88 2.5 in a 86 325 need help - BMW Forum

87325 · 05-10-2009, 10:55 PM

I just bought a 1986 325e that had a 2.7 in it.Guy swaped a 88 2.5 out of a 325is question is will the computer that is under the dash run the 2.5? Or will i have to run the 2.5 ecu?And will the factory harness work since the 2.5 ecu plugs right in the 86 2.7 harness?Any help would be appriciated.Mark

witeshark · 05-10-2009, 10:59 PM

AFAIK, the 2.5 ECU would be recommended. Note: moved to the E30 section.

87325 · 05-10-2009, 11:01 PM

So i can use the factory harness since it plugs right in?

witeshark · 05-10-2009, 11:02 PM

I don't know that for a fact, but it seems likely. If not, most likely some new connectors would sort it out.

87325 · 05-10-2009, 11:05 PM

Well he said the 2.5 and the 2.7 was very similar engines.I have the 2.5 harness as well but if i didnt have to change it i wasnt going too lol.Know what i mean.Thanks

witeshark · 05-10-2009, 11:24 PM

They are very similar M20 variants. More than likely, the connections are the same; only the ECU needs to match the 2.5 higher performance M20.

87325 · 05-11-2009, 05:48 AM

Ok ill change the just the ecu under the driver side dash.And see if that will work.Any idea how the headlights tie into the main harness? I got the car half way thru a swap guy got tired of messing with it so im trying to finish it.Thanks

87325 · 05-11-2009, 01:01 PM

ttt

87325 · 05-11-2009, 06:39 PM

ttt need help

silversled · 05-11-2009, 07:51 PM

what are you saying? does the car even run? does it exist? this sounds a
bit odd to me...

87325 · 05-11-2009, 08:22 PM

What about it is odd? No it dosnt run thats why im here asking questions about the wiring so i can get it running.

silversled · 05-11-2009, 09:01 PM

only reason is that what you are asking about is a major project that I would reckon many DIY kind of guys would even attempt. I wouldn't and I have converted/swapped a 1974 2002 engine (automatic trans) into a 1976 2002 body (4 speed). That was not easy and these were 2002s, comparatively nothing electronic. I would say that, without looking into this in more detail,
is completely unfeasable financially, if even technically.....good luck though...keep us posted on this baby....cliff

87325 · 05-11-2009, 09:13 PM

The car bodys are in the same,The engines are pretty much the same from a 2.7 to a 2.5I mean the engine is a 88 model And the car is a 86 model not much diffrence.I have a complete harnesss,ecu,out of the donor car,I WOULDNT SAY ITS UNFEASABLE.Im just wondering if i can run the 2.5 engine threw the 2.7 engine harness while just pluging the '88 2.5 ecu into the 2.7 harness?Thats the only thing i need to know.Anybody done this swap? That can help?

87325 · 05-23-2009, 11:26 PM

ttt

witeshark · 05-23-2009, 11:36 PM

If it's just literally wires, connectors and harness, I don't see why not.