R3VLimited Forums - E30 Technical Forums

Steering wheel won’t unlock

Imsuperawesome — Wed, 13 May 2026 14:38:35 GMT

My steering wheel will NOT unlock. No amount of jiggling helps.
tried two different keys. Lubed the lock. Tapped with a mallet. Nothing.
has anyone experienced this before? What are my options???
thank you!

Audio Specialist in Norcal

Riverfront — Mon, 11 May 2026 05:08:54 GMT

I am currently getting my 92 Vert Repainted, once the job is done, I am wondering if there is any specialist in the Sacramento/ Bay Area that would be able to help restore my Audio System?
My original AMP was blown, and I had a shady audio shop install a sound system that bypassed the original wiring.

I do not have the technical savvy/ time to do it myself unfortunately cause of my work. Thank you

E30 M3 speedometer went dead

Del Schier — Sun, 10 May 2026 15:03:08 GMT

My 88 E30 M3 speedometer was intermittent but now dead. The odometers work and so does the cruise control. Does anyone know where I can find the schematic circuit diagram for the speedometer indicator module? I have found diagrams for the cluster wiring but not what is inside the indicator. Thanks!

Fixing dodgy wiring options

zinc — Sat, 09 May 2026 20:51:54 GMT

I recently got a 1989 325i with a stock M20B25 and ECU etc, build date is 7/1988.

I took a quick peak at the wiring under my dash and it's a horrendous mess of aftermarket alarms etc hacked in. Not even sure where to start so I'm just pretending I didn't see it for now.

Engine bay is also a mess but main issue is many of the plugs themselves have disintegrated in addition to the random unknown wires that don't connect to anything. Fuse box has also seen better days and the AC fuse melted pretty bad and appeared to have some random copper strips jammed in to make a good connection which I've fixed up and re-melted back into being servicable shape.

That said it does (or did before I took it apart) run fine despite the 37 years of people messing with the wiring.

Half considering the nuclear option of trying to rewire everything from scratch so at least I'd know what everything is, but that'd also mean it'd be off the road forever.

Original harnesses are NLA right so what are the options:

Get a donor OE junkyard harnesses in semi-decent condition (not easy to find the correct year I guess), take the plugs + sections needed and repair or replace existing harness, methodically go through and figure out what is junk somehow
Wire from scratch, maybe with aftermarket ECU, presume that would mean full engine/dash out
Cross reference with official wiring diagrams, remove anything non-standard, patch it up as best as possible and accept it as it is, if it works and isn't broke, don't mess with it too much

I want to learn more about wiring but at the same time would like to drive this thing in the near future.

Will be option 3 and pretending I didn't see it for the foreseeable till I get some engine bits done but at the same time knowing it's a mess is going to annoy me and will need to be fixed eventually.

If you can just get replacement plugs somehow that would help to patch up the existing loom and maybe will replace the fuse box. Can you get replacement plugs anywhere or is anyone making aftermarket looms for stock i.e. non-engine swapped motors?

Any feedback on new SS cat backs from China?

TimK — Sat, 09 May 2026 12:48:37 GMT

Hi all, any recent installs or opinions on these chinese mufflers? They were all over ebay for a while, my stock muffler has an annoying rattle probably from a rusted baffle. Debating whether to cut up/gut muffler or buy a cheap replacement. Would like a little more sound too, thanks in advance.

https://www.alibaba.com/product-deta...94cdd0be71b4c4

Question about emissions equipment

dice2012 — Fri, 08 May 2026 15:10:56 GMT

Hey guys. I'm installing a swap exhaust with a cat on it. I'm wondering how harmful deleting the SAP and secondary O2 systems would be for the cat long term. I am tempted to buy the SAP pump off an e36 partout near me, or rockauto, as I have most of the other parts for the system. I'd also have to figure out wiring up new secondary O2 plugs, as the guy I got the engine from just cut the wires instead of unplugging when pulling the engine.

If it's nbd for the health of the cats, I'll just do what everyone else does and flash them out of the ECU. My main concern is the cats clogging and having to pay for a new, or replacing the mid pipe.

