VANOS engine fit a non-VANOS '91 525i?

[joebigfun]

I just bought a '91 525i with a bad engine. Curiously, it looks like it will cost me more for a '91-'92 non-VANOS engine than it would for a '93-'95 VANOS engine. And my Hollander interchange book (the one the junk-yards use) says they are interchangeable. I would imagine if there wasn't an ECU signal to the VANOS it might not make any difference. Anybody out there with experience with doing this?

[MarkD]

I just bought a '91 525i with a bad engine. Curiously, it looks like it will cost me more for a '91-'92 non-VANOS engine than it would for a '93-'95 VANOS engine. And my Hollander interchange book (the one the junk-yards use) says they are interchangeable. I would imagine if there wasn't an ECU signal to the VANOS it might not make any difference. Anybody out there with experience with doing this?


You need the proper DME and most likely the wiring harness, as the earlier motors don't have knock sensors. There's no point running that motor without the proper wiring and DME.

Mark

[winfred]

theres a couple differences, knock sensors on the vanos and not on the non, and the wire triggering the advance of the vanos unit. i stopped counting all the little tidbits of wrong or slightly wrong info in the manuals. it'll go in but you should get the harness and brain, and on the harness check out the connection by the heater valves, they swapped the wires around in the plug every couple years (been bit in the ass a couple times by that one) usually ac crap

[joebigfun]

But I'm thinking the DME and harness don't have to be swapped. The knock-sensor will be unused (same as not being present on the original motor), and the VANOS will just stay fixed. That must be what the Hollander guys think too. Ideas?

[winfred]

that would likely suck, the vanos is a milder motor, it has less lumpy cams, it makes up for this with the 3-4k intake cam advance. the non vanos is a hotter motor. i doubt they are talking about leaving important equipment like a advance unit unhooked, if they are they suck more then i gave them credit for, i have a couple sets of hollander's and learned to not lean on them too much

[joebigfun]

OK, that sounds reasonable, if the cams are radically different. They only mention oil-pan/exhaust manifolds as being possibly different (between 325i and 525i '91-'95). I have seen some issues with Hollander, but usually they err on the safe side. This would be the first time I saw an error like this. Thanks.