E46 VANOS Causing Crank/No-Start?

[crispychicken49]

Hey everyone! I was hoping for a better introduction for my first post here but unfortunately sometimes things go differently!

I've got a 136k mile M3 that has never had the VANOS touched to my knowledge based on the service records for the car (~10 years). On Wednesday after driving multiple times during the day I go to leave my girlfriends house and find that the car has a crank no-start condition. Okay lets pull the codes and see what we see. Generic code reader shows P0010 code for the VANOS Solenoid. Busting out INPA I get the following codes:

72: "Inlet Late Valve"
94: "Inlet VANOS adaptation"

I gave a call to Beisan this morning explaining the symptoms and codes. Their opinion was that the solenoid shouldn't be the issue but the seals being dead and no providing pressure could be. Cranking the car it will sometimes sputter like it is trying to turnover, but generally doesn't. I don't hear a cacophony of noise as if something broke or is banging the valves or anything. Ideally I would like to get the car driveable so I can move it to my house and finish a VANOS job in the garage, but after calling Beisan I am dubious that the VANOS is the issue? No other codes (besides persistent EVAP codes) are present. Some background is that early last year when I bought the car I had a crank/no-start happen. Troubleshooting pointed to the fuel pump so I replaced that and the relay which fixed the issue. The car currently has just over 3/4 tank as well (fresh the morning of the issue) so I don't believe it would be the secondary pump.

Any thoughts or experience with this issue? This weekend I'll inspect fuses but I wanted to get an idea first to see if VANOS issues could cause a crank/no-start first before I end up doing the VANOS in a parking lot.

[George Hill]

"besides persistent EVAP codes" ... Has the CEL been on previously? Could it be the FP died again and the Vanos faults have been there awhile you just didn't know because the CEL was on for the Evap fault(s)?

[crispychicken49]

"besides persistent EVAP codes" ... Has the CEL been on previously? Could it be the FP died again and the Vanos faults have been there awhile you just didn't know because the CEL was on for the Evap fault(s)?

It’s definitely possible. The CEL was on for around ~150 miles so the solenoid could be a red herring. I’ll be out to check fuses/relays and fuel pressure today to narrow down some issues.

[sapote]

72: "Inlet Late Valve"
94: "Inlet VANOS adaptation".

Generally a bad vanos should not cause crank no start. If fuel pressure is good or smell raw fuel, then I will check cylinders compression.

[crispychicken49]

Alright update time. Went to check fuel pressure, couldn't easily access the filter assembly where the car was. For some reason I unplugged the MAF and then for some reason it fired right up? Drove it home and let it sit for a day, then went to check fuel pressure. Cranked a couple times and measured ~70psi before it fell to 40 and then sat at ~20psi. Inconclusive if it was holding enough pressure post crank due to how leaky the autozone tester was. Sat the car back down and it fired right up, no issues.

I am definitely lost but I think a compression check wouldn't hurt. Timeline is as follows:
Wednesday night -> Multiple cranks no start, solenoid code. Thursday Night -> Multiple cranks, no start, multiple VANOS codes. Saturday Day -> Unplugged MAF and starts first try.

Either way VANOS needs to be done and was planned for this Spring anyway. FPR and it's block is stuck to the filter anyway, so in case the FPR is unable to keep up with fuel pressure I can replace and rule that out as well.

[sapote]

1) Cranked a couple times and measured ~70psi before it fell to 40 and then sat at ~20psi. Inconclusive if it was holding enough pressure post crank due to how leaky the autozone tester was. Sat the car back down and it fired right up, no issues.


2) I am definitely lost but I think a compression check wouldn't hurt.
3) Saturday Day -> Unplugged MAF and starts first try.

4) Either way VANOS needs to be done

1) 70 psi during cranking is good. Nobody care the P dropping with key off as it's not important. When I start my car, turn key to ON and wait for couple sec for pump to prime, then crank it.
2) need to know the baseline of the engine.
3) after engine running, did you have the same vanos codes or they gone?
4) If the pump disk is original then I would just drill 2 new smaller holes to minimize the plays, and add Loctite to those 12 bolts holding the cam sleeve. Don't waste moneys on other stuff.

[crispychicken49]

A little update in case anyone comes across this in the future:

VANOS as stated was not the issue. Fuel Pressure Regulator was also replaced (Fuel filter had seized onto the old one) however that also did not change the problem. The problem got bad enough that the car would not start most of the time.

The issue was the fuel pump. Some other grumblings on the forums about the Hella fuel pump assembly lead me to pull it and disassemble. Like the others mine also had the check valve floating in the suction pipe. As such the car would build pressure during priming, but lose pressure at some point between then and cranking. Why continuous fuel pump operation would not then repressurize the line and lead to a hesitation on start rather than a full no-start condition I don't know. Replacing the fuel pump with an "OE" unit fixed the issue and it hasn't been back since after roughly a month of driving.

If you bought the Hella FP assembly it seems it is quite likely you will also experience this issue close to a year after install. Just something to be aware of.

[sapote]

As such the car would build pressure during priming, but lose pressure at some point between then and cranking..

Why waiting long between pump priming and cranking? If you saw 70psi after key turned on for 1.5sec for example, then quickly to to crank and engine should fire up. No? With the engine running, a floating check valve should not cause any problems I think.

[E46 M3]

A little update in case anyone comes across this in the future:

VANOS as stated was not the issue. Fuel Pressure Regulator was also replaced (Fuel filter had seized onto the old one) however that also did not change the problem. The problem got bad enough that the car would not start most of the time.

The issue was the fuel pump. Some other grumblings on the forums about the Hella fuel pump assembly lead me to pull it and disassemble. Like the others mine also had the check valve floating in the suction pipe. As such the car would build pressure during priming, but lose pressure at some point between then and cranking. Why continuous fuel pump operation would not then repressurize the line and lead to a hesitation on start rather than a full no-start condition I don't know. Replacing the fuel pump with an "OE" unit fixed the issue and it hasn't been back since after roughly a month of driving.

If you bought the Hella FP assembly it seems it is quite likely you will also experience this issue close to a year after install. Just something to be aware of.

Yes my 3yo Hella check valve has also gone, I paid $99 for it at the time so it is what it is. This time round it will be much more expensive with how expensive shit has gotten.