Vert, now with mor hardtop

ehrawn — Fri, 08 May 2026 03:52:09 GMT

Scored a hardtop, finally

Vinyl is in pretty good condition but has shrunk a little and pulled away on the sides. There’s one cm long tear. Previous owner removed the sagging headliner. Hoping to get all of that repaired soon. Bonus: guy who sold it to me didn’t like my failing trunk lift struts so he installed a new pair he had squirreled away in his garage.

E30 M10 Crank Pulley Removal/Install

BadDays — Wed, 06 May 2026 14:58:14 GMT

OK so let's start this off by getting some common questions out of the way because there's not a lot of info for M10's in the E30 community and I'm getting sick of doing research and trying to remove this crank pulley off my engine for machining.

The M10 found in 84-85 318i's are not like the M10's found in 2002's, Attempting to remove the crank pulley off the engine can be done with the starter method but if your engine is taken out of the car or you took out your distributor/wiring for a standalone ecu conversion then this method can't work. The Impact method is a solid method but you do need to be careful since the engine still can turn if the flywheel isn't held down by the clutch or a screwdriver. However the impact method can work for removal if you also jam a screwdriver into the flywheel teeth before you go ham on the 30mm Bolt. Installation still requires the usage of a torque wrench set to 120 to 150 pounds respectively, Finally you can lock the flywheel itself with a small tool but this will require removing the bowl reinforcement cover (Part Number: 11141277030) and then the inspection cover to lock down the flywheel with the tool. I originally thought about removing the transmission but that's only if you're also changing the flywheel/replacing the clutch.

So what's all of this for? Essentially I'm going to add information here with pictures once I get the pulley off for machining, If you got pictures and information on how you did it, Drop it here. (M20 folks, please add your own information here as well so it helps out others when they do the crank pulley on the M10 and M20)

m20b25 turbo

Bmwb — Tue, 05 May 2026 19:16:36 GMT

ive been going at this for a while , need to know if anyone is still running a whodwho megasquirt ecu ,

ive wired both the launch control and boost controller as shown in the diagram now with my msq file the drop downs in both i dont know what one to select

pe0 - i set on the boost controller and it works in the output test but looking around people say thats for launch control which will not work when i went to t/ engine off and tried to see if it enables .. ive looked through diff msq files on his google docs but i cant figure it out or how i go about adding an output if it is missing as i did not use his msq files to get the settings dialed in and running

im going to tune the car but want to have everything correct before wasting my time and money

Stock m20b25 Turbo Mega-squirt Map help.

RonanMurphy — Tue, 05 May 2026 17:57:52 GMT

Thanks for your time in advance,

I'd like someone with someone with more experience than me (none..), to look over my tune if possible. I know there are some threads with similar topics but I'm having trouble using those to verify my maps.

This ecu was sold to me second hand, previous owner claimed that there's a startup tune for the m20 on it, this is what was on it when I first connected. I was planning on using DIY Auto Tune to work out kinks (is it actually any good?)

Okay lets get into specs:
Car: 1990 525i (yes its not an E30 don't kill me)
Engine: M20B25, sort of fresh head, ARP studs, 440cc injectors, OEM style head gasket, perhaps some blowby (leaking oil from intake)
Turbo:
Turbine Trim: 74.2
Turbine A/R: 0.63
Turbine Inducer: 64.8mm
Turbine Exducer: 55.8mm
Turbine exhaust outlet : 79mm
Turbine exhaust inlet: 44.7mm（length）/85.8mm（width）

Compressor Side:
Compressor Trim: 48.1
Compressor A/R: 0.5
Compressor Inducer: 52.7mm
Compressor Exducer: 76mm
Compressor outlet:78 mm
Compressor inlet:51.5 mm

Sorry that was a lot, don't know if its necessary but its here.

Target: For now I'm looking to go as high as possible while being reliable in the sense that it wont just blow my engine after two months, this car is a street car that I use daily for the most part. I was thinking 6-8psi.

