A common cause of a jumpy and inaccurate temperature gauge needle is a loose ground or a short circuit in the instrument cluster. However, because the e30 has a real temperature sender that isn’t buffered or averaged out it’s prone to some erratic movement as warmer or colder coolant passes through the thermostat housing.

The jumpy needle can indicate a loose ground in the cluster, a fault in the wiring harness or might even indicate a cooling issue such a failing head gasket. I swapped in a performance radiator because I wanted to ensure maximum cooling but to solve the jumpy needle I needed to check the other possibilities.

bmws e30 temperature gauge normal

Above: Generally considered ‘normal’ e30 running temperature.

When troubleshooting anything I always start with the easiest, simplest solution just in case it proves correct. In this case that’s the ground on the temperature VDO gauge. I decided to check it, and do a few other cosmetic things on the cluster while I was in there:

  • Find and tighten the ground nut on for the temperature gauge.
  • Replace the missing Anti-Lock bulb to help further diagnose my non-functioning ABS.
  • Replace the plastic gauge rings the PO added.
  • Touch up the red needles the PO painted.

Temperature Needle Ground Nut

After removing the cluster I used a 7mm screwdriver socket bit that I got with a euro toolkit to tighten the nut. It’s not a common tool so you may have to buy a thin wall socket just for this job. On my cluster it appears that someone already tightened the fuel gauge nut but used some pliers which damaged the plastic around the nut. The PO is always the worst person.

BMW e30 rear of cluster showing temperature gauge nut to tighten

Above: The brass temp gauge ground nut is next to the blue plug.

I used light pressure to tighten the nut until it felt about as tight as the fuel gauge nut. The cluster is mostly plastic so over tightening would be a terrible thing. I’m happy to report that it looks like this has fixed my jumpy temperature gauge entirely.

Anti-Lock Bulb

Replacing the bulb is straight forward. Now I need to diagnose my non-functioning ABS which is causing the bulb to light. In the above picture the anti-lock bulb socket is just a plastic hole. The bulb is actually attached to the harness. More on that in another blog entry.

Gauge Rings and Needles

The previous owner put ABS plastic rings around the instrument gauges and even though they are kind of ricey I admit that I’ve grown fond of them. I ordered two sets of real metal rings from Bavarian Restoration (I ordered mine via R3vlimited): polished aluminum and brushed metal. The brushed metal appeared to bright to me so I opted for the polished aluminum.

Bavarian Restoration chrome and matte cluster rings on BMW e30 instrument cluster

Above: Polished vs matte cluster rings.

Fitment of the Bavarian Restoration rings was excellent and required only firm, even pressure to snap into the cluster. While I had the cluster I also used some red Sharpie to touch up the PO’s sloppy paint job on the gauge needles.

Using sharpie to paint e30 gauge needles red

October 8, 2014 cosmetic

My windshield has always been so pitted that I couldn’t see when driving into the sun. After a chunk of dry wall fell off a truck and left a scratch directly in front of my view of the road I decided to call Safelite and have it replaced.

Total cost for the window with installation was a mere $275 and I saved a little bit by reusing the window weather strip. The black metal spacer (called a cup) and the flexible metal trim are always reused.

I was very impressed with the window tech’s knowledge of european cars and we talked about e30s the entire time he was working. I was especially interested in his technique for replacing the metal gasket which you can see in one of the photos below. I’ve seen this done with soapy water and hand pressure but the diamond shaped loop tool he used made it look easy.

BMW e30 windshield metal cup or spacer


bmw e30 with window removed


BMW e30 using a tool to fit the trim into the gasket

April 30, 2014 cosmetic, repairs

I found some cheap but apparently good condition all-red tail lights and picked them up. They have no markings on them and the clear coat seems good. Installed these and a UUC clutch stop this morning.

bmw e30 all red tails tail lights

bmw e30 all red tails tail lights

bmw e30 all red tails tail lights

bmw e30 all red tails tail lights

October 23, 2013 cosmetic

I need to reduce my e30 parts cache so I’m selling some things. I’ve had my OEM tail lights in a box for the last 6 months and decided to put them back on and sell the all red junkyard tail lights.

