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Just curious at what point the turbo needs a rebuild. Mine seems to make proper boost and spool up well enough but it has oil seal leakage. I get noticeable oil at the turbo outlet, and under full boost I have white/blue smoke at the back. As far as I know its original, and the car has 180k miles on it. I'm guessing this means the seals are done for.

If I'm at the point of needing a rebuild, any recommendations on where to have it done? Not looking to change anything, just a refresh on the stock unit. If this is something I could DIY I'd be willing to give it a go but I don't want to end up destroying the thing and having to buy a whole new one.

IIRC that car didn't have any end play on the turbine shaft so if it's only seals (which I wouldn't doubt it needs) you could probably buy a rebuild kit yourself and do it.

Or, if you'd prefer not to, speak to the head of turbocharging around here, Todd @ Turbochargingdynamics. I'm sure he'd be able to rebuild that turbo for you and maybe even hop it up a bit if you'd like.

I'll check the endplay. Haven't done that yet.

If its just seals I should be able to handle that. Looks like its just a matter of marking stuff before pulling it apart so it goes back together in the same position. I just want to have a backup plan in case I open it up and find it needs more than I can deal with. I need to re-confirm the injection pump timing too. it seemed to be OK but the tool I made was a little too short and it was hard to get the dial indicator set properly. I'll knock together another one (the fourth one now) thats longer and see if that can tell me anything.

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I have an old turbo I was going to send into them but not going that route at this time. Heard good things about them from others though. Also as mentioned above, you can always ask Todd of TCD.

No endplay. I didn't put the dial indicator on it but I can feel no movement. The impeller spins smoothly, no dragging, roughness, or anything else that makes me concerned about it. I guess that bodes well for probably being able to simply re-seal the thing without any major fuss. So far its all the things I knew nothing about that have been no issue at all so hopefully that trend continues with the turbo.

I did fix the wastegate actuator. Some knucklehead had spun the rod out until the gate was always held open. Being able to make boost at low rpm vs having nothing until the motor spun up makes a huge difference in how it accelerates.

I finally found the plate though, and it makes me wonder if it is actually original. Its not a BMW dataplate like I'd expect, its a Garrett plate. If I translate these numbers out properly, it seems to indicate I have a TB03 ?

Can't get a camera in there but this is what the plate has:

1284171-0 Made In France old Garrett logo
468016-2NB2861-FTB0324

Number cast into the side above the AiResearch script is GIL3.

IIRC all the US market diesels from ford and BMW had the AiResearch turbos on them so I'd be inclined to believe it is original. Not sure if it's been rebuilt once before, the KKK27 on my car was rebuilt by the prior prior owners about 18 years ago.

I know you're looking to do a stock rebuild on this thing but with how simple the fueling system is, it might be worth it to see if Todd could fit a modern impeller in that turbo. Would look totally stock from the outside but have a bit more kick when you get on the gas.


Are you going to refit the stock airbox? (I hope that was provided with the car).

yeah, its already on there. I couldn't find an exact match for the original rubber flexy part, so its using the 524td bellows and an extension to the airbox made from 3" duct. The original Ford piece is about 2" longer than the BMW part.

I also replaced the couplers between the crossover pipe and the turbo and intake. Its using ricer-iffic silicone hose and clamps though, the BMW parts were stupidly priced. 25 for the intake side, but over 100 for the turbo side. The two parts I have on there cost me 20 bucks.

honestly it has decent pep off the line now, the wastegate is probably a little tighter than spec. The actuator broke off in the rod end when I tried to move it. I got the rod end cleared out but its enough shorter now that boost is probably a little more than stock. I only had a 10psi gauge on it last I ran it, and it hit that easily. Not popping the blow-off though so I'm not going to worry. I turned the fuel down slightly because it was hazing at idle, but the IP might be a little bit late. If it is I can probably bump the fuel back up a bit after advancing it.

IIRC 10psi is stock and 13psi is when the overboost light comes on. We confirmed that light does indeed work.

yeah I clamped off the line into the wastegate servo and it does work. Sounds like crap but I was curious if the light and gate functioned, also what it would do with more boost. Clamping it makes it pull a little more but just getting the wastegate fully closed so it makes boost at lower rpm helps a lot more.