M60 4.0L swap 99.9% complete- I have a few problems though!

[JKBe30m3]

I just swapped out my 3.0 m60 for a 4.0 m60 from a 93 740i. It starts and runs but it idles like it have a vacuum leak. I know that I have a bad battery and I didn't know if that was causing the idle problem considering there aren't many places to have a vacuum leak. It had the Alusil block replaced if you are wondering about that as a possible cause.

The other question that I have is that I am running the stock 3.0 dme(ecu) . I looked up the dme numbers and they are the same. I am assuming that the chips were different for the 3.0 and the 4.0. I wanted to make sure it started and the engine was alright before investing more money.


I also noticed that my shifter sits back about an inch further than it used to. The engines are identical as far as the external dimensions go and the trans bellhousing. I haven't had a chance to crawl under and look yet but I was wondering if someone else has had this problem.


Any and all help is very appreciated! Thanks in advance!!!

[BillionPa]

you do need a new chip or you will have problems, and proper voltage is required for the car to not run like its going to explode.

[bimerguycw]

I may be doing the same thing and I wonder about swapping the entire e32 740iL m60 4.0L eng with it's tranny in place of my M60 3.0L with it's tranny which is different model but may be same fitment.

Did you use your 3.0L tranny with the 4.0L and what was required.

[Barry]

You using the 30l injectors??If you are,thats your problem...