e34 