My experience with replacing throttle actuators

[Jims M3]

I read a lot of DIY's and information on replacing the throttle actuators, from rebuilding them with new gears, to electrical rebuilds of boards.

I had a code for Bank 2 throttle actuator and decided I would start by rebuilding the bad unit with new gears, since I was in there I ordered gears for both banks and figured I would replace both.

First off you shouldn't be afraid to do the DIY on this job, it is very easy. The Plenum comes off in minutes and then your looking at the wiring loom. Follow the DIY, unplug the connections and the engine loom lifts up for easy access to the actuators.

I discovered that one of my actuators had a date code of 2015 on it and was fairly new. When I opened it up I could see that the gears and unit were pretty much flawless but decided to put in the upgraded gears. I bought them off of Ebay they are the units with brass on the flywheel reduction gear, and it comes with an installed shaft.

http://www.ebay.com/itm/BMW-M3-E90-E...BYMr2a&vxp=mtr


I also replaced the gear in the Bank 2 which was the original. I re-installed and test drove it, 3 miles in I get the same code back again. I ended up then buying a new actuator from FCP Euro they sell them for $766 and they come with a lifetime parts warranty. So I left the unit stock and installed it, figuring if it fails I'll get a new one from FCP.

My advice would be the following

1. Don't be afraid to do this job, it is very easy, easier than changing spark plugs, which I would recommend doing when you do this job. If you replace your spark plugs, do yourself a huge favor and buy this tool. It makes the job 10x easier.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

2. Rebuilding a unit with a code for a failed actuator and the board looks dark is probably not worth rebuilding. My experience was the spring in the new unit was stronger than the original and the board's had a noticeable difference in color.

3. Replace the unit and if your going to buy a new unit consider FCP, you can't beat the lifetime warranty on parts.

https://www.fcpeuro.com/products/bmw...m3-13627838085

All told I could swap this in about 1.4 hours start to finish, and that is with drinking a beer in between. It really is very easy to do.

I took pictures of the work before I started so I knew were all the plugs went, but seriously it would be pretty hard to mess this up. They only fit going to their proper locations.

No more codes the car is driving perfect now. Don't pay a dealer huge money to do this job. Worst case two actuators are $1,500 and that is the last time you do them if you buy the parts from FCP. I don't think I would even install the upgraded gears. The upgraded gears are definitely heavier than the stock gears, and I question if they are truly engineered for this unit. It puts more stress on the spring, electronics and motors.

[bkdore]

I found the hardest part was figuring out how all the different electrical connectors release. Mechanically swapping the actuator was really easy.

[Jims M3]

I took it apart two times testing the replacement gears, so I got really efficient. these cars are not bad to work on compared to some.

[jpra923]

Thanks for sharing! I think I will definitely go your route when it's time to replace!

[Lexustbs]

the price is now $760 for the throttle actuator. Read about the Vanos solenoids on the S85 (which I came from), they went from $185 a piece to over $1200 a piece, there are 4, and they go bad......


I might just buy two actuators when the price drops again just for safety, and possibly a investment!