All-aluminum radiators are a popular choice for race applications and cars with modified engines. My daily driver with stock m20 motor fits neither category but I’ve been diagnosing the common jumpy temp gauge and wanted to make sure my radiator is flowing freely and providing maximum cooling. Also, the super clean appearance of aluminum radiators appeals to my sense of aesthetics so I basically convinced myself to do this upgrade.

My criteria for the replacement radiator was improved cooling and OEM fitment. I set on the Mishimoto e30 / e36 radiator after recommendations from friends and finding only positive reviews in online BMW forums. Mishimoto offers a lifetime warranty which is comforting.

e30 Mishimoto radiator in box

However, my decision shouldn’t be taken as endorsement and I haven’t run this radiator long enough to provide a real product review. After I installed this my close friend and local e30 expert Eric Berger told me that he knows several people who have had these radiators fail. In some cases the failure resulted in motor damage: it’s “buyer beware” as always. For the record Eric recommends Behr.

Because of Eric’s emphatic warning I’m going to monitor this radiator very closely especially as it approaches the first year of service. I did some further internet searches and found few reports of failures with the Mishimoto products. Mostly I found complaints about fitment. The few cases I found of failure were related to running straight water (no coolant) for long periods of time and in some cases not even using distilled water. Since coolant lubricates the moving parts of the cooling system and iron in water reacts with aluminum I blame careless owners for those failures I read about. I’m not sure what the issues were with the other local guys who had failures.


Build Quality and Fitment

I found the quality of the Mishimoto radiator to be good and I would rate it a 9/10. It loses points for two reasons. Firstly, some of the fins were bent and a couple near the top were sheared off out of the box. Radiators are delicate but I’d expect it to be perfect on arrival. There’s a tool that can fix bent fins so I guess I’ll buy one.

Secondly I found fitment to be imperfect. One of the support posts was angled slightly outward. From post edge to post edge the radiator should be 26″ across but because of this defect my Mishimoto radiator was 26.15″ across. The solution was to cut down one of the rubber radiator mounts so that it would still seat to the radiator support. I don’t like this solution as it looks sloppy and failure due to a weakened mount is a concern.

Not necessarily a show stopper but there’s no fan shroud for a mechanical m20 fan that fits on the Mishimoto. I mean, you can throw one on but there’s no where to zip tie or clip it onto the rad. I’m still researching that.

mishimoto e30 radiator mounts wrong fitment

Above: This post for the radiator mounts is angled incorrectly which caused improper fitment.

mishimoto e30 radiator fitment adjusting mounts with knife

Above: Cutting the passenger side rubber radiator mount for fitment.

Installation Notes

  • Installation was easy. It took 30 minutes to remove the hood and old radiator and another 45 minutes to install and reconnect the new radiator including the time it took to solve the problem with the radiator mounts. From start to finish including bleeding it took me 3 hours. I ran into no problems because my hoses are all fresh and flexible. Older hoses may cause more problems.
  • Don’t forget to buy high temp teflon tape for your fan switch. The radiator ships with an aluminum delete plug for the switch port.
  • The Mishimoto drains directly from the bottom of the rad. Draining will splash coolant off the radiator support and make a big mess. Some kind of petcock with a 12mm x 1.5 would help but there’s not much room to fit it.

Mishimoto radiator installed in my late model 1989 BMW 325i e30
Mishimoto radiator installed in my late model 1989 BMW 325i e30

Above: Mishimoto radiator installed in my 1989 BMW e30.

October 5, 2014 mechanical, repairs

At my two most recent BMW CCA autocross events the typical comment from my instructors (i’m still a ‘novice’) has been “wow, you’re pretty smooth even though you have to shuffle steer.” It became clear that the stock 4-turn e30 steering rack was slowing me down and needed to be swapped out.

At the outset I thought this project would take a day, maybe two at the most. It actually took 3 weekends to complete because of missing parts and tools. I also wasted a lot of time researching various steps and confirming that I was doing the right thing. Hopefully my experience will help you with your own steering rack swap. I learned some valuable lessons about this kind of work:

  1. Test fit everything “on the ground” before the day of install. This includes checking bolt fitment in new parts and final assembly. Don’t assume all parts were shipped.
  2. Check all available photos and diagrams for parts and examples of how final install should look before the day of install.