Please let me know if there is anything obviously wrong, any general tips are welcome, post your map if it fits the specs closely enough. If you post your maps make sure to provide all the necessary information on the engine and setup.

If anything else is needed or wanted for a more informed response let me know and I'll add it up top.

Ignition Timing

VE

AFR table

Best Interior conditioner in 2026?

2mAn — Mon, 04 May 2026 19:06:35 GMT

What are you guys using today to keep the dash and vinyl door panels nice and conditioned? I'm thinking I should try and preserve mine since its not totally gone to sh!t.

ignition timing question

zaq123 — Sun, 03 May 2026 14:36:46 GMT

For those of you with larger cams and higher compression builds, what do you find the best average ignition timing for the idle is? I'm yet to put this car on the dyno to see MBT ignition numbers.. Just trying to dial in my idle as smooth as possible at the moment. does 15 degrees adv sound reasonable for 900 rpm? I adjusted ICV base in open loop to keep rpm on target ( without any corrections from PID or ignition corrections) for 15' adv. Once I introduce ignition correction of a couple of degrees (still PIDs disabled), it seems to idle ok and has 75 rpm range spread around 900 rpm target (fluctuating above/below 35-40 rpm).
So basically my idle timing is sitting withing 12-18 degrees. Does it sound reasonable for 2.9 M20 10:1 comp with ITBs and 284 cam?

Crank no start with M54 swap

clarinetnerd — Sun, 03 May 2026 01:13:27 GMT

Like the title says. M54b30 from an automatic e39. Chassis is '91 325i. DME is MS43.

Turning the key to on gets the fuel pump going, I can hear that clear enough.
Spraying brake clean (the flammable kind) down the intake doesn't help, so it isn't getting spark.
After cranking for a while (probably 10+ seconds) I can't smell any fuel, so I don't think the injectors are running either.
No fuel and no spark tells me it's probably EWS.
Using MS4x Flasher, I wrote MS430069 (with MS4x wiki's immobilizer bypass patch) onto the DME. Crank, no start. Tried it with an unaltered version of the wiki's MS43x custom firmware, which has the immobilizer bypass patch included. Same result.
MS4x Flasher shows me a half-dozen diagnostic codes:

A little poking around online gave me definitions for most of these:

DTC 113 is motor throttle valve potentiometer. That makes sense. I swapped the throttle body for an M52 cable throttle. I realize this might also be causing problems.
DTC 11 is coolant temp sensor at the outlet. Makes sense; that sensor isn't plugged in any more.
DTC 35 is the secondary air pump. Makes sense, that got deleted.
DTC 140 and 126 are evap related.
125 is for the cooling fan.
115 is "range check for throttle position adaptation". Read above (at 113) for the throttle situation.
And DTC 69 is for the fuel pump relay, which makes little-to-no sense.

Other than the throttle situation, this is a fairly basic swap, following the guide posted on this forum. I did rebuild the VANOS while I was doing everything, but I can't imagine that would have any impact.

Let me know if you need any more information.

I'm really out of ideas and I don't know where to go from here.

M20 flywheel with 24v questions

dice2012 — Thu, 30 Apr 2026 18:09:17 GMT

I'm planning on using my M20 flywheel as I already have a new clutch for it, and a new 24v flywheel and clutch looks expensive. I have read that my options are to either get the M20 flywheel lightened down to <1mm above the ring gear, or shave the e34 oil pan. I'm looking to daily drive this E30, so I have a few questions regarding everything.
Is the lightweight M20 flywheel bad for daily driving?
IF I want to go down the route of shaving the oil pan, what part do I shave, and how much do I shave off? I can't find any pictures, and I feel it would help a lot to actually see it done. Also, is shaving the oil pan risky?

Differential spec

Octarchy — Thu, 30 Apr 2026 05:03:40 GMT

Hi there ,

I am going to rebuild my diff. Its a small case diff not lsd and i am trying to find the technical spec for the diff. I am mainly after the preload and backlash specification. It would be much appreciated if anyone could help.

Thanks