[AviCrux]

Hello everyone, so story to go with this question. I purchased a 2011 335IS Mid-December. Really loved the car sounded and drove great. This wasn't my first N54 or E9X car, so I'm familiar with the issues on these cars. Right off the bat, before buying I knew the car had an OFHG leak. The entire front of the engine was greasy and oily, and the serpentine belt was really chewed up. I bought the car for $6000 at 122,000 miles clean title. despite the high mileage and noticeable issues. I felt I was still getting a fair deal. The car was rare, and the issues where alarming but relatively simple and inexpensive.

Not long after buying I scanned the car with the Carly OBD2 scanner, and discovered the vin on the engine did not match the vin of the vehicle (bear this in mind, this is important), and actually the engine was produced in 2008 for an E60 535I. This was a bit daunting, because this essentially meant the car did not have an actual IS engine, which is slightly different than the N54 on the regular 335i/135i/535i/Z4S35i vehicles. The engine on the IS had more kw power at 240kw compared to the 225kw. I wasn't certain if the extra kw made any difference, but it was too late. I had already bought the car by the time I discovered the issue, and even if I did, the previous owner was not willing to discount the price any further than what I purchased it for.

I decided to just let it go and just enjoy the car and fix the issues it had. which i did, for like $300 I replaced the pulleys, serpentine belt, and OFHG's. The job was really simple and I've done it before. The car ran practically perfect after that and some general maintenance. I really enjoyed this car while i had, up until recently.

Unfortunately yesterday, on my drive home from work, my dash indicated Battery charging malfunction, thought it was weird as the car hadn't had any signs or electrical problems recently. Not long after that I was met with a loss to power steering. I didn't immediately connect these issues until way later. At the time of this happening i was roughly 5 miles or 20 mins from my house. I decided to just ignore these issues and get home then inspect for issues or refer t the forums for details. however when i did my heart sank to discover that these where signs of a broken serpentine belt. Immediately I opened the hood just to see the belt in pieces. Assessing the amount of time I drove my car, I highly believe the belt got sucked into the engine. The car is still parked, and I haven't touched it since. I haven't had time to inspect, but regardless I'm already assuming the worst. Therefore I'm considering getting a new engine for my car.

I realize the engine is likely not blown. In fact I know it isn't but i will have clean out the camshaft and drop the subframe to check the oil pan. But part of me is looking at this event as positive because now I feel I have a valid excuse to replace the engine with an authentic IS engine. The fact the car has an engine from an E60 always bothered me, but there wasn't much I could do. The engine was healthy and I didn't have any reason to justfiy spending a large portion on changing the engine. But now i feel i do. Unfortantely I could not find an engine from another 335is online. but I was able to find a few from the F01 740I 2011-2012. and according to sources its the exact same as the 335is one. But I am not certain if I can install one of those engines in my car.


I'd like an answer to my question please if anyone knows. And I'd also like jsut general advice or recommendations on what I should do moving forward with this car. Should i even bother changing the engine, or just fix and sell, or just part out, or just sell as is for mechanics special?


Also if anyone is by chance knowledgeable on decent places in southern california that will do an engine swap or knows anyone that has a used IS engine, please lmk.

[feuer]

How can Carly OBD2 scanner give you info on the engine? I don't think that is possible. There is a label on the back of the engine that will give you the VIN of the car it came from. Carly OBD2 scanner can not do that. Power difference comes from different program the IS is running and most aftermarket tunes are better that the IS program anyhow. Engines have some different parts, like, rear turbo, rear turbo inlet, and crank hub to mu knowledge. It was $6000 335is. Be happy you got it. Fix the current issue and forget about swapping the engine. That is my advice to you. Especially that you can not do the work yourself. Used engine swap is costly. It might cost you as much as you got this car and you don't know what problems will come from that used engine you are throwing in. Might be worse than the engine you have in there now.

[clegg]

I would also inspect and repair the existing engine.
I am wondering how the new belt broke with all new parts installed? I would check the power steering mounting bolts and motor mounts.

[Knerr]

I would more likely suspect your DME was replaced. Not the motor. There isn't a sensor on the motor that would tell the reader that information, but the DME would.

I know DME issues are rare on MDS81 cars, but on this platform... nothing is safe.

It's definitely worth your time and money to have your current motor cleaned and resealed. Like Fueur said.. at least you know your current motor is healthy. buying used is a risk in its self.

Otherwise, as far as I know, an N54 is an N54. It's the accessories that are different

[Emilime75]

Unfortunately, an E92, 2011, 335is reporting back as an E60 535i that was bought for 1/3 the going rate - likely means you have no idea what was hodge-podged in this thing.

Does the VIN come back as an is? What's the CarFax say about it? Isn't the DME supposed to be coded with the VIN of the car, or it won't start...did someone also swap out the EWS/CAS along with the DME? Is that even possible?

[feuer]

Originally Posted by Emilime75

Isn't the DME supposed to be coded with the VIN of the car, or it won't start...did someone also swap out the EWS/CAS along with the DME? Is that even possible?

VIN can be different and still work if ISN sync is done. Mine MSD81 on the 2008 335i is done this way.

[Knerr]

My DME VIN does not match the vehicle's VIN and I have no issues.

[Emilime75]

Good to know.

[AviCrux]

Yeah I just used the “Used Car Check” feature in the Carly app. Lol I used it after I had already bought the car, so wouldn’t have made a difference anyway. But I was curious. And just what came up was that the engine build date was 07/04/2008, and the vin of the engine was WBANW13578CZ82165, which apparently comes from an E60. The car is a clean Title, although it was involved in a front end collision about 8 months prior to me purchasing and from what I ready on car fax the damage was minor, and the prev owner showed me pics, where it was just the bumper that was just a fender bender. I would like to say the DME was actually swapped out, and I know because the owner gave me the original one when I bought it. And that could be why Carly gave me a different vin from the engine. Possibly? And yeah I knew the car condition walking into this, and I pretty much accepted all risk.

Yeah I did think it might just be better to clean out the current engine. I know that even if I wanted to replace the engine, I wouldn’t be able to tell if the replacement engine even came from the car advertised as donor or if it actually had the mileage advertised.

The only reason I would even want to replace the engine is just so I can get one with lower mileage(hence more life), and get a more powerful version of the N54.


And yeah I was bummed out that despite taking the preventative maintaintence and repairs, the belt still ripped. I believe the reason is because the OFHG was still leaking oil. I only suspect because I removed the bolts connecting the oil cooler hose to the OFHG, and the bolts fell into the engine bay and there was no way to fish em out. I looked online a long time to see if there was replacement bolts on sale, but there was not. I used bolts that fit the thread patter roughly and for the most part it secured the oil cooler lines, but maybe it still leaked oil.

I really appreciate the advice from everyone. Still just for general knowledge can anyone please confirm if the 2011-2012 740i n54 Engine be put into a 335IS or even 335i?

[feuer]

Lol lower mileage doesn’t mean longer life. Doesn’t mean anything. It irritates the hell out of me when people use mileage in such references. It matters how it was utilized and maintained lot more than mileage.

[feuer]

To answer your question: yes! Any n54 for that matter.

[Knerr]

Gonna say it again.. there is not a "more powerful" N54. It is purely software. your 335is motor is physically the same as the N54 in any other car. Some have differently clocked turbos or other stuff, but the motor is no different.