I started my research by asking for some opinions which fell into two categories:

  1. The e36 z3 rack is too twitchy, go with a 95 e36 M3 rack with a lock to lock of 3.0 turns.
  2. You can handle it, go for the e36 z3 rack with a lock to lock of 2.7 turns.

e30 rack vs z3 rack

Above: Comparison of Racks. (Photo Source)

I heard so much praise for the z3 rack, like “best mod ever for an e30″, that I decided to pursue it. Next I started researching the method: most of my web searches turned up the same DIY (posted on R3vlimited) time and again so I decided to follow it. Going with the DIY seemed like the only option but was my first and most costly, time consuming mistake.

I want to put a very fine point on this: If you are planning to do an e30 steering rack to e36 m3 or e36 z3 steering rack swap you should buy a complete kit. There may be other retailers but the kit used by people I know is available from Zionsville Autosport. The pros to buying the complete kit is substantial savings over buying the component parts and the kit is complete requiring no retrofitting or fabrication to install unlike the DIY procedure. I wasted a lot of time blocked because of missing tools, fiddling with retrofits and installing things incorrectly. Save yourself the trouble and buy the kit.

But I didn’t know about the complete kits when I started so I set about ordering the parts I’d need. Web searching led me to The Rack Doctor who I ordered from because I felt most confident that I was getting the rack I wanted. On a scale of 1-5 I’d say my experience was a 3.5.


  • Rack was clean, painted
  • They called to confirm that I wanted e36 tie rod arms vs. e30 (there is a difference)
  • New copper crush washers were included but just for the rack, not the pump
  • Shipping was quick


  • Paint chipped horribly during install especially on some of the plastic hoses
  • Some important nuts and lock clamps for tie rods were not included which delayed install
  • High core charge not refundable except for identical core return

The DIY I referenced listed out the following parts:


2x 7/16 Bolt 2 Inches Long
2x Bolt M10x50 26111226737
2x Self Locking Nuts 07129964672
4x Copper Seals 14×20 32411093596
4x Copper Seals 16×22 32411093597
4x Self Locking Nuts 07129922716
1x Power Steering Reservoir 32411097164
1x High Pres. PS Hose 32411141953
1x Spacer 72118119268
2x Spacer 72111847480
2x Nut 721119779250
2x LP PS Return Hoses
1x Bottle of ATF

Some of these parts are NLA or the author just didn’t list part numbers. I have crossed out the list entirely because I don’t think you should reference it. Here’s my recommended parts list:

My Updated Parts List:

4x Copper Seals 14×20 32411093596
4x Copper Seals 16×22 32411093597
1x Power Steering Reservoir 32411097164
1x High Pres. PS Hose 32411141953
1x LP PS Return Hose 32411135936
1x LP PS Return Hose 32411133401
1x e30 to e36 Steering Knuckle Kit (either RPKIT or the kit from here)
1x *e36 Left Ball Joint 32111139313
1x *e36 Right Ball Joint 32111139314
2x *Clamp Ring 32111136179
2x *Nuts 32111136494
1x Bottle ATF Fluid

*Necessary only if you get the e36 ball joints and these parts are not included. e30 tie rods require a different locking nut and may be reused from your old rack. Probably.

BMW e36 tie rod clamp ring parts
BMW e36 tie rod clamp ring parts

Above: Clamp rings and chunky nuts required but not mentioned in the DIY.


Above: The tiny nut shipped with the e36 z3 rack that is not suitable for this swap.

