DIY for VANOS solenoid replacement, N52

papak · 08-12-2014, 12:11 AM

I recently replaced the valve cover gasket on my ’08 E86. When I was finished, I ended up with a lumpy idle and a little hesitation on acceleration. This turned out to be coincidental to the VCG change. When I checked the codes, it showed an intake cam timing message (as well as a bunch of others). After rechecking all of my work twice, I had a local shop (South Bay Autohaus, Hawthorne, CA) run a more detailed diagnostic. This confirmed the problem with the intake cam and indicated that the intake VANOS solenoid needed to be replaced. On the recommendation of the shop owner, I replaced both intake and exhaust solenoids. Here is how it is done:

1. These solenoids are adjacent to each other at the front of the cylinder head. In order to gain access, first remove the valve cover trim plate (four hex screws, 5mm). You will also need to remove the valence that covers the top of the radiator. This consists of 8 plastic pop rivets secured by plastic Phillips screws. Carefully unscrew the screws most of the way and the rivets will pull out easily. Don’t break or lose them as they are about $4.00 each from the dealer. There are also two Torx screws, one on each side (T30) as well as two nylon plugs that stabilize the radiator (T50).

2. With a mirror and flashlight, the solenoids are easy to find now. I would advise at this point to blast the area around the solenoids with an air gun to remove any dust and other debris. After you remove the solenoids, you will have two 1” diameter holes into the cylinder head. Best not to take chances.You will need a 10mm long socket to loosen the bolts that secure them. You really don’t want to drop these bolts as you will then have to remove the pan below the engine to recover them. The electrical connectors are removed by depressing the silver clip and wiggling them off the solenoid. Note that the cable to the lower connector turns 180 degrees. The upper one is straight. Once the 10mm bolts have been removed, rotate the solenoids about a quarter turn and the will pull right out. There is an o-ring that will remain in each bore. These need to be removed and the bores carefully cleaned to remove any remaining dirt and dirty oil residue.

3. The solenoids that I removed had a different part number from the replacements. They have been updated over the years (old 1136 7 516293, new 1136 7 585425). I got mine from “BMW partssource.com” for $112.10 each. I found them priced as high as $162.00 elsewhere. The new ones work perfectly. They come with new o-rings. Once the are inserted into the head, they need a slight push to seat them. Rotate as needed to align the bolt holes and reverse the whole removal process.

4. When I restarted the engine, everything was smooth again. In fact, there definitely seems to be a little smoother acceleration now. I cleared the SES message with the Bavarian Technic software. An aside here; The Bavarian Technic software does a good job of displaying all of the fault codes but the GT-1 diagnostic setup in the shop actually describes the components that need to be replaced. It is much more directive and a godsend to shop owners as it saves a huge amount of time. $187.00 for Bavarian Technic vs $100,000 for the GT-1. You get what you pay for. I also changed the oil filter as a precaution (I had changed the oil about 100 miles earlier). I have been told that it is dirt and contamination that causes these solenoids to fail. Mine both shows a fail amount of varnish buildup on the inner mechanisms. This didn’t even budge with brake cleaner. I may sit them upright in the ultrasonic cleaner to see if I can clean them up for spares.

All in all, it took 30-40 minutes.

elerner61 · 08-12-2014, 08:48 AM

Thanks for this. You didn't take any pictures that you can add, did you?

papak · 08-12-2014, 01:33 PM

I did but the format is too large to upload. I'm still trying to figure out how to reduce the pixels to make it work.

inTgr8r · 08-12-2014, 01:41 PM

Thanks for the n52 write up

There are several online utilities that will resize for you.
Online storage utilities like photobucket will also resize as you upload.

papak · 08-12-2014, 02:23 PM

Hope the photo helps a bit.

Aries326 · 10-04-2014, 11:09 PM

How many miles was your car at when you had to replace the solenoids? Thanks for the write up!

3002 tii · 10-05-2014, 01:20 PM

FWIW I had the same rough idle a while back and found cleaning the solenoids did the trick, or at least bought me enough time *knock on wood*. IIRC, the only thing I replaced were new o-rings as those are intended to be one time use only.

I am surprised though that you replaced the VCHG. That was only an issue for early n52's (i.e. 06 models), 07+ changed over from the aluminum bolts and didn't have the leaking issue. The only potential leak I addressed was the oil filter housing gasket, and I did that as routine maintenance while doing the water pump and T-stat.

papak · 10-05-2014, 10:25 PM

I have about 44,000 mi on the car. It runs perfectly now.

