'06 325i N52 Crank No Start

tej98 · 07-24-2022, 05:32 PM

Hey everyone, a bit stumped on this one. Helping out a neighbor with his 2006 325i. To preface this, the car was running perfectly fine before any of this happened.

Neighbor changed out all 6 coil packs and spark plugs for preventive maintenance (approaching 110k miles). All the old coil packs came out leaving rubber from the boots on the spark plugs so each spark plug chamber was vacuumed out prior to removing the plugs to avoid anything falling inside the combustion chamber.

Once this was done, new plugs and coils were installed. It seems early N52 cars had a slightly different coil pack connector with a centering notch located to the side of the connector and the new coil packs had the notch on the center of the connector. So each notch was cleanly filed away on the new coil packs so the connectors could fully seat.

After this, the car exhibited the crank but no start symptoms. We have verified the fuel pump primes via INPA, and tested for fuel at the fuel rail. We removed a spark plug and coil pack and attempted to start the car and saw a spark produced so the ignition signal is being sent from the DME.

There are no stored codes in the DME when scanning with INPA except for a radiator blind error that was present well before this work.

What else can we troubleshoot here? We have put the old spark plugs in with the new coil packs and have the same result. Battery has also been charged so it is fresh.

Any other thoughts? Thanks in advance!

PumpkinBimmer · 07-24-2022, 07:29 PM

Quote:

Originally Posted by tej98

Hey everyone, a bit stumped on this one. Helping out a neighbor with his 2006 325i. To preface this, the car was running perfectly fine before any of this happened.

Neighbor changed out all 6 coil packs and spark plugs for preventive maintenance (approaching 110k miles). All the old coil packs came out leaving rubber from the boots on the spark plugs so each spark plug chamber was vacuumed out prior to removing the plugs to avoid anything falling inside the combustion chamber.

Once this was done, new plugs and coils were installed. It seems early N52 cars had a slightly different coil pack connector with a centering notch located to the side of the connector and the new coil packs had the notch on the center of the connector. So each notch was cleanly filed away on the new coil packs so the connectors could fully seat.

After this, the car exhibited the crank but no start symptoms. We have verified the fuel pump primes via INPA, and tested for fuel at the fuel rail. We removed a spark plug and coil pack and attempted to start the car and saw a spark produced so the ignition signal is being sent from the DME.

There are no stored codes in the DME when scanning with INPA except for a radiator blind error that was present well before this work.

What else can we troubleshoot here? We have put the old spark plugs in with the new coil packs and have the same result. Battery has also been charged so it is fresh.

Any other thoughts? Thanks in advance!

I just did VC gasket, spark plugs, Valvetronic seal and coils and running into the same issue... I said screw it and ordered new coils that have the offset tab. BECK/ARNLEY 1788480 are the ones I am going to try when they arrive... I'll let ya know if that fixes the issue

tej98 · 07-25-2022, 07:42 PM

Quote:

Originally Posted by PumpkinBimmer

I just did VC gasket, spark plugs, Valvetronic seal and coils and running into the same issue... I said screw it and ordered new coils that have the offset tab. BECK/ARNLEY 1788480 are the ones I am going to try when they arrive... I'll let ya know if that fixes the issue

Thanks, that would be much appreciated! Were you getting a spark off the spark plugs when connected to the coil packs?

ro881e · 07-26-2022, 09:11 AM

Sure I saw a similar post to this recently... If I am not mistaken. The coil pack plugs were not fully seated even though the clips/tabs were 'home'. Worth shoving them in with a bit more oomph?

hassmaschine · 07-26-2022, 09:51 PM

You can get new coil connectors and a release tool to swap the early to late plugs. I haven't done this yet, but it wasn't super expensive, and was actually less than the cost difference from new coil packs vs the original style coil packs. I got them from FCP. I think there is probably more to it than than just whatever tab you ground off.

tej98 · 07-28-2022, 06:16 PM

We actually found the exact coil packs (matching part number) on FCP and swapped those in today with fresh plugs and same result. Unfortunately nothing else has changed so this is a really odd result. The new coil packs fit perfectly this time around with no connector issues and no trimming required.

tej98 · 07-30-2022, 09:20 PM

Turned out to be cylinder wash down. Too much cranking with improperly connected coil packs caused fuel to wash down the combustion chamber. Half a cap full (small amount) of oil down each chamber and the car fired right up no issues since.