Additional Tools:

Two 15mm wrenches (for the knuckle)
8mm and 6mm extended hex bits (for installing the knuckle kit around the parts of the knuckle – you’ll see!)
Tie Rod Puller
Bottle Jack (for flattening the rack tabs)
C-Clamps (for depressing brake cylinders)

A note about tie rod pullers: There are two styles. The most common style you’ll find at your local auto supply store features a single U shaped clamp with a bolt through the center. This bolt has a pointed tip that seats in the top of the ball joint bolt. The bolt must have a divot in the top for this tip to seat in otherwise it will not work, and it should be noted that the e36 arms do NOT have this divot. Also note that in order to use the U shaped puller you will need to take off the rotors and loosen the dust shield. It’s really loud when the bolt finally breaks loose but a little less violent than banging on it with a hammer or a pickle fork. The other kind of puller looks like a metal clothes pin and a bolt is used to close the jaws of the pin, again pushing the ball joint bolt out. This tool works by pressing down on the ball joint bolt with a flat surface and therefore works on bolts that do NOT have a divot in the top. Like e36 tie rods and ball joints. So if you have the choice get the clothes pin kind of tool since it’s more versatile.

BMW e30 e36 Two kinds of tie rod pullers

Above: Two different styles of tie rod end pullers.

BMW e30 e36 Tie rod puller in use how to

Above: The clothes pin style of tie rod puller in use.

Notes and Addendum to the DIY:

  1. Disconnecting the ball joints and tie rods was impossible for me without using a puller. A hammer and block of wood only resulted in destroying the wood. Tie rod removal also required the removal of the brake calipers and loosening the dust plate to make enough room for the puller.
  2. BMW e30 tie rod end arm puller removal

    Above: The U style puller. Notice how much room it requires next to the dust shield.
  3. I used zip ties and plastic bags to keep the hoses from dripping after disconnecting them. Keep your work space clean.
  4. Take photos of where the old hoses run so you can run the new hoses along the same pathway.
  5. Removing (and installing) hoses on the rack need to be done in order: there is not room to remove the upper banjo bolt while the lower bolt is in place.
  6. The DIY called for bending the rack tabs on the center cross member to make room to drop the rack. In retrospect lifting the motor or bending these tabs the very smallest amount required would be advisable. I spent 2 hours working the tabs back into place with a bottle jack and some folks posit that bending the tabs weakens them.
  7. Plan to soak the knuckle to rack spline in PB blaster over night. The knuckle to steering column spline slipped right off but I could not remove the knuckle from the steering rack and ended up sourcing a donor knuckle while waiting for the PB blaster to work. I finally got the knuckle off by standing on the old rack and pulling. I can deadlift 300 lb. so that says something about how seized up the splines may be. Also note that the bolt on the rack side of the knuckle must be completely removed as it passes through a slot in the spine that holds it on. You cannot remove the knuckle with the bolt merely loosened.
  8. If modifying your current knuckle i.e. not using a pre-fabricated knuckle then you need to remember that the kit or shortened spacer is used to make the knuckle shorter NOT longer. You will need to enlarge two of the holes on the knuckle to fit the bolts through. A 23/32 drill bit was the right size for me but you should use a bit gauge to measure your bolts.
  9. I needed to tap the knuckle onto the rack spline using a hammer. Actually a friend with more experience did it for me. This should not be necessary but if you simply can’t work the knuckle on by hand then be very sure that the splines are not binding and are lined up properly before gently tapping it onto the spline. Go slow, you’re not driving a nail.
  10. The rack and knuckle need to connect to the steering spline when both are centered (this is mentioned in the DIY). I used a protractor and made a measuring tool to count the number of degrees in a complete lock to lock rotation, dividing the total by 2 and then finding that middle point in the racks rotation. In my case middle was 510 degrees. This is very accurate and does not require the removal of the boots, etc. to measure the tie rod ends. I marked this middle point on the rack and spline using a white paint marker for reference during install but marked it on the side I couldn’t see: make your marks so they are visible when the spline is on your left.
  11. Using rubber bicycle inner tube to protect splines
    e30 rack swap how to center rack
    e30 rack swap how to center rack

    Above: Finding the center of the rack.
  12. Even after finding center I still had to disconnect the rack and knuckle and move it over a single spline tooth. If you put a peice of tape at dead center on your wheel and turn it all the way to the left and right you should see that the terminal position of each is the mirror image of the other. My first attempt found it to be 2″ off (about the amount of a single spline tooth).
  13. The DIY reads “if there is binding use your Dremel to grind the knuckle joint.” You should assume that the knuckle will bind and grind it down on your bench where you have maximum control NOT when it’s installed in the car like the DIY shows. I recommend using a cutting bit not a grinding bit as the amount of metal you need to remove is significant. I removed metal from the U but in hindsight grinding down the edges of the fork may have been tidier and resulted in less cutting.
  14. Dremel cutter grinder bit for shaving down steering knuckle in e30 z3 swap
    Dremel cutter grinder bit for shaving down steering knuckle in e30 z3 swap

