New name and and new engine for Mina: an e30 for the GF

[Andy.B]

I did pick up his m30 swap writeup, and have read through it. I also sent an email to qbang about his mounts. Hopefully I'll be able to get to work on this soon.

[Swanny]

Give a holler to FrankM e30 since he has one of the best write ups available for the m30.

[Andy.B]

I started a new thread here to discuss the engine mount situation. I know there where some b35 blocks with dual mount provisions, but I have found no proof of b34 blocks with both provisions, yet it looks like my block has both. However, since qbang is still making b34 mounts domestically I will just be ordering his.

I'll have to send a pm to f34r to ask him some questions, since he is the closest m30 e30 I know of. Maybe I could find time to go check his out at some point.

[Swanny]

Your current ds should work if i'm not mistaken. I believe f34r had the same moving from his 2.7i to m30 build and it mounted right up.

Are the mounts that different between the b34 and b35? I figured it all just mattered for positioning not specific engine size.

[Andy.B]

Taking stock of my parts, I have:

m30b34
g265/6 with stamped steel shift carrier and large guibo output flange
e28 535i radiator
Motronic 1.0 harness/dme

which is all going into an 87 325i with a large flange driveshaft and motronic 1.1

I am planning on using the e30 engine harness to convert the b34 to motronic 1.3 by extending wires as needed and getting an e34 crank pulley/damper and dme. That should let me simplify the wiring/vacuum lines on the b34 and clean things up a little bit under the hood.

I'll re-use the e28 radiator with a pusher fan.

I'm not sure about engine mounts yet, as I can't seem to find anybody currently selling m30b34->e30 mounts in the US, but want to avoid the hassle of ordering from europe and dealing with international shipping if I can void it. I'm also unsure about which engine position I want, since I am hoping to bolt in the large guibo eta driveshaft already in the car, but am unsure if it will fit behind the g265 at any position.

The parts needed list is:
electric pusher fan
e34 oil pan/pickup
e34 crank pulley
179 dme
m30b34 > e30 engine mounts

[Andy.B]

So Mina has pretty serious rod knock, and a trashed diff that whines loudly as soon as it is warm. It got parked in the corner of the driveway while my gf drove our Miata for the remainder of the summer, while I wrapped up my 2.7i build. Now that my car is complete, I started weighing my options for getting Mina back on the road. I have another 2.7 eta engine in a garage I thought about using to slap together a 2.7i with the current head and motronic 1.1 system to replace the knocking 2.5i thats in the car currently. Having driven a 2.7e, a 2.7i, and a 2.5i throughout the summer, I can honestly say that my 274 cam'd 2.7i is my favorite engine, but I didn't love the idea of 'downgrading' a 325i with a low compression 2.7i build. I dragged my feet on doing anything with the car, so it just sat, neglected.



And I am now glad I did. I pulled home a derelict 86 535i a few week ago that my brother wanted for its minty black interior to replace the worn and weathered tan interior in his car, while I had my eye on the m30 under the hood.



After taking stock of the car and stripping out the interior and usable parts for my brother, I finally got around to checking over the engine before I made my decision on how to proceed...
Would it be a 2.7i or a 3.4i for mina?

The compression checked out ok. My compression tester is a bit wonky, with a needle that likes to stick, and a release valve that likes to leak, it took a few tries to get an accurate reading on each cylinder, but everything checked out consistently. I then pulled the valve cover and inspected the cam for damage or excessive wear, and here too, everything checked out ok.

I wanted to make the engine as easy as possible to remove, so took out the core support. (ok, the truth is that the car was so rusty I was able to bang off the core support with a hammer after I removed the bumper. It practically disintegrated in my hands.



I've got a complete m30b34 engine/transmission, along with the motronic 1.0 harness and dme, radiator, and all the associated lines, hoses, cables, etc. I disconnected everything on the engine, and pulled the exhaust and driveshaft. The only thing left holding the engine in the car is the engine mounts and gravity.



The transmission is a Getrag 265/6:



I'm not sure if that is a good or bad thing yet, as I have yet to find a clear answer as to what my driveshaft options are. Mina's transmission is from an eta, so it already has a large guibo driveshaft. I'm not sure if I can position the engine/transmission far enough forwards to use the g265 without getting the driveshaft shortened.

For the exhaust, I am planning on maintaining the stock m30 manifolds and cutting/splicing the downpipes to the stock e30 exhaust. I have an extra e30 exhaust as well to scavenge for extra pipe.



