Which Terrible E36?

I impulse-bought two E36 2drs. Both 2.5L 6cyl/5spd manual. They're pretty close to equally terrible, so I'm not sure which one is the "good one" and which one is for parts. That's where the GRM Braintrust comes in...

Car 1: 1993 325iS, 2dr, white, horrible (tan) interior, door windows don't work, missing transmission. Car 2: 1998 323iS, flat black, near-mint (black) interior, almost nothing electrical works but car is complete. Was converted by PO from automatic to manual and now won't rev over 3000RPM. Problem seems to be electrical (gas pedal inputs are not translating into throttle blade movements. Car has drive-by-wire throttle. Dash was clearly out of car at some point, now fits poorly, obscures VIN tag and nothing works (radio, climate conrols, etc). My goal is a cheap weekend track toy that I can drive to work M-F. So, my options seem to be to either swap the transmission and nicer interior from the 323 to the 325 or to chase down the 323's myriad electrical gremlins. A more complicated option would be to convert the 323 to OBD1 using the 93 325iS as a donor (both cars are 2.5L 6cyl). The bodies of the two cars are about equal. When I bought the two cars, my intention was to fix the newer car with the electrical issues, but now i'm reconsidering because I'm far better at swapping mechanical parts than fixing electrical problems. What sayeth GRM?

Keep #1, pirate all you need from the #2 car.

It seemed pretty simple when I read your description but of course that's using my bias and my limited talent/patience.

Agreed. I would much rather swap out a tranny and some window regulators (assumptions ftw!), than deal with an electrical basket case with flat black paint.

Eeks. How much did you pay for them both?

In reply to nderwater:

I paid +/- challenge money but I also got a hideous two-tone, red & black 94 318i that runs, in the deal. I'll probably de-ugly the 318 and sell it to fund the coupe project

We have terrible E36 M3 to add to your collection.

In reply to Tim Suddard:

I tried to put pics up in reader's rides but it keeps telling me the file is too large, no matter how many times I cut it down with Irfanview

I agree with #2 == parts car, fix #1 strategy.

Then, gut #2, cage it and find S52/ZF trans to make race car.

Which one has the least rust/body damage?

In reply to eastsidemav:

They're about the same

Something is very wrong or you are not being told something if that '98 has a DBW setup, because that was an introduction for '99 on the E46 cars....

He could have used a '99 manual ECU and wiring to convert it to manual because maybe he had a '99 parts car. That could also be why it doesn't run right.

Part out second car for cash, buy M3 motor, put into first car.

SlickDizzy wrote: Something is very wrong or you are not being told something if that '98 has a DBW setup, because that was an introduction for '99 on the E46 cars....

Is it possible it was a 'tweener' car? I thought the 323i used a 2.5l M52 (the 328s used the same M52 but with 2.8l displacement), and that same 2.5l M52 powered the later e46 325i? Is your 323i dual vanos, or just single?

If it was an engine swap (like slick suggests), check to make sure the 323i block isn't aluminum. z3s came with aluminum blocks, so there is a chance. if that is the case, you might want to look into swapping the ODB-1 stuff (I believe the intake manifold is the biggest gain) onto the 323i block for a 40-50lb lighter package.

That said, the 98 323i was rated stock at like 170 HP at 5500 and the 93 325i was rated like 190 HP at 5900. BMW needed to differentiate the 328 from the 323, so they might have 'optimized' the 323 cams toward fuel efficiency too. Though both the 325 and 323 have the same displacement, one was the 'big' engine and the other was the 'little' engine for their respective model years.

Also, I agree with putting the trans and nice interior in the older car. Check the rear subframe mounts on both to see if either car is ripped.

I am officially in the BONUS ROUND!!! Turns out the hideous black & red "318i" is, in fact, a 325(!)

In reply to rcutclif:

To my knowledge the only in-betweener would be a '99 coupe, and even then I'm not sure. The cutoff of non-TU engines coincides with the beginning of E46 production; likewise, no parts book on the internet lists the MDK (BMW motor-driven throttle assembly) as E36 compatible for any model year. Single/dual VANOS would be the giveaway.

BMW made a handful changes with the switch to OBD2 in '95. As you note, the OBD2 engines have an intake manifold that flows much worse but provides greater torque, swapping to the earlier one unlocks a lot of that lost power. The rest is largely in the tune and shorter rear end gears (2.8 cars had taller gearing). I've not heard of any other major differences.

If you can dig out the vin from behind the misaligned dash, run it at realoem.com. It will tell every spec part and system that the car left the factory with, including diagrams and part numbers.

If I was going to track any 6 pot motor from the M50/M52 family, I would overbuild the crap out of the cooling system. That or keep a refreshed head, gaskets, and bolts in my spares locker. I would also refresh my knowledge of VANOS failure and replacement procedures.

Good luck with your project, though. Most of the BMW club instructors down in my neck of the woods love the E36 chassis, once it's sorted out and the understeer is dialed back. I'm working on one myself this summer, albeit with Ford 302 power.

325i 4dr automatic just became a parts car because rusty floors and limited slip

M030 wrote: 325i 4dr automatic just became a parts car because rusty floors and limited slip

Sweet score on that limited slip. Should be a 3.91 if its original. Will make your manual car (stock 3.15) a screamer. But you will probably have to shift to 3rd in autox...

http://www.bokchoys.com/differential/GearRatios.htm

323 definitely has an iron block. It's also mint underneath. I'm leaning toward OBD1 Swapping the newer car & grabbing the 93 325iS manifold while I'm at it

Post some pics of the throttle body on #2. I'll bet you don't have drive by wire and are seeing the ASC/TC unit. No one is going to backdate an E36 with a drive by wire set-up unless they are installing an S54. I know a couple of people who have done this, but AFAIK you need a special wiring harness for this available from APEX.

just out of curiosity.. those year BMWs used a separate eclectically controlled flap for traction control. Is that what you mean by DBW and is it either stuck or activating prematurely due to bad wheel sensors?

E36 wind regulators get a bad wrap when the only problems are plastic slides and bad grease. Get new slides and clean out -all- of the old sticky grease and replace it with new slippery stuff. Windows will work beautifully. Not sure what BMW used for grease on them.. but over time it goes from slippery to sticky with all the window regulator carnage you can image

In reply to mad_machine:

Thanks! While I'm in there, can a window motor from my 4-door parts car be re-purposed for use in the 2-door?

I tried looking on Realoem but they have the motors grayed out. I guess they are currently unavailable

I can only suggest you take them both out of their respective cars and give them a good look over

It just occured to me that the 323 that won't rev over3000RPM had the problem before the PO swapped it from auto to manual. In fact, he said he swapped it because the auto trans was defective. I bet it was misdiagnosed. Opinions?