    Above: The correct Dremel cutter bit used for shaving down the knuckle to prevent binding.
  15. The DIY calls for tapping the cross member tabs into place with a hammer. This is impossible as the tabs will bounce and absorb all the force of the hammer. Using vice grips mangled the tabs. I recommend using a bottle jack and wood blocks under the tabs to bend them into place but be careful not to lift the car by accident. Putting the rack and spacer on the tab while bending the tabs up will help make sure you don’t bend the tabs too far the other way.
  16. bmw e30 z3 rack install bending cross member tabs back into place

  17. If you use the hoses called for in the DIY you can bend the new high pressure hose into place using your hands, or a little heat and your gloved hands. Using a vice or bender should not be required. Only the pump side should require bending. Study my photos and try to match what I’ve done.
  18. BMW e30 steering rack swap high pressure hose bends
    BMW e30 steering rack swap high pressure hose bends
    BMW e30 steering rack swap high pressure hose bends

  19. The new hoses are a tight fit. The new high pressure hose will need to go over the motor mount arm. Just make sure there is a finger’s width between each hose as you tighten it down because rubbing hoses will eventually spring a leak. Two sets of hands can be helpful here.
  20. During bleeding of the steering rack do not press the brakes because you may over extend the brake piston. If you do this by accident you may be able to use a c-clamp to compress the piston back down. Otherwise a bleed and flush will be required.

BMW e30 e36 z3 rack swap tie rod arm bolt and clamp
1989 BMW e30 sedan blue on flat bed recovery vehicle

Above: Towing my e30 to Bavarian Motorsport in Milpitas, CA for an alignment.

1989 BMW e30 alignment at Bavarian Motorsport

Above: My 1989 BMW e30 on the alignment rack at Bavarian Motorsport in Milpitas.

August 29, 2014 mechanical, repairs

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


Yesterday my e30 started generating a persistant CEL (Check Engine Light) error 1221 which indicates the o2 sensor has failed or is sensing values so far out of spec it can’t be interpretted. I suspect that driving around with a nagging misfire for almost a month fouled the sensor. The sensor is only a couple months old, which is a shame. Thankfully I kept my old sensor which I’ll use until it fails or I finally swap in a s52 engine.

February 12, 2013 mechanical, repairs

My little blue buzz bomb has been driving like it’s up to it’s bumper in peanut butter. This has been going on for 2 or 3 weeks, but generally driveability has been declining for the last 2 months. Initially I thought it was a fuel problem which wasn’t totally out there but my mechanic drove it and was 90% sure of an ignition problem on the primary side.



  • initially idles rough, runs strong once the temp. gauge starts to move (“normal” for this car)
  • runs great for 5, 10 minutes
  • at some point driving or idling CEL (1221 o2 sensor) comes on
  • at the same time sounds and acts like a cylinder is dropping
  • loss of power especially at low RPM, poor fuel economy
  • let it sit for 20-30 minutes
  • it will initially start up like the cylinder is missing with CEL still lit
  • after 20 seconds the CEL clears and it drives fine for another 5, 10 minutes
  • non-conductive spark tester thing seems to indicate it’s cylinder 5 that is misfiring

The happy ending to this is that it’s finally fixed! But I’m going to relate the story in 3 sections: what I’ve learned, what fixed the problem, and then I’ll talk about everything else I tried to fix the problem.

