[pud237]

Hi

I've got a late E91 with the N57 3 litre and a manual box. The engine has failed - heavy bottom end knock. Looking for advice on what I can do with this car, as I can't justify the cost of buying a used engine or rebuilding this one.

A bit of background, I own a garage and so have a full workshop available. I've been looking out for a scruffy 330d that I can buy to pull an engine from, but it got me thinking about what else I could do with this car. It's a high mileage, low spec, slightly rough looking E91 but mechanically very good - apart from the engine has just given up.

Is it feasible to use the manual box, prop, diff from this car on an auto? Can I just swap the engine ECU and any other coded ECUs to avoid having to do any programming?

Is it possible to use this box, prop & diff on an earlier 335d with the M57 engine? I was swayed to the N57 due to its better performance and fuel economy but now I know how fragile it is, I've been thinking more about the 335d. The only thing that puts me off a 335d is the auto box, I've driven a few and never been impressed. Can the 335d ECU be programmed somehow to accept a manual transmission?

Has anyone here done anything like this before?

[vester86]

if you can’t stand the heat stay out of the kitchen.
if you can’t afford to rebuild the car, despite having a full workshop at your disposal, then you shouldn’t even THINK of an 335D and swapping a manual transmission in it (yes it is possible).

read the forums, there’s tons of info regarding this subject.

[BB_cuda]

I do know that 330d with M57 can swap a manual trans into a M57 335D. I'm told the 330D diff needs to be part of the swap. This is due to the final gear on the 335D auto is a deeper overdrive than that of the 330D manual top gear. The 330d diff makes up for this with a numerically lower ratio. Doing both in the swap keeps your RPMs down on the freeway.

You need to compare the diff ratio on your manual N57 to that of what I point to above.

[ptpending]

there were no genuine MT firmware for 335d and i know the pal who did a bunch of the swaps to 335d mt and later he redone all this cars to 335d with AT, because 335d MT firmware require instant gear switching with doulbe clutch press usage and it is not possible for the average human, only for some very health people )
so the cheapest way to keep the TS car is to search for the M57D2 3.0d MT swap.
there were 325D LCI cars with M57D2 so the ECU adaptation and coding will not be so complex.

[pud237]

Originally Posted by vester86

if you can’t stand the heat stay out of the kitchen.
if you can’t afford to rebuild the car, despite having a full workshop at your disposal, then you shouldn’t even THINK of an 335D and swapping a manual transmission in it (yes it is possible).

read the forums, there’s tons of info regarding this subject.

It's not that I can't afford it, I just don't want the car to owe me more than it's worth once I'm done which is why I'm ruling out paying the going rate for a used engine from a breaker or rebuilding this one. I try to run interesting cars and break even on them over the long run. I'm not against buying a 330d that is broken in some other way and pulling the engine from it, as by the time I sell a few bits from it and weigh in the shell it won't owe me all that much. I'm not in a hurry and eventually the right donor car will turn up at the right money. But that's less interesting to me than doing something different - probably easier just to sell it as is and cut my losses.

If I found a cheap 335d with some autobox problem, investing the time into manual swapping it and being left with a potentially valuable manual 335d, I'd be up for doing it. What's a 335d needing an autobox worth? A few grand maybe? Putting a week's worth of time and the transmission from this car if I can be left with something worth £5-6k seems reasonable. I'm just not familiar with coding requirements, it'd be good to know someone in the UK that's done this before, I've only seen one guy thread of a guy in the UK that's done it but he's been banned (not sure if it was this forum or another). He was in the Wigan area if anyone knows him?

[pud237]

Originally Posted by BB_cuda

I do know that 330d with M57 can swap a manual trans into a M57 335D. I'm told the 330D diff needs to be part of the swap. This is due to the final gear on the 335D auto is a deeper overdrive than that of the 330D manual top gear. The 330d diff makes up for this with a numerically lower ratio. Doing both in the swap keeps your RPMs down on the freeway.

You need to compare the diff ratio on your manual N57 to that of what I point to above.

Yeah I was thinking if I just swapped the box & diff together, then the ratios wouldn't be any different to they are currently. I have read that using a manual box with the auto diff doesn't work and leaves you with overall too short gearing.

Does anyone know if the N57 MT gearbox, clutch, flywheel etc will bolt up to an M57 335d? If I had to source an M57 manual car to do the job then it's dead in the water, I'm only considering it because I have the bits already from this broken one.

[pud237]

This was the one, not much info though:

https://www.e90post.com/forums/showthread.php?t=1486792