6 BAH.
The vehicle came in last week with a no start condition.
I have scanned for dtcs and found a crank position sensor intermittent dtc. Strange thing is that I somehow have rpm but 0volt on the signal wire, no spark and no fuel. (I dont have a scope so I got no choice but to use a dvom) So I have checked wiring integrity - 100%,. So I replaced the sensor, and problem fixed. Exactly 1 week later the car has the same issue again no start - crank position sensor intermittent dtc I dont know if its a coincidence or if something is causing the sensor to fail. I have rpm again, but no fuel or spark.
I cannot check the pick-up because I need to remove the gearbox to do so as the pick-up is through the rear main seal (the ckp sensor bolts onto the rear main seal housing).
Has anybody experienced these problems? Any input will be appreciated before I remove the gearbox to inspect the seal
But, I worked on BAH engines twice and Im quite sure that they dont have a separate rpm sensor.
It does have the exact same crank sensor though (febi/2nd pic)
And, another test confirmed that - unplugged crank sensor and the rpm signal dissappeared.
This vehicle only misbehaves after being kept on idle for more than about 15min (when it heats up abit) and it will eventually cut off on its own and will not restart unless left for a few hours. The owner did also notice the tachometer (rev counter) jump around strangely just before the second sensor could get faulty.
Hey ash you get a lot of vw out there? Normally we would scope this sensor to see what happens when it gets hot. but since you don't have access to one yet verify the harness again (wiggle test) to be sure we didn't miss something the first time with the dvom assuming that's all good replace the sensor and maybe see if a better brand is available
Yeah man, alot of vw's in RSA. One of the most common cars here..
I did the wiggle test, showed no difference.. I will do the test again. Problem is the car is 100km/62mi away from me and I dont really want to do alot of travelling lol..
These engines (BAH) have a real strange design crank trigger wheel. Its basically a steel/tin type of ring that is semi mounted on the rear main oil seal housing for fitment - once fitted on, the steel ring is "pressed" onto the crankshaft flange and therefore turns with the crankshaft. The position of the steel ring is very important (has some sort of "timing" which alot of people dont get right) and is therefore sold together with the rear main seal assembly as one unit.
I am trying to figure out what could possibly be wrong,
* Heat generated by the engine shouldnt effect the sensor,
* Heat could possibly cause the trigger ring to expand and change its position but that would lead to a complete no start condition - this car starts when left for a few hours. So thats also kind of impossible.
* Is it possible that clutch particles are somehow messing up the trigger wheel? This car does have a bad clutch, starting to slip..
Hey good to hear. Does that 1 have an adjustable air gap that could have been to close to the trigger wheel? I doubt it could burn out the coil pack I would guess that's unrelated but good to hear you got it fixed
No its not adjustable, its at a fixed position - but there is an air gap limit around 0.4mm or so (cant really remember right now).. the pickup ring somehow gets worn out
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