Proper coil packs with the offset connectors from FCP as well as fresh NGK plugs have it sorted out nicely. If you have something similar I'd recommend this diagnosis path.

07-24-2022, 05:32 PM	#1
tej98 Private First Class 68 Rep 156 Posts Drives: '09 335i Join Date: Feb 2021 Location: GA iTrader: (0)	'06 325i N52 Crank No Start Hey everyone, a bit stumped on this one. Helping out a neighbor with his 2006 325i. To preface this, the car was running perfectly fine before any of this happened. Neighbor changed out all 6 coil packs and spark plugs for preventive maintenance (approaching 110k miles). All the old coil packs came out leaving rubber from the boots on the spark plugs so each spark plug chamber was vacuumed out prior to removing the plugs to avoid anything falling inside the combustion chamber. Once this was done, new plugs and coils were installed. It seems early N52 cars had a slightly different coil pack connector with a centering notch located to the side of the connector and the new coil packs had the notch on the center of the connector. So each notch was cleanly filed away on the new coil packs so the connectors could fully seat. After this, the car exhibited the crank but no start symptoms. We have verified the fuel pump primes via INPA, and tested for fuel at the fuel rail. We removed a spark plug and coil pack and attempted to start the car and saw a spark produced so the ignition signal is being sent from the DME. There are no stored codes in the DME when scanning with INPA except for a radiator blind error that was present well before this work. What else can we troubleshoot here? We have put the old spark plugs in with the new coil packs and have the same result. Battery has also been charged so it is fresh. Any other thoughts? Thanks in advance!
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07-26-2022, 09:11 AM	#4
ro881e Private 37 Rep 98 Posts Drives: E90 330i N52 2007 M-Sport Join Date: Jul 2020 Location: Cambridge, UK iTrader: (0)	Sure I saw a similar post to this recently... If I am not mistaken. The coil pack plugs were not fully seated even though the clips/tabs were 'home'. Worth shoving them in with a bit more oomph?
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07-26-2022, 09:51 PM	#5
hassmaschine Major General 3966 Rep 7,215 Posts Drives: "NBO" 330i Join Date: Jun 2014 Location: earth iTrader: (0)	You can get new coil connectors and a release tool to swap the early to late plugs. I haven't done this yet, but it wasn't super expensive, and was actually less than the cost difference from new coil packs vs the original style coil packs. I got them from FCP. I think there is probably more to it than than just whatever tab you ground off.
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07-28-2022, 06:16 PM	#6
tej98 Private First Class 68 Rep 156 Posts Drives: '09 335i Join Date: Feb 2021 Location: GA iTrader: (0)	We actually found the exact coil packs (matching part number) on FCP and swapped those in today with fresh plugs and same result. Unfortunately nothing else has changed so this is a really odd result. The new coil packs fit perfectly this time around with no connector issues and no trimming required.
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07-30-2022, 09:20 PM	#7
tej98 Private First Class 68 Rep 156 Posts Drives: '09 335i Join Date: Feb 2021 Location: GA iTrader: (0)	Turned out to be cylinder wash down. Too much cranking with improperly connected coil packs caused fuel to wash down the combustion chamber. Half a cap full (small amount) of oil down each chamber and the car fired right up no issues since. Proper coil packs with the offset connectors from FCP as well as fresh NGK plugs have it sorted out nicely. If you have something similar I'd recommend this diagnosis path.
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