BMW e30 with red tail lights
BMW e30 with factory OEM tail lights

Here’s the junkyard reds: selling them go for $40.

BMW e30 late model all red tail lights
BMW e30 late model all red tail lights
BMW e30 late model all red tail lights
BMW e30 late model all red tail lights

June 19, 2013 cosmetic

A month ago I replaced my BMW MTech I steering wheel with a Momo Mod 7 wheel that provides enough room between pedals and wheel to fit my legs when applying heel-toe. It came with a Momo horn button but I bought a BMW horn button from an Amazon retailer for $20. Unfortunately the colour of the emblem is not even the correct shade of blue.

I decided to use the stock Momo button until I could find the real deal. A search revealed that Momo did make horn buttons with emblems licensed by BMW at some time in the past but I couldn’t find one for sale. Searching BMW forums turned up only dead ends except for one thread on Bimmerforums that contained a lead.

I took a gamble and contacted a user by the name of “vapor”.

Vapor travels back and forth between the US and Japan every few weeks and works his connections overseas to get rare parts. Communication was sporadic: It took a week to hear back from him. He might be going to Japan with a small stop over in the US at which time he could mail the package. It wouldn’t be cheap. He’d contact me later.

Then nothing for 3 weeks until I got a message that the package was in the mail.

Real Momo BMW Emblem Horn Button with Reproduction Version

The authentic Momo BMW horn button differs from the reproduction item in a few notable ways:

  1. The real deal has “MOMO” embossed into the plastic on the back of the button.
  2. The bezel is matte plastic with a shiny black ring around the BMW emblem. No excessive fake chrome.
  3. The emblems has the right colour and is sealed in resin. There is not texture to the emblem.
  4. The real deal also has only one wire for connecting it to the horn circuit. The circuit is completed by grounding out via the horn ring.
  5. Back of Momo BMW Horn Button

    My Mod 7 steering wheel is not “period correct” for an e30 but it’s a cheap and functional wheel. The addition of the BMW horn button makes it seem to belong a little more.

    BMW e30 with Momo Mod 7 Steering Wheel and BMW Momo Horn Button

June 2, 2013 cosmetic

After 20 years of being in the engine bay of an e30 any kind of plastic starts to… look like a cross between dried snot and old cheese. The coolant reservoir suffers the worst because without regular flushes the contents turn slimy and seep into the plastic.

Of course this in no way impedes functionality so replacement ranks low on the priority list. I’ve read that some (ABS) plastic can be bleached in peroxide and regain some of it’s original appearance but that can take weeks and produce marginal results. In most cases DIYers choose paint over replacement.

I’ve collected the following example photos of painted engine bay plastics for example:

My e30’s own coolant tank was especially pathetic. In addition to being cat-vomit brown it had picked up some overspray from the PO’s paint job and accumulated a thick layer of sludge in the bottom. The washer fluid tank suffered the same overspray but I painted that blue which I think really sets off well against the rest of the engine bay. I decided not to paint the coolant reservoir because I don’t have a space to paint in right now and it’s impossible to read the coolant level once painted.

During my engine swap I needed to fill out an order for some small parts and decided I’d add the tank to the order. I didn’t take any photos during the install but it was pretty straight forward and I think the results are nice.


