[jakeadake]

I thought I'd share my experience of R&R'ing the turbos on my 2007 335xi to possibly help someone else in the same boat. The original turbos at 135k miles had fairly noisy wastegate rattle at cold startup and consistently trigged the check engine light that corresponded to a 30FF "turbocharger pressure too low" code. After months of trial and error from replacing boost solenoids, building my own boost leak tester and securing every fitting, replacing all vacuum hoses, and even adjusting the actuators-- nothing would cure the limp mode.

I started off by purchasing the harbor freight engine support bar ~$80, this is necessary if you're not using an hoist because the subframe has to be removed which holds up the engine. I normally wouldn't trust an part from an overseas sweat shop welded by a 10yr old to carry the weight of a motor from crushing my skull, but desperate times call for desperate measures...and it worked without a hitch!



Next, I backed the car onto rhino ramps in the rear and jacked the front up and put two heavy-duty jackstands on the lifting points with hockey pucks between the plastic lift points and the jacks. This gave me enough room to work on my back under the car with plenty of room to completely remove the subframe, turbos, exhaust, steering components, etc. I also used a large wooden block under the engine just in case something failed I'd have a moment to roll out.



Here's the subframe completely removed. Not bad once you disconnect the all of the little powersteering/coolant lines that are bolted to it in the front. Then remove the two steering rack reverse torx bolts that hold the rack to the subframe and push the rack out of the back. Then unbolt the control arms and tension struts where they connect to the subframe as well as the adaptive headlight bar if you have this feature. Then six 18mm bolts hold the subframe in and it will come out.


I didn't document much from here since I was in the thick of it and pretty excited to get to the turbos to see their condition. Basically, I removed the downpipes from the turbos and midpipes, passenger engine mount, waterpump/t-stat, and intercooler. Then from the engine bay- take off the vacuum reservoirs, coolant tank, boost solenoids and bracket, and hot side outlet pipe from turbos. Then you can start prying off the turbo lines and loosening the manifolds from the block...this was the most time consuming part!


I spent about 5 hrs installing TurboLab's wastegate repair kit on the factory manifolds. You have to grind out the weld on the arm, drill out the bushing retainer, and hammer the hell out of the bushing to get it out. Then used a 20 ton press to get in the new busing, slipped the new arm in, and welded the arm and new bushing retainer pin.


At this point I put new o-rings on every line on the turbos as well as gaskets at every flange. Used the engine BMW install kit and mounted up the turbos to the block and reinstalled everything to torque spec in reverse order. Threw on a new (used) Helix intercooler and VRSF XI downpipes.



Took about 10 hrs to reinstall everything from the point of the turbos being removed from the car. Keep in mind I did this by myself with no help, so I'm sure with 2 or more people it wouldn't be as bad. Lifting the subframe on my back to get it mounted back correctly really sucked! Here's my final pic of some LUX 160 angel eyes and PIAA fogs that I threw in before bolting up the undertrays.


That's all folks, she's running now after its 4 month hiatus on jackstands in my cold unpaved garage. This gave me a hell of an introduction to BMW's, but with this experience I feel confident going forward if I have to do my own work on the car.

Also I made a 6.5 min video of the FIRST COLD START and details of the job:
https://youtu.be/Ns4-o1LHJXE

[Donutz]

Mad props to you, Sir! Job well done!

[ATLIEN]

That is pretty awesome! I am saving up for a lift of some sort as I don't mind turning a wrench but having to do so on my back and by myself is just not my favorite thing to do. Let us know how she runs with the new turbos!

[LQQKOUT]

Nice job! You don't have to completely remove the sub-frame. You can just unbolt it from the frame and let it hang. It gives you the space needed. Also take out the engine mount on the pass side. I have done it 2X like this on XI models.

[musa]

Originally Posted by ATLIEN

That is pretty awesome! I am saving up for a lift of some sort as I don't mind turning a wrench but having to do so on my back and by myself is just not my favorite thing to do. Let us know how she runs with the new turbos!

It's not that bad as it seems or sounds, really. I did by myself the turbos with complete subframe removal in addition to a complete suspension overhaul front and back, right in my garage on 4 jack stands. But it's not a job you want to do in a hurry or with time constraints.

[jakeadake]

Thanks guys. It's definitely do-able like this without a lift if you have some mechanical background because it's quite involved. Worth noting that you're guaranteed to break off exhaust studs in the head when taking the turbos off. Not a good feeling laying on your side on 20 degree wet ground trying to extract half a dozen studs out of the head. If you have a lift and a warm shop you could probably knock out the whole job in a day. Looking back I wouldn't have rebuilt the manifolds and turbo CHRAs with TurboLab's kit, too much effort and risk involved for the amount of labor to have to go back in and fix later. Also while the control arms were loose I pressed in those yellow StrongFlex poly bushings to fix the vibes I had in the front end.

Shout out to Rob's DIY guide on here- I followed that without any BMW background and it served me well. Bentley manual is far to vague and only helped out with the torque specs.

I'll let you guys know how she boosts once the roads clear up from the snow around here!