08-12-2014, 12:11 AM	#1
papak Private 6 Rep 76 Posts Drives: 2008 Z4 3.0si Coupe Join Date: Sep 2012 Location: LA iTrader: (0)	DIY for VANOS solenoid replacement, N52 I recently replaced the valve cover gasket on my ’08 E86. When I was finished, I ended up with a lumpy idle and a little hesitation on acceleration. This turned out to be coincidental to the VCG change. When I checked the codes, it showed an intake cam timing message (as well as a bunch of others). After rechecking all of my work twice, I had a local shop (South Bay Autohaus, Hawthorne, CA) run a more detailed diagnostic. This confirmed the problem with the intake cam and indicated that the intake VANOS solenoid needed to be replaced. On the recommendation of the shop owner, I replaced both intake and exhaust solenoids. Here is how it is done: 1. These solenoids are adjacent to each other at the front of the cylinder head. In order to gain access, first remove the valve cover trim plate (four hex screws, 5mm). You will also need to remove the valence that covers the top of the radiator. This consists of 8 plastic pop rivets secured by plastic Phillips screws. Carefully unscrew the screws most of the way and the rivets will pull out easily. Don’t break or lose them as they are about $4.00 each from the dealer. There are also two Torx screws, one on each side (T30) as well as two nylon plugs that stabilize the radiator (T50). 2. With a mirror and flashlight, the solenoids are easy to find now. I would advise at this point to blast the area around the solenoids with an air gun to remove any dust and other debris. After you remove the solenoids, you will have two 1” diameter holes into the cylinder head. Best not to take chances.You will need a 10mm long socket to loosen the bolts that secure them. You really don’t want to drop these bolts as you will then have to remove the pan below the engine to recover them. The electrical connectors are removed by depressing the silver clip and wiggling them off the solenoid. Note that the cable to the lower connector turns 180 degrees. The upper one is straight. Once the 10mm bolts have been removed, rotate the solenoids about a quarter turn and the will pull right out. There is an o-ring that will remain in each bore. These need to be removed and the bores carefully cleaned to remove any remaining dirt and dirty oil residue. 3. The solenoids that I removed had a different part number from the replacements. They have been updated over the years (old 1136 7 516293, new 1136 7 585425). I got mine from “BMW partssource.com” for $112.10 each. I found them priced as high as $162.00 elsewhere. The new ones work perfectly. They come with new o-rings. Once the are inserted into the head, they need a slight push to seat them. Rotate as needed to align the bolt holes and reverse the whole removal process. 4. When I restarted the engine, everything was smooth again. In fact, there definitely seems to be a little smoother acceleration now. I cleared the SES message with the Bavarian Technic software. An aside here; The Bavarian Technic software does a good job of displaying all of the fault codes but the GT-1 diagnostic setup in the shop actually describes the components that need to be replaced. It is much more directive and a godsend to shop owners as it saves a huge amount of time. $187.00 for Bavarian Technic vs $100,000 for the GT-1. You get what you pay for. I also changed the oil filter as a precaution (I had changed the oil about 100 miles earlier). I have been told that it is dirt and contamination that causes these solenoids to fail. Mine both shows a fail amount of varnish buildup on the inner mechanisms. This didn’t even budge with brake cleaner. I may sit them upright in the ultrasonic cleaner to see if I can clean them up for spares. All in all, it took 30-40 minutes. Attached Images Last edited by papak; 08-12-2014 at 02:22 PM..
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08-12-2014, 08:48 AM	#2
elerner61 Major 157 Rep 1,107 Posts Drives: '07 Z4M Roadster Join Date: May 2011 Location: Mount Kisco, NY iTrader: (0)	Thanks for this. You didn't take any pictures that you can add, did you?
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08-12-2014, 01:33 PM	#3
papak Private 6 Rep 76 Posts Drives: 2008 Z4 3.0si Coupe Join Date: Sep 2012 Location: LA iTrader: (0)	I did but the format is too large to upload. I'm still trying to figure out how to reduce the pixels to make it work.
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08-12-2014, 01:41 PM	#4
inTgr8r Lieutenant General 2426 Rep 11,667 Posts Drives: M2 Comp Join Date: Mar 2006 Location: Toronto iTrader: (10)	Thanks for the n52 write up There are several online utilities that will resize for you. Online storage utilities like photobucket will also resize as you upload. __________________ '21 M2C Hockenheim Silver '18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold)
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08-12-2014, 02:23 PM	#5
papak Private 6 Rep 76 Posts Drives: 2008 Z4 3.0si Coupe Join Date: Sep 2012 Location: LA iTrader: (0)	Hope the photo helps a bit.
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10-04-2014, 11:09 PM	#6
Aries326 Lieutenant Colonel 195 Rep 1,530 Posts Drives: 2008 Z4 3.0si, 2013 E92 M3 ZCP Join Date: Aug 2011 Location: NC iTrader: (2) Garage List 2013 E92 M3 [0.00] 2008 BMW Z4 3.0si [9.00]	How many miles was your car at when you had to replace the solenoids? Thanks for the write up! __________________
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10-05-2014, 01:20 PM	#7
3002 tii Lieutenant General 2280 Rep 12,565 Posts Drives: Z4 M, X5, GX460 Join Date: Apr 2008 Location: CT iTrader: (99) Garage List F15 X5 xDrive35i [8.75] E86 Z4 M [10.00] F10 550i (Retired) [9.17] F25 X3 xDrive35i (R ... [9.43] E82 135is (Retired) [9.50] E85 Z4 M (Retired) [9.41] E90 328i xDrive (Re ... [9.25] E86 Z4 3.0si (Retired) [9.20]	FWIW I had the same rough idle a while back and found cleaning the solenoids did the trick, or at least bought me enough time knock on wood. IIRC, the only thing I replaced were new o-rings as those are intended to be one time use only. I am surprised though that you replaced the VCHG. That was only an issue for early n52's (i.e. 06 models), 07+ changed over from the aluminum bolts and didn't have the leaking issue. The only potential leak I addressed was the oil filter housing gasket, and I did that as routine maintenance while doing the water pump and T-stat. __________________ Follow for latest mods
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10-05-2014, 10:25 PM	#8
papak Private 6 Rep 76 Posts Drives: 2008 Z4 3.0si Coupe Join Date: Sep 2012 Location: LA iTrader: (0)	I have about 44,000 mi on the car. It runs perfectly now.
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