1989 BMW e30 325i Clean Engine Bay and new Coolant Reservoir

e30 Coolant Reservoir

Coolant Reservoir Replacement

  1. Disconnect the Air Flow Meter and remove it along with the air box that holds the air filter.
  2. Put some cardboard and catch pan under the radiator and remove the lower drain plug.
  3. As coolant drains remove the cap from the overflow reservoir.
  4. Disconnect and remove the coolant level sensor by loosening the large black nut that connects it to the reservoir.
  5. Remove the coolant return hose from the bottom of the reservoir and immediately move it over the catch pan to drain.
  6. Cut off the radiator to overflow reservoir hose very close to the hose clamp, or cut the hose clamp off.
  7. Cut off reservoir overflow hose that runs to a hole in fender.
  8. Remove the old reservoir by pulling up to release it from the clip holding it to the frame.
  9. Put in the new tank, reconnect the hoses.
  10. Use either a very small worm-gear hose clamp or use the OEM “Oetiker Clamp” and end nippers (in lieu of the proper pliers) to connect the high-pressure radiator overflow to overflow reservoir hose.
  11. Refill the system with coolant and bleed it of any trapped air. This is well covered elsewhere in more or less detail.
  12. bmw e30 coolant reservoir

    Parts List

    Radiator Expansion Tank 17111712641
    Hose Clamp 32411712735
    Oetiker Clamps and Pliers on Amazon

May 26, 2013 cosmetic, mechanical

According to many the stock BMW Mtech I steering wheel is the cheapest, best steering wheel for any e30. It’s period correct, sized so that it does not block the driver’s view of the dials and has 3 horn buttons which can be pressed without ever taking your hand off the wheel. It’s perfect for everything including city driving and spirited back road hoonage.

For all those reasons I put off, and put off, buying a new steering wheel. But on May 4th I’ll be participating in the BMW CCA GGC’s HPDE and I felt it was time to update my wheel. The biggest motivator is that there is not enough room for my leg between the wheel and gas pedal when heal-toe braking / blipping the throttle. I’m only 6’1″ but I have to twist my leg in a weird way that just barely works and is generally clumsy. As well my old wheel has no leather texture left and is unpleasant for long drives without gloves.

Admittedly I bought a new steering wheel based on looks and community opinion of the manufacturer. I’m becoming a rally racing fan and the yellow center marking on the Momo Mod 7 has big appeal. Because I was already placing large orders for M20 parts I decided to just add a wheel to my already huge order, save a couple bucks on shipping and just go for it. I put the wheel on this morning and drove to work only once but I can already feel that the light weight and smaller diameter makes the wheel easy to turn and grips nicely.

The BMW horn button is after-market and hard to find. Initially I was searching enthusiast forums but found an inexpensive plastic version with the perfect fitment on Aamzon for less than $20. Links for all items are below the photos.

BMW e30 Momo Mod 7 with BMW horn button


BMW e30 Momo Steering Wheel Installation Instructions
Momo Mod 7 Steering Wheel
Momo e30 Hub Adapter
BMW Horn Button for Momo Steering Wheels on Amazon

April 22, 2013 cosmetic, guide, interior

Of all my e30’s broken and missing bits the hardest part to source has been the sunroof crank. It was replaced just two weeks ago after almost a year of searching. I bought at least 4 assemblies myself and a friend who ultimately found the right crank brought me 3. Granted part of the problem is finding a crank that’s complete and not broken but fitment was part of the problem too. For the money spent buying used handles I may as well have bought new but now I’m far more knowledgable about e30 sunroof cranks. And I’m going to pass on everything I’ve learned to you.



Regardless of vintage BMW lists only one part number for the sunroof crank — BMW Part Number 54121859594. I’m not sure if BMW has developed a universal part or if this is an error: forum posts and personal experience indicate there are 2 styles of handles and they are not interchangable. The photo below shows the two different handle stlyes (without knobs).

The crank I’ve identified as “early model” is on the left. It’s wider and the knob post is taller. The “late model” crank is on the right. It’s important to get the right handle for your car.



There are essentially 2 styles of knobs and usage depends on the knob post design, again divided by early and late model e30s. I would illustrate the differences with photos but I destroyed most of the knobs trying to separate them from handles (more on that later).  I can’t even find any pictures on the internet so we’ll have to make do with my 3D render:


Early Model Crank (Left) 1987 and Earlier
The early model sunroof handle has a plain knob that does not spin when you turn the handle. This is a poor design and I’m not surprised BMW engineers changed it. The knob is pressed onto a tall post and will crack if you try to remove it, even more so if it’s hot. If you are missing the knob you will likely need to replace the entire crank because the knobs are just not removable.

