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Discussion Starter #1
Alright guys, I need your help. My 07' 530i died on me about 2 weeks ago. Towed car to indy to diagnose issue. Indy simply diagnose some issues and threw parts at it. Overall, didn't get my car to start. BAD SITUATION...anyways. Relays are good. Fuses are good. I'm getting fuel and spark, but no combustion. I compression tested my N52 and this is what I'm getting.

Cylinder 1: 70-75
Cylinder 2: Around 90
Cylinder 3: 135 then dropped to 90
Cylinder 4: Around 85
Cylinder 5: 90
Cylinder 6: 90

The engine had no issues up til the day it cut off. I'm wondering what could cause the compression to drop so low like that? Car still wont start. Any ideas?
 

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If you didn't put the valvetronic system in max lift position the compression would be low. Unplug the eccentric shaft sensor, this forces the valves to the max lift position and puts the engine in throttle body control, and see if it will start. If it doesn't start then do a compression test with the sensor unplugged and see what you come up with. How do you know you are getting fuel and spark?
 

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Discussion Starter #3
If you didn't put the valvetronic system in max lift position the compression would be low. Unplug the eccentric shaft sensor, this forces the valves to the max lift position and puts the engine in throttle body control, and see if it will start. If it doesn't start then do a compression test with the sensor unplugged and see what you come up with. How do you know you are getting fuel and spark?
For fuel, gas is all on the plugs and sprays for the fuel rail when tested. For spark, had my buddy test with the #1 spark plug out and it has spark. So you said disconnect the VVT motor and see what it does?
 

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Discussion Starter #4
For fuel, gas is all on the plugs and sprays for the fuel rail when tested. For spark, had my buddy test with the #1 spark plug out and it has spark. So you said disconnect the VVT motor and see what it does?
My bad, the eccentric shaft sensor?
 

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Discussion Starter #5
UPDATE: So unplugging the eccentric shaft sensor did up the compression a little but it didn't start the car. Anything else it could possibly be?
 

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What did the compression come up to? The only accurate test for fuel pressure is with a gauge, wet plugs doesn't mean anything. A spark plug may fire when not in the cylinder but not fire when it is in the cylinder. To verify the coil can produce adequate spark i like to use one of these https://www.amazon.com/Thexton-THE404-Spark-Tester/dp/B0002STSBM Are there any codes stored in the DME? If you have fuel, air and spark the only thing missing to create a running engine is timing.
 

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Discussion Starter #7
What are the chances that my N52 jumped timing? I had the car timed earlier last year due to the serpentine belt being sucked in it. Car was running fine until 2 weeks ago. Was just driving then just died while driving. No codes or and hesitations of the sort.
 

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What are the chances that my N52 jumped timing? I had the car timed earlier last year due to the serpentine belt being sucked in it. Car was running fine until 2 weeks ago. Was just driving then just died while driving. No codes or and hesitations of the sort.
How long was it running after that repair? Given this problem, my first guess would be some other collateral damage from the belt-sucked-in problem or the fix afterwards.
 

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Discussion Starter #9
Car ran fine after the repair. No issues at all. And that was February of 2018 when the car was repaired from the belt.
 

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Discussion Starter #11
When checking the timing, what exactly am I looking for to be off? I read somewhere about the barcodes on top of the cams or something of that sort. I have access to an N52 timing tool in case.
 
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