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1991 525I Engine

Printed From: Bavarian-Board.co.uk - BMW Owners Discussion Forum
Category: Technical & Model Specific Forums
Forum Name: BMW 5 Series
Forum Discription: This forum will deal with any issues on the BMW 5 Series (E12, E28, E34, E39, E60 & E61)
URL: http://www.bavarian-board.co.uk/forum_posts.asp?TID=33799
Printed Date: 18-June-2024 at 12:30


Topic: 1991 525I Engine
Posted By: m5bm
Subject: 1991 525I Engine
Date Posted: 14-October-2006 at 15:50
Hi just wondering, is the 1991 525 24valve engin got the Vanos system on it ?

Or can I fit the Vanos unit to the engine if it doesn't.?


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Loving the E38



Replies:
Posted By: Andyboy
Date Posted: 14-October-2006 at 19:21
No it hasn't and no you can't!


Posted By: RedOctober
Date Posted: 14-October-2006 at 20:51

Andyboy's right I'm afraid-Vanos didn't come out for another couple of years and the cylinder head's completely different, as that's where the Vanos unit lives.

Even if you sourced a Vanos head you'll need the control unit for the Vanos and the associated wiring harness modifications etc. Also, the main ECU will be different to the non-Vanos engines.

So it's no and no I'm afraid



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"I was just clearing out the cylinders, Officer"


Posted By: m5bm
Date Posted: 14-October-2006 at 21:00
You see I have another 525i but it is the 24valve vanos and I am looking to change the engines but I would liek to put the vanos back on again.

Cheers


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Loving the E38


Posted By: RedOctober
Date Posted: 14-October-2006 at 21:32

Swapping bits from 1 model year to another model year is rarely that simple in the BMW world due to the associated electronics.

The Vanos unit sits in the cylinder head and is fed by oil pressure from a small electric solenoid valve, also in the cylinder head.

This valve controls the oil pressure to the Vanos, so needs a control unit for it to work properly, hence the extra wiring going into the main engine harness on Vanos models from this valve.

Non-Vanos models won't have either this extra wiring or the Vanos control unit, so I doubt very much it's a straight swap.

Even if you managed to make it physically fit, where are you going to connect the Vanos electrical connections to on a non-Vanos car?

The main engine ECU setting will most likely be different too, as the fuelling and ignition maps for Vanos cars will be necessarily different for non-Vanos models.

At the very least you'll have to swap the ECU, and find out how to wire in the Vanos unit to a non-Vanos car's wiring harness etc.



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"I was just clearing out the cylinders, Officer"


Posted By: m5bm
Date Posted: 15-October-2006 at 11:00
I will be fitting it into a car with VANOS already in it, the engine is alot fresher with only 90000 compared to the 220000 of the VANOS car.




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Loving the E38


Posted By: Andyboy
Date Posted: 15-October-2006 at 16:38
Oh well that's loads easier. Take the 1991 non
vanos engine, fit a complete single Vanos head and
drop it in. Or even better, buy an engine that actually
fits straight in!

Just don't bother.


Posted By: m5bm
Date Posted: 16-October-2006 at 10:36
@Andyboy

Why you being so sarcastic, I am just asking for advice on this matter cause I bought a 525i without realising that it had no VANOS on it, but the donor car that it is going into has VANOS and still has the engine in.




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Loving the E38


Posted By: Peter Fenwick
Date Posted: 16-October-2006 at 13:08

Just to clarify, you are wanting to put an non vanos engine into a vanos equiped car?

Despite Andyboys lack of tact I think he has a point. The engine itself will probably be a straight swap but fitting the vanos unit onto the non vanos engine is a total no go. On top of this you will, at the very least, need the ecu from the a non vanos car and probably the wiring loom. If the loom isn't compatible with the vanos car then it is going to get very expensive. Either way it probably isn't worth the hassle.



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Entering an age of Austerity and now driving a Focus Diesel.


Posted By: m5bm
Date Posted: 16-October-2006 at 13:16
Cheers Peter,

I never thought to check as the car I bought was a 1992 but must be very early 92.

Cheers


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Loving the E38



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