4 Easy Lessons

  1. Start At The Ends: To experienced trouble shooters this is probably so obvious that it’s stupid. But the “ends” of a system – where stuff is input and where stuff is output – are the best places to look for solutions. If you turn on your tap and no water comes out you wiggle the faucet, check for hot and cold and then you check to see if the rest of the house has water, right? The problem is likely at one of those two places. More complicated systems tend to be the same: check the ends, then work your way backwards from the output end.
  2. Start With The Easy Fixes: If something just needs to be cleaned, adjusted or can be eliminated with a visual or low-tech inspection then start there. Because isn’t it awesome when something is an easy fix?
  3. Diagnostics Over Parts: It’s better to run tests than throw parts at a problem. It’s cheaper and doesn’t introduce new variables. You’ll always have people telling you to replace this or that part but that’s wasteful. Save you money and energy for the really hard problems.
  4. Cleaning Is Maintenance: Cleaning your car is a chance to inspect stuff. Typically I stay out of my car’s underside because I don’t get it onto jack stands very often but I will do better in that area now.

Problem Solved: Clean the Crank Position Sensor (CPS)


Above: CPS location and closeup.

So I’ve heard of the CPS before. Heard people talk about:

  • the wires being frayed
  • adjusting it (early model e30s only, so I’ve learned)
  • it can test o.k. and still not work
  • if you have spark and fuel it must be working (confused yet?)

Generally I was confused and unsure of what to do with it, though I knew it was in scope for the problem I was having. Here’s the layman’s explanation of what the CPS does (source):

Any one of the things I’ve replaced could cause the symptoms I’ve noted, but replacing parts did nothing because the parts weren’t actually failing or bad. Other things that were blamed by people I asked:

  • CPS
  • DME (it’s a computer, almost untestable without the right equipment)
  • oxygen sensor
  • cap and rotor (even though I just replaced it)
  • HT wires

Most people want to throw parts at this kind of problem, so I’m glad it didn’t come to that for me. That’s the end of the story, so here’s some photos taken during the various fixes:

  1. Replaced the plugs because I was checking them anyways. This was #6 which looks bad but would still work in that condition.
  2. Checked the plug wire set and found that the #5 wire had a cut in it.
  3. Off to the Pick n Pull to find another wire set. This one was not perfect but it was a match and the only one available. e30s are not appearing at the dismantlers very often, right now.
  4. Dirty but nothing I can’t clean up. Discovered that some of the wires were not in good condition but had what I needed. The entire harness was only $10.
  5. Quick solution to see if the new wire makes a difference. It did not.
  6. New cap & rotor and cleaned up that harness. The wire cover is now black!
  7. Tested the coil. Seems out of spec.
  8. Borrowed a coil from a friend. Of course it made no difference.

Image Gallery

February 8, 2013 mechanical, repairs

If you own an e30 with an old fuel pump then I recommend replacing it even if it isn’t yet making death-rattle noises: the difference will be so obvious you’ll swear your e30 has more horsepower. This is a 20 minute job.

I got my pump and sender from the Pick n’ Pull for $70. Normally I would not have installed used parts in this application but I found a remarkable specimen and scooped it. If you have the means I suggest buying new for reliability and because there are so many after-market pumps available that are excellent and cheap especially if you have an engine with a higher than average LPH (litres per hour) requirement.


In my photo above you can see the new pump and sender have nice white plastic bits while my old parts are all brown. This isn’t aging it indicates a material update seen in newer fuel pumps. Expect to spend $250-280 for a new pump and sender, less if you retrofit a non-OEM pump.


The before (top) and after (bottom).

This job is dead simple and well documented. This thread on r3vlimited has some insights into noises and rusty fuel tanks. I won’t duplicate the step by step but I will share my notes on the procedure:

  • was happy to find foam seal still in place, though incorrectly installed
  • was not happy to find 1/8″ of dust covering everything
  • one of the nuts that hold the sender to the pump was missing: someone was in here before me apparently
  • cleaned up the dust as best i could, next time i’ll bring a brush and vacuum
  • stuffed paper towels all around the hoses
  • disconnected plugs and fuel hose (came off easily, no need to mangle the hose)
  • tried to block the hose with a sharpie but it was too big – a bic pen would work better
  • removed sender and put it in a bucket
  • could have used a hammer and screwdriver but just used muscle to spin & remove pump
  • pump locks onto the gas tank simular to the child-proof cap on medicine bottle
  • discovered the filter sock had fallen off and was in the tank
  • car has probably been guzzling all manner of dirt and gunk for years
  • based on that suspect fuel filter (1 year old) is gunked up and will need to be replaced next
  • went to home depot and bought a little claw to get the filter sock out of the tank
  • proceeded with new (to me) parts, clean up, etc.
  • car ran super rough initially probably due to air in the fuel line
  • eventually cleared up: car feels stronger, smoother acceleration
  • fuel guage still reading incorrect, may need to replace 2nd fuel level sender
  • filled up tank to try to dislodge sender float, will see how guage changes as i drive it
  • whole car reeks of gas, as do i.

