How do VANOS solenoids age? When to replace?

unixnerd · 09-05-2020, 10:35 AM

So last week I cleaned my N52's VANOS check valves, one was filthy. Got a lot more power between 3-4k miles.

Today my new VANOS solenoid O-rings finally arrived so I've removed and cleaned them. They didn't seem dirty but got a good dose of MAF cleaner anyway (I also cleaned the MAF). I applied 9V to the terminals and they clicked cleanly and opened about 1mm. I'd swear one moves more than the other but hard to tell.

When these die is it a case of total failure or do they degrade over time? I'm chasing a lack of low down power basically. Done a major service and replaced the usual bits but it still seems weaker than it should be under 3500.

Phil325i · 09-05-2020, 11:34 AM

Rather than replace the solenoids I would first check/clean/replace the VANOS filters. Part No. 11367507729 (you'll need two).

unixnerd · 09-05-2020, 12:46 PM

Did that last week, one clean one filthy. Good a good bit more oomph. Just had a wee drive after cleaning the solenoids and it's made a small difference. Cleaning the filters really made a big difference.

Zack_e90 · 09-09-2020, 01:10 PM

Quote:

Originally Posted by unixnerd

So last week I cleaned my N52's VANOS check valves, one was filthy. Got a lot more power between 3-4k miles.

Today my new VANOS solenoid O-rings finally arrived so I've removed and cleaned them. They didn't seem dirty but got a good dose of MAF cleaner anyway (I also cleaned the MAF). I applied 9V to the terminals and they clicked cleanly and opened about 1mm. I'd swear one moves more than the other but hard to tell.

When these die is it a case of total failure or do they degrade over time? I'm chasing a lack of low down power basically. Done a major service and replaced the usual bits but it still seems weaker than it should be under 3500.

The Vanos solenoids do age over time, however, from my experience they seem to age faster when the oil is not changed frequently. Regardless of driving habits ex (hard-driving or tracking) just changes the frequency of oil changes. What happens when you don't change your oil before it becomes more viscous is the oil becomes very thick and mixes with metal shavings/carbon deposits (normal wear and tear) and gets trapped and clogs the solenoids. Just be sure to change your oil filter and oil frequently and you should be fine!

unixnerd · 09-09-2020, 01:49 PM

Previous owners weren't very good at changing oil, it came out black. Solenoids seem OK since I cleaned them and they click very positively when I apply a battery. I just wondered if there was any point in replacing them. Is the failure mode that they just gum up and die or do they gradually open less with age?

09-05-2020, 10:35 AM	#1
unixnerd Second Lieutenant 215 Rep 211 Posts Drives: E46 325Ci, Z4, E30 318iS Join Date: Jul 2020 Location: Scotland iTrader: (0)	How do VANOS solenoids age? When to replace? So last week I cleaned my N52's VANOS check valves, one was filthy. Got a lot more power between 3-4k miles. Today my new VANOS solenoid O-rings finally arrived so I've removed and cleaned them. They didn't seem dirty but got a good dose of MAF cleaner anyway (I also cleaned the MAF). I applied 9V to the terminals and they clicked cleanly and opened about 1mm. I'd swear one moves more than the other but hard to tell. When these die is it a case of total failure or do they degrade over time? I'm chasing a lack of low down power basically. Done a major service and replaced the usual bits but it still seems weaker than it should be under 3500. __________________ www.unixnerd.co.uk - providing Nerdy BMW stuff since 1996!
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09-05-2020, 11:34 AM	#2
Phil325i Brigadier General 639 Rep 3,215 Posts Drives: E92 325i MSport Coupe Join Date: Apr 2012 Location: UK South East iTrader: (1) Garage List 2009 BMW 325i Coupe [6.00]	Rather than replace the solenoids I would first check/clean/replace the VANOS filters. Part No. 11367507729 (you'll need two). __________________ E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; 3 x chassis braces; diff brace; N53 V-brace; 034 subframe inserts; BMS clutch stop; BMS CDV; RE g/box mounts; Delrin shift bushes; Saikoumichi OCC; Cyba scoops; BMW Perf Exhaust; HEL s/steel brake hoses; M3 rear spoiler; Recaro Sportster CSs; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof/clear front
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09-05-2020, 12:46 PM	#3
unixnerd Second Lieutenant 215 Rep 211 Posts Drives: E46 325Ci, Z4, E30 318iS Join Date: Jul 2020 Location: Scotland iTrader: (0)	Did that last week, one clean one filthy. Good a good bit more oomph. Just had a wee drive after cleaning the solenoids and it's made a small difference. Cleaning the filters really made a big difference. __________________ www.unixnerd.co.uk - providing Nerdy BMW stuff since 1996!
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09-09-2020, 01:49 PM	#5
unixnerd Second Lieutenant 215 Rep 211 Posts Drives: E46 325Ci, Z4, E30 318iS Join Date: Jul 2020 Location: Scotland iTrader: (0)	Previous owners weren't very good at changing oil, it came out black. Solenoids seem OK since I cleaned them and they click very positively when I apply a battery. I just wondered if there was any point in replacing them. Is the failure mode that they just gum up and die or do they gradually open less with age? __________________ www.unixnerd.co.uk - providing Nerdy BMW stuff since 1996!
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