325 i vs. 325is

[fmxomar]

Hey noob question here but i always thought that the 325i and the 325is had the same motors, is this correct or am i wrong ? Reason is i came across a really nice 325i and he said he swaped a newer stock motor back in and was saying that it is different from the 325is motor. Anyways if someone could clear things up that would be great

[Mike325]

Welcome.

The motors are 100% the same. The i and the is differ in interior, exerior styling and suspension. Not too much of a difference overall, just the is is sportier and is always a 2 door. I am not sure if the i and is have different diffs or not, but the motor is the same, the m20b25.

[fmxomar]

hey thanks for the quick reply really helped out. Is there an obviously visual difference of m20b27 of the 325, 325e and 325es eta motors vs. the m20b25

[E30FreaK89]

hey thanks for the quick reply really helped out. Is there an obviously visual difference of m20b27 of the 325, 325e and 325es eta motors vs. the m20b25

the way i can tell really fast is the intake manifold..

[george graves]

the way i can tell really fast is the intake manifold..

e=Skinny intake tubes...
i=fatter

Search around, bet you can find a couple of pics and see for your self.

[fmxomar]

thanks

[E30SPDFRK]

Also the eta's have the cold start valve on the manifold.

[Fidhle007]

And a coolant expansion tank on the passenger side of the engine bay vs. the drivers side for the I motor.

[SpecM]

And a coolant expansion tank on the passenger side of the engine bay vs. the drivers side for the I motor.

-Eh... its a year thing, not engine thing. Remember that '87 325i had the old style cooling system, but a '88 s-eta had the newer style (and no cold start injecter).

84-87 pass-side tank
88-91 drivers-side tank

[SpecM]

I am not sure if the i and is have different diffs or not,

-Diffs are the same. 3.73 manual, 4.10 auto. The 'is's had a lsd standard, while regular 'i's had lsd as a stand-alone option.

[fmxomar]

thanks for all the replys. so about the lsd how would i know if it has that 'option' or not

[sticksdaman]

youd have to find a way to get under the car

jack up the rear end and look at the back of the diff there should be a metal tab hanging down with some numbers on it if there is an "s" infront of the numbers its an lsd

[E30SPDFRK]

Or just lift up the rear and spin a wheel. If the both go the same way, LSD. Sometimes the tags are hard to read on the car.

[fmxomar]

can someone post a pic of the engine bay of a m20b27 vs the m20b25 and point out the visual differences it would be a huge help because im about to check one out in a few hours

[Fidhle007]