Update (Monday 2012-01-28):

My e30 is messed up, stuttering and lacking power. Though it ran strong for an afternoon my “exceptional specimen” didn’t have much life left. Here’s how I’ve determined that the pump fuel supply is the problem: When the car stutters during acceleration, check the tachometer and fuel economy guages. If the RPMs drop that usually indicates a lack of spark. If the fuel economy drops that indicates the engine is starving for fuel.


My car is doing the latter, puttering at between 5 and 0 MPG in every gear and whenever the throttle is open. Tomorrow I’ll get up early and try hopefully swap in my old pump.

Update (Tuesday 2012-01-29):

The old pump improved drivability but I can tell it’s a short term fix because my old pump is making noise sometimes and the MPG frequently and nearly bottoms out just driving normally. This could be a combination of factors (fuel pump, fuel pressure regulator, injectors) but I suspect the pump.

This time it only took me 15 minutes to swap pumps but I’ll be doing it again soon so maybe I can do it even faster next time. There are several aftermarket pumps available but I decided on an OEM pump from TurnerMotorsport (they have the best price).

The bodger retrofit is to buy a pump and kit and rig it into the pump armature. The most common pump for that applicaiton is the Walbro 255 GSS-340 (DIY Retrofit Instructions). Cars with higher displacement engines or turbos sometimes put in a pump with greater LPH (litres per hour) such as the  Deatschwerks 300 LPH but that’s not necessary for a stock engine, even an s52 let alone an m20.

I’m a sucker for OEM.

Update (Sunday 2012-02-03):

I’m still convinced I have a fuel issue but my mechanic drove the car and says it has the tell-tale signs of a spark issue. I replaced the plugs in the 4 troublesome cylinders (which were actually o.k), replaced a cracked HT wire and swapped in the new distributor cap and rotor from my trunk kit for good measure: problem persists. If my mechanic is correct then the next item to inspect is the ignition coil.

Update (Tueday 2012-02-05):

My new OEM fuel pump arrived last night and I installed it in the dark. Works great and I can definitely feel that the car has new energy. Afterwards I drove it around the block with the pump exposed and the seat cushion off and it was crazy how loud the pump is. However my surging and powerloss issues prevail and I am going to replace the ignition coil to try to remedy that. As I’ve read, the coil can fail completely but it can also fail slowly causing exactly the symptoms I’m experiencing.

One last thing, It’s worth noting that every time I’ve done this there has been very little fuel in the hose coming off the pump, but this time there was much, much more fuel. It’s a good idea to remove the fuel sender before disconnecting the hose so you have somewhere to drain all that fuel.

How to:

Fuel Pump Replacement 

Part Numbers:

Suction Device with Pre-Supply Pump (255 LPH) 16141179415
O-Ring 16111744369
Sending Unit Assembly 16141152266 

Service Diagram (via RealOEM)

BMW e30: Fuel Pump Replacement

January 26, 2013 mechanical, repairs


A – Santa Clara to Pacifica via Hwy 280

This drive happened last Saturday. I missed the Half Moon Bay exit so we took 280 north and doubled back a little to get to Pacifica. We went to Nick’s on Rockaway Beach for lunch. The parking lot is right on the ocean and if you don’t park carefully your car will catch a lot of ocean spray! The food at Nick’s was o.k. – I had the fried oysters. Not sure it was 4 stars, but it was good enough. If we went back to Pacifica for lunch we’d probably go back.

If you want a dramatic place to take photos of your car, this is the place to go: if you get there early you could get a good spot right next to the water.

