320 to 325 starting work tommorow

Discuss general engine, turbo and supercharger conversions in this section

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cruizin4dirty1s
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Sun Jan 11, 2009 10:56 pm

hi there i have an 89 bmw 320i and i got a 325i engine and box + manifolds from an 89 too was wondering is there anything i have to look out for i got the ecu to can i just plug out the old one and put in the 325 one im trying to get it done by friday took the week off work im a 3rd year apprentice mechanic so im just looking for advice more than anything

thanks for the help in advance much appreciated
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Brianmoooore
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Wed Jan 14, 2009 9:16 pm

Sorry, I've only just spotted this one, and half the week's already gone!
The 320 and 325 engine looms are the same, but it's normal to remove and install an engine complete with its loom.
The swap is quite straightforward, but if you use the (stronger) 325 gearbox, you will need the matching gear lever linkage and propshaft as well.
Unless there's evidence that it's been replaced in the last few years, I'd recommend changing the sump gasket before you fit the engine, as the sump can't be removed with the engine fully in place in the car.
Also check out very carefully the C191 plug and socket, where the injector loom joins the engine loom under the inlet manifold. Especially check under the rubber boots for corroded wires.
Take great care to fill and bleed the cooling system properly, as you rarely get a second chance to overheat a 325 cylinder head!
leeparkes
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Wed Jan 14, 2009 11:48 pm

just make sure everything is disconnected before you pull the engine out,ive heard a lot of people say they forgot the clutch slave,
it helps to lift the back of the car when removing and replacing the engine,the car sits at an angle,however this isnt necessary as ive managed it with the car on level ground,
it does help to have 'a mate' around to help you,trust me ive had my wife in the past trying to fathom out an engine hoist while im guiding an engine in (only happened once but never again) it helps if your mate is quite handy with a spanner (and strong)
its not rocket science and it works better when its planed,do one job at a time,and make sure you have all the tools you need.

good luck

p.s. cool user name winkeye
Cypriotgeeza wrote:I done both my mates in my old 318is
felt so proud,even tried it with a E30 325i and got put in my place.. :o:
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renoops67
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Sun Mar 01, 2009 9:45 pm

Hi iam also doing the same my 320 is older it is a 1984 no abs the 325 engine & box is a 1989 with abs will it go in the same?
Having the back of the car up when removing the engine does this mean the engine & box come out together?
Also if i left the 320 back diff in would this give me more accceleration or top end & would it be strong enough
clarko74
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Tue Mar 03, 2009 1:11 pm

It's easier to take the engine and box out as one unit and as Brian mentioned above the 325 box is stronger.

My 320 has a 325 engine in it with the original (4.1 I think) diff. It does accelerate well but I find that 1st gear is so low that it's not a great deal of use and at motorway speeds the high revs can become a bit tiresome. I've heard that the small case diffs don't handle the power of the 325 very well, mine is fine but the 2.5 has only been in it for 6 months. I'm going to put a 3.64 diff into it when I do the rear brake conversion in a couple of weeks.
clarko74
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