So my goal is going to be to do this swap for as little money as possible. I know there are more gains to be had by picking and choose certain parts, but I am going to work with what I've got everywhere I can. I'm hoping to actually pull off an m30 swap for the mythical sub-$1000 budget.

[Andy.B]

I got sick of the engine knock, and the whining rear diff. While considering a course of action, my brother came across an e28 535i he wanted to buy and part out for the interior...

[jd_e30]

Grr! Bummer!

[Andy.B]

Just thought I'd weigh in again here... I have done 2 valve adjustments since my last post about this topic and my rough idle seems to have resolved entirely. In fact, I tried to feel it yesterday while in traffic and couldn't. I'd say any current roughness can be attributed to a 24 year old engine/car in general. But the acute, intermittent rough idle that we were referring to has subsided. Maybe it's time for a valve adjustment for you?

Thanks for the input. The head had a fresh valve job, and I adjusted the valves right before installation, using the spring tool on the eccentrics, but I will do it again, just to be certain. I certainly hope that resolves it, as my eta with twice the mileage feels silky smooth in comparison.

[jd_e30]

Introducing: Black Betty, an e30 for the GF

Just thought I'd weigh in again here... I have done 2 valve adjustments since my last post about this topic and my rough idle seems to have resolved entirely. In fact, I tried to feel it yesterday while in traffic and couldn't. I'd say any current roughness can be attributed to a 24 year old engine/car in general. But the acute, intermittent rough idle that we were referring to has subsided. Maybe it's time for a valve adjustment for you?

[jd_e30]

Well that is not what I was hoping to hear. Maybe adjust throttle cable slightly so it idles a touch higher? 600 is a pretty low idle...

[Andy.B]

I have replaced every fuel injection sensor or control valve with new or known good pieces, and re sealed the entire head and intake. I am at a loss for what the cause might be.

[Andy.B]

I replaced the crank position sensor, ignition coil, and fuel filter today. No change. I checked every fitting and connection that could cause vacuum leak. No issues found.
I think you are right. It is trying to idle slightly too low. I am going to swap dme's later to see if that makes any difference, but I doubt it. Lastly, i'm going to adjust the valves again, but I doubt that will make a difference either.

[jd_e30]

I have the EXACT same idle situation as you. Intermittently rough. Actually, when I rev to 1k rpms it goes away, but just sitting at 500-700rpm it has that short, intermittent rough idle for a sec. Like you said most people might not care but I KNOW it should idle smoother.

My fuel filter was recently replaced, so I don't think that's your issue.


Maybe we are idling too low? In for solution!!! CPS sounds like a possibility and could also explain occasional / rare hard starts.....

[Andy.B]

I have the car in pretty good shape now. I replaced the motor mounts yesterday, cleaned and lubed the passenger front window motor that was sticking, got a new shift boot installed, and gave it a wash/wax to clean it up a bit. The car is in great stock condition, ready to start modifying, except for one little issue.

The idle is a little funky. It starts up and idles fine when its cold or warm, but after about 20 seconds, the idle gets intermittently rough. It will idle fine for 5 seconds, and feel like it misses once or twice, then go back to idling fine again. The rpm doesn't really climb or fall when this happens, and there are no codes.

I have already replaced:
cap
rotor
plugs
wires
cylinder head
all associated intake gaskets/hoses
o2 sensor
temp sensor
idle control valve
fuel injectors
fpr
dme

I have checked and verified the fuel pressure and function of the fpr, cleaned the icv, cleaned the throttle body, and replaced every single possible source of an air leak. If I remove the oil cap, the vacuum leak makes a huge difference, so I am confident there are no leaks anywhere.

The car drives great and pulls hard, and honestly, I suspect most people wouldn't complain about the idle, but I know that it should be better, especially with a freshly rebuilt head, good compression, and having been fully tuned up. For all the work I put into this car, it should purr like a kitten.

I am going to replace the fuel filter because it's one of the only things I haven't replaced yet, clean and replace the ground points on the engine, and then swap in a different ignition coil and afm to see if either of those help. Lastly, I will try swapping out the crank position sensor to see if it may be faulty. If I still have the issue, the only thing I can assume is that there is damaged wire in the harness somewhere, which I won't look forward to finding...

Anybody else ever experience a slightly, intermittently rough idle?