As we continued down Hwy 1 I was worried that I was holding up the cars behind me but we quickly caught up to other traffic on the road and the courteous concern left my mind. As long as I’m driving safely and not being the slowest car on the road then I’m happy.


B – San Gregorio State Beach

This was not exactly a planned rest stop but it wouldn’t be a real trip in the e30 without a little drama. After we left Pacifica the car started misfiring. We pulled over and after a quick check in with fellow e30 drivers via Facebook I decided to pull my #5 spark plug (known to burn oil in my car) without waiting for the engine to cool completely. I was careful with my breaker bar not to put undue stress on the plugs and the engine was not red hot. I also could have burned my fingers so I was being extra careful.


The plug wasn’t too bad but I swapped it with a spare anyways. However I found the #1 HT wire gave a little “click” when I pushed on it at the distributor cap. My mechanic buddy doesn’t think that would cause a misfire (as we discussed the last time I had a misfire) but after I did that the car ran fine.


We hung out on the beach for an hour before heading home via La Honda, which is one of the area’s really good roads for driving. This time there were no slow pokes so I had a relaxing drive over the mountain and home.


December 4, 2012 driver's log, repairs

I took the car to Bavarian Motorsport and had a second smoke test. Found the throttle body to ICV hose leaked (at both ends and the elbow), and the brake booster vacuum elbows also leaked. All of these elbows are just pressure fit. Here’s what I did:

  • removed the air box, AFM boot and ICV
  • installed the TB to intake manifold gasket, which was missing before
  • sealed the brake booster elbows with black Permatex RTV gasket maker
  • fitted hose clamps to the ICV tube
  • sealed the ICV elbow with black Permatex RTV gasket maker
  • put everything back together and let it cure for 24 hours


I hate the way the hose clamps look but they’re necessary. So this worked great yesterday, but last night the car bogged after sitting for 2 hours. Now I wonder if the RTV sealant isn’t up to the heat of the operating engine.


Seems I forgot to tighten the hose clamps on the intake boot. Running better now!

November 24, 2012 repairs

Picked up a very reasonably priced and brand new o2 sensor. Took 5 minutes to install:

  1. locate the o2 sensor on the passenger side of the engine bay where it is screwed into the exhaust manifold
  2. spray it with some PB blaster and wait over night
  3. disconnect the o2 sensor from it’s harness
  4. because the o2 sensor is very close to the chasis you will not be able to use an o2 sensor wrench, instead use vise grips (push towards the firewall to loosen)
  5. remove the old o2 sensor
  6. manually thread the new sensor being careful not to get anti-seize compound on the tip
  7. you may have to flip the wiring harness around to keep it from getting twisted. tighten with the vise grips, turn towards radiator to tighten

The most important thing I learned was that all the commonly available o2 sensor wrenches will not work on the e30, but vise grips work perfectly. So I have 3 tools to return to Pepboys. I didn’t have access to the special BMW wrench but it’s hardly necessary.

This seems to have made no difference to how my car runs. Even though the old sensor was entirely encrusted in carbon and crud it was working fine or had no bearing on the car’s stalling, bogging and CEL.


Above: The new o2 sensor fitted to the exhaust manifold.

Part Numbers:

Oxygen Sensor, 325i/is/iC/iX (9/87-91) 11-78-1-734-393-M14

November 18, 2012 repairs

I don’t know how it got here, perhaps it hitched a ride from it’s home country of Deutschland to the new world or maybe it found the car here in the USA but it seems every e30 has a little gremlin that makes mischeif.

  • car was unlocking itself last weekend (info here), then suddenly issue goes away
  • replaced my AFM a couple weeks ago, car didn’t really like the new AFM that much and had low RPMs on cold starts
  • car developed a misfire which I fixed by replacing the plugs
  • for the last week the car has been bogging and stalling once on cold starts, generally have low power until it warmed up
  • suspect another vacuum leak, thinking car needs another smoke test, poked around the engine but found no cause
  • today problem suddenly goes away and car seems to run great
  • Links:

    e30 Central Locking FAQ (link)

November 10, 2012 repairs, status

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