Late Model Crank (Right) 1988 and Later
The late model sunroof handle knob spins when you turn the handle and has a 2 part construction that manifests with a button-like depression on the top of the knob. The knob can be removed from the handle using warm or hot water. I’ve never cracked one of these knobs though there is some kind of glue inside the knob that can be messy and crumbles under heat. If you have a knobless late model crank you can probably find another one.

Crank Fitment

The crank attatches to the sunroof gears via a post. My old handle slipped on and off the gear post easily but when I finally found the appropriate replacement handle it was a very snug fit and required wiggling and pushing to install. I’m never taking it off now!

The hole looks identical between early and late model cranks but I believe they are yet again different. The hole and gear post are subtly keyed: one side of the hole / post is shorter than the other. You must align this to the gear post or it won’t fit.

The two styles of crank combined with this sneaky keyed design have stymied lots of people, according to forum threads I’ve read.



That’s it. I haven’t done a step by step removal / install because it’s just not that complicated (assuming you have the right parts). And now you know what the right parts are.

Part Numbers

Crank 54121859594 


ECS Tuning sells a budget handle for $12.00 

Service Diagram (via RealOEM):


January 31, 2013 cosmetic, interior

I’ve wanted to swap in clear lenses since I got this car. The look of the old orange & red OEM signals which don’t really go with blue color scheme of my car, but the clear lenses are a subtle and austere remedy.

Removing the old ones can be done by hand, or if they are stubborn use a flat screwdriver to gently push sideways and pry the old sidemarker out. Also, for re-installation always install the light into the lens housing, then connect it to the wiring harness and snap into place. Otherwise any twisting of the housing may cause the bulb to work loose.

Lens Install


Clutch Pedal Stuck To Floor

In other news, this morning when leaving to wash the car my clutch pedal would not fully spring back up and I had to pull it back with my foot. Since then the clutch only engages at the very end of it’s throw and it feels like I don’t have much distance to work with when shifting. This only happened once but I suspect my master cylinder is failing. It’s a $70-170.00 part (depending on the retailer and brand name) but there’s some know-how required to replace the part and bleed the system of air.

This, combined with engine and drivability issues detract slightly from my enjoyment of the car but I’m doing my best to keep it on the road but I don’t think I’ll be driving it until I get this sorted out sometime this week or next weekend. I may have to take it to a shop if I don’t have time to deal with it.

BMW CCA GGC Cars & Coffee

Also today the wife and I went to the BMW CCA GGC “Cars & Coffee” meetup to see some friends and make some new ones. Lots of M cars there today and some interesting M1s with engine swaps!

Related Post:

Clear Side Markers & Turn Signals


Sidemarkers: BavAuto.com (Search for Part “E30/32/34 CLEAR”)
Turn Signal Lenses: AbramsMotorsport.com 


BMW e30: Clear Side Markers & Front Signals Install

Front Turn Signal Bulb (Clear): Sylvania 7528
Front Turn Signal Bulb (Amber): Sylvania 1157A
Sidemarker Signal Bulb (Amber): Sylvania 2827


The amber front turn signal bulb is lower voltage, but is keyed correctly for the BMW e30 turn signal socket. This may cause the light to burn out more often or run hotter but it works.

January 13, 2013 cosmetic


  • spent half my vacation sick
  • tried to talk about stuff other than cars
  • noticed that VWs are the Euro car of choice in Canada
  • drove a VW Passat. it was a mellow ride, didn’t like the way it sounded.
  • Petro Canada sells 94 octane!
  • e39 touring had a dead battery when we returned
  • now a pro at extracting battery from powerless e39 touring
  • e30 was filthy from 2 weeks of Caliornia rain
  • washed it today, needs another wash to get really clean

Side Marker Drainage Holes

The front sidemarkers on my car were crappy: one was always falling out a little, the other was collecting water. Replaced both, drilled a hole in the bottom of each so any moisture can drain.


January 1, 2013 cosmetic, status

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