87 325i Stutter/Hesitate

[Jimmy85'E30]

I have a 1987 325is and the previous owner has put a e head on the i block for a reason IDK. Really a pain in the butt. Anyways the car sounds like it is hesitating at high rpms and then whenever I let the car sit and or bog in 5th gear on the freeway it will stutter for a second then when i rev it up it goes away. I replaced the in tank fuel pump, sparkplugs, as well as the maf. Any iddeas!!!!!! This is my daily I need it to start running right lol


I also have a issue when I fill up my tank all the way it will leak out a good amount of gas when the car is running.. anyways thanks for the help in advance!!

[itsonlygeorge]

Previous owner probably replaced the head on the cheap or bought an e head by accident. Be careful reving it past 5k as the e head only has single cam springs, fewer oil journals, and fewer cam bearings. You really need to find a good i head to swap and preferably rebuild. The e head was not designed for high reving! I am surprised that your engine runs with such a mismatch of parts, the e head has completely different locations for the ICV and vacuum lines...

You will also need to take a look at all the rubber hoses in the engine bay and check their condition. The best way to do this is to have the engine smoke tested to look fo vacuum leaks. Start with the rubber intake boot that connects the throttle body to the intake. You should replace the air filter, plug wires, and distributor and rotor to complete your "tune up" of the motor.

As for the spilled gas, there is an access panel under the rear seat on the passenger side. Start by looking at the condition of the rubber hoses there. There is also a metal y pipe in the wheel well by the evap tank that tends to rust out. take a look under the car at the filler hose as well and really for any rubber hose that is cracked or worn out.

If you are leaking gas while driving, you are seriously risking your car and life if it catches fire.

[Jimmy85'E30]

thats the thing.. it has a e ecu as well Its a I block with a I intake and a I ICV and a I maf.... the dash is a I but it redlines at 5 the gas leak suckss I am trying to source it i find it only leaks after i fill up.. thinking that the gasket around the fuel pump may be leaking

[Cephas]

The fuel leak is very likely a rusted out tank. They tend to rust at the top and generally only leak when full. It is very dangerous and you really shouldn't drive a car that leaks fuel. That being said - a quick check of the sealing gaskets around the fuel pump and the level sender is certainly worthwhile. That's a quick and easy fix if it's the problem.

As for the engine - wow, what a mess. I'd do my best to source the ECU and head for an "i" car and get that swapped in. Did they change the wiring harness to an "e" version as well?

[Jimmy85'E30]

im not sure if the harness is a I or not. I would assume so but there is a random wire behind the head inbetween firewall so maybe.. unless its a harness and ecu out of a 88 325e

[itsonlygeorge]

Find yourself a m20b25 for parts and swap the best parts to it for a cheap rebuild. You don't want to be running that frankensteined engine. You will never get it to run right and it really is a wast of time and money to chase its problems. A reverse i to e headswap had bad juju written all over it.

[Jimmy85'E30]

i have a whole other motor... I am just going to make the stroker and call it a day. More power and a fresh motor rebuild will be nice and reliable.