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First time posting need help. I have a 1998 323ic m52 2.5L engine with a cracked head. Looking at replacing the engine but the only one I can find locally is an m52 2.8L out of a 1996 328i. Does anyone have experience with doing such a swap. Will I have problems with the 2.8L being compatible with my sensors and or computer/harness. Appreciate any input. I was told I will need to keep the intake manifold and use it with the 2.8 going in. Does that sound right. Do you think that would be the only change. I would appreciate helpful input. Thanks
 

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It should work. I would try to hold on to teh computer and harness from teh donor car. Also, do a little research on teh transmissions. I know the 328's had teh same manual tranny as the M3, and that the 323's had a different one.
 

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1. The intake manifold is identical; whoever told you that you have to keep yours is talking out of their ass: they're exactly the same. You can take yours if you feel like doing unnecessary work.

2. The mounting of the engines is the same

3. The manual transmission used in both cars is the same; automatic is different ... the housings are the same, so it will bolt up no problem, though I'm not sure how long the automatic out of a 323 would last with the extra power and torque (though I can't imagine it's life being significantly shortened by it).

4. Yes, you will need the ECU; the wiring should be identical. Keep in mind that you will have to have the new ECU re-coded by BMW to work with your car (both cars have EWS and unless you have it done, your car will not start ... normally costs around 200 dollars to have the ecu reprogrammed: I'm not sure if they need just the ECU or if it has to be attached to the car, so be ready to have the car towed if they need the car).
 

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In my opinion M 52 has one problem
he DISA valve, otherwise known as the «Intake Manifold Adjuster Unit», is located on the side of the intake manifold and is a common failure on the M54 and M52TU BMW engines. The failure is caused by the type of materials used in the manufacture of two of the three key valve components. The three key components of the DISA are the flat plastic flapper valve which opens and closes depending on engine rpm and throttle position, the bell crank lever that rotates it, and the vacuum pot that actuates the bell crank lever. The flapper valve is made of 30% glass reinforced nylon and the bell crank lever is made of standard 6/6 nylon. As shown in the pictures on the left, the bell crank lever has a male, hex shaped protrusion, which snaps into a matching female pocket on the flapper valve. These hex shaped sections are what allow the rotation of the bell crank lever to rotate the flapper valve.

During normal engine operation, vibrations from pressure pulses inside the intake manifold cause the bell crank lever and flapper valve to vibrate against each other where the hex shaped portions contact each other. These vibrations start a wear process which will cause the tiny glass fibers in the flapper valve to become exposed. Once the fibers become exposed they start to erode away the male hex portion of the weaker bell crank lever. As soon as the erosion starts it’s all down hill from there until the hex is completely worn away. The symptoms of a worn DISA valve include rough idle, lean engine codes and lack of low to mid rpm power.
If you disassemble a worn out DISA valve and look at the bell crank lever it’s common to not even recognize that it once had a hex shape on the protrusion. Once the hex is shape is worn off the lever, the flapper valve no longer opens and closes in a controlled manner by the rotation of the bell crank lever. The brittle flapper valve becomes free to slap around uncontrolled within the DISA support framework. This uncontrolled movement can lead to complete destruction of the flapper valve. The broken pieces of valve have no where else to go except through the intake manifold runners and through the motor, sometimes resulting in severe engine damage. Even a small piece of plastic broken off the flapper valve can hold an intake valve open, resulting in bent valves or much worse.

Since the only parts on the DISA valve that typically fail are the flapper valve, bell crank lever and housing seal, why replace the entire unit. Replace the failed internal parts with these DISA BMW Repair kits | Vanos BMW Repair kit Disa BMW Repair kit Repair kits for car upgraded parts and have a much more reliable DISA for 1/3 the cost.
 
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