[mike@x-ph.com]

Good job

[FEDE/E92]

👏🏼 bravo sir, great job! I just did a ST kit on mine. Honestly have no idea how ppl doing from the back let alone on gravel. You sir got some big cojones lol

[Turbo_power4ever]

I did mine on jackstands too. took me a month lol... but I only worked on it 25 hrs total. I also did oil pan gasket, tensioner and pullies, inlets, outlets, new o2 sensors, new motor mounts, and had to relocate the power steering/ coolant tank and also did oil filter housing gasket. I highly recommend one of those electric ratchet things. it would of saved me tons of time ratcheting all those manifold bolts and oil pan bolts. with all the money your saving it's deff worth it.

[SE7EN335]

You might as well as replaced the whole turbos. The new turbo designs by Mitsubishi have a upgraded wastegate arm which prevents wastegate rattling for a very very long time much better than the factory turbos. But mad respect to you for undertaking such a hard task seeing as its a XI even harder than a I platform.

[jakeadake]

Originally Posted by Turbo_power4ever

I did mine on jackstands too. took me a month lol... but I only worked on it 25 hrs total. I also did oil pan gasket, tensioner and pullies, inlets, outlets, new o2 sensors, new motor mounts, and had to relocate the power steering/ coolant tank and also did oil filter housing gasket. I highly recommend one of those electric ratchet things. it would of saved me tons of time ratcheting all those manifold bolts and oil pan bolts. with all the money your saving it's deff worth it.

You're braver than I am for tackling the oil pan gasket and inlets on jackstands, that's dedication haha! I noticed some oil pooling up at the bottom of my pan that after some poking around looked to be coming from the rear main seal. It was tempting to drop the trans and fix it while I was in there, but a one man trans drop wasn't very appealing.

If these turbos grenade from my rebuild I will bite the bullet and do it again with the new Mitsubishi turbos with the updated wastegate design. I spent $300 on a set of 60k mile cores, $100 for wastegate flapper kit, $100 for CHRA rebuild kit, and $180 for turbo install kit-- so roughly a third of the the price of a new set of turbos (not counting the turbo install kit). Only time will tell if they'll hold up

[Turbo_power4ever]

dang, I bought a set of oem Mitsubishi turbos with 10k miles on em for 500$. and the replacement kit from ECS like 350$ I think. lol I also bought a new transmission pan/gasket/bolts, main seal, tranny fluid and tranny mounts at the same time too but they've been sitting for over half a year in the closet... lol I will probably do it soon and might throw in the zf thing inside the transmission, I forgot what it's called. my car has 109k miles. it's been my DD but I might retire it for my weekend warrior. thinking bout upgrading to a set of hybrids for 500-550 HP. can't afford to break my motor or tranny. lol if the frankenturbos come out for 2k I'll probably run those. my car was running fine, but I went ahead and replaced all those parts even though they were still ok because it was easy with the subframe down, and not too expensive whey you do it yourself and I hope the car will last another 100k more miles. lol maintenance is key

[Shane335]

Great job. I,m on day two of my turbo replacement on a friends 535i. getting the subframe out of the 5 series is a pain.

[shushikiary]

What did you do to extract the turbo manifold studs? I've never had success with an easy out, so I'm hoping you dont say that.

[jakeadake]

Originally Posted by shushikiary

What did you do to extract the turbo manifold studs? I've never had success with an easy out, so I'm hoping you dont say that.

Most of the exhaust studs were brittle and snapped if they were the least bit seized. Luckily every one that I snapped had enough length remaining to grab onto with vicegrips. With a good "bite" on the stud and some leverage they all came out pretty easily, but I've heard there's a common stud extractor for this purpose that reverse threads onto the stud.

I found out that when mounting up the manifolds again to the block with new donut gaskets, there's a tightening sequence that Rob's DIY suggests so that the flange and gaskets mate up to the head evenly. You'll want to have majority of the oil/coolant lines loose at the block until both manifolds are torqued down so that they'll draw up evenly.

[mojobmw_e90]

Good job! I did 2 on jack stands. Both times I took a week off from work and didn't rush them.. Not something I wanna do again that's for sure. If my current turbos fail, I will just sell the car and take my loss

[BeastMode335i]

Jackstand driveway survivor as well..

[musa]

Originally Posted by jakeadake

Most of the exhaust studs were brittle and snapped if they were the least bit seized. Luckily every one that I snapped had enough length remaining to grab onto with vicegrips. With a good "bite" on the stud and some leverage they all came out pretty easily, but I've heard there's a common stud extractor for this purpose that reverse threads onto the stud.

I found out that when mounting up the manifolds again to the block with new donut gaskets, there's a tightening sequence that Rob's DIY suggests so that the flange and gaskets mate up to the head evenly. You'll want to have majority of the oil/coolant lines loose at the block until both manifolds are torqued down so that they'll draw up evenly.

The studs need to be replaced if they're in bad condition otherwise can be just left alone. Most of mine were good and I replaced 2 or 3 which came out easily.

[Chris@VargasTurboTech]

Good job!

[YoungBlood]

the more I've considered what I'm gonna do when my turbos do go, the more I think I'm just gonna save up and keep a chunk of change set aside to pay someone to do my turbos. I'm sick to death of wrenching on this platform lol, props man

[pjr710]

Did you fix 30ff?!? Lol

[wrrush]

why not just lower the sub frame instead of taking it off, that probably added about 2 hours additional of work taking it off and putting it back on?