Any advices for wastegate adjustment on our 135i ?

[studio54]

Hi,

I will try to adjust my rear turbo wastegate.

However, i have a few question for people who did it on their 1er. (Which is a bit different than 335i)

Is that 100% true that the only way to do it is from the bottom? No one managed to do it from the engine bay ?

If so, do i need to remove the plastic shield (20 screws) ? or can i access it trough the downpipes "hole" under the car?

Thanks

[xQx]

Originally Posted by studio54

Hi,

I will try to adjust my rear turbo wastegate.

However, i have a few question for people who did it on their 1er. (Which is a bit different than 335i)

Is that 100% true that the only way to do it is from the bottom? No one managed to do it from the engine bay ?

If so, do i need to remove the plastic shield (20 screws) ? or can i access it trough the downpipes "hole" under the car?

Thanks

Hey studio54,

I've got a RHD 135i convertible, with aftermarket inlets, outlets and heat shields - which is the perfect recipe for difficult-to-get-to turbos.

Lucky for me, I've also got a broken wastegate actuator arm on my rear turbo, so I've spent a fair bit of time under, beside and above my car trying to work out a way to fix it without spending $4k - $10k on turbo(s).

I can say with certainty, unlike the front turbo (which is impossible), the rear turbo does have a few avenues for access.

You might be able to get to it from the top. I can certainly touch the assembly that you need to adjust from the top of the engine bay. It's going to be difficult doing anything though, because there's stuff-all room to move, and there's a big fat heat shield between you and the job.

I'd advise you to go to the car when it's cold, pop the hood and stick a hand down there yourself to assess. You can't see a thing, but you should be able to feel the assembly without removing anything from the car. It's further back than you'd expect, lower than you'd expect and tucked in below the heat shield on that side of the engine.
Take your watch off, then stick your left arm in as far as you can go, and rest your knuckles on the exhast (downpipes), then bring your hand up and feel along under the heat tray until you can feel a rod. That's what you'll be trying to get a spanner over and twisting

From the bottom, the biggest thing in the way of access is your downpipes. Maybe removing the plastic tray gives you more access (I haven't bothered to do that), but the best access i got from underneath was actually from the road-side of the downpipes (not the engine side of the downpipes) - meaning removing tray would do nothing to improve access.

Finally, I've found the best access if you don't want to remove anything is actually from in the wheel well. On my car at least, there's a hole at the back of the wheel well which feeds in to beside, below and behind the turbo. This means, without even jacking the car up, if you turn the steering wheel as far as you can to the left, then lie on your back, you can get a hand in and fingertips up touching the assembly.

To do the actual job I'm sure you'll want the car on axle stands so you can lie under the car and get an arm in from underneath; but you might find it's very possible without removing anything if you're patient and don't mind doing the job by feel alone.

(To see what you're working on, I found the only way (unless you have an endoscope) was by looking up from the bottom through the downpipes with the car jacked up.

The "easiest" way is to hoist the car up and remove the downpipes. I'm guessing most N54 members either get very used to working under a car on axle stands or have access to a hoist. I hate the former and don't have access to the latter; so I'll go to rather unconventional lengths to do things 'the hard way' if it means I don't have to get under the car.

[studio54]

Hi xQx,

Thank you for your long & detailed answer, i really appreciate.

I managed to touch the arm with my fingers from the top, but as you said, it will be difficult to having some room to move the tools.

I will check if i have a "hole" in the wheel area.

I guess i should attach tools to my wrist with a wire/cord when doing the job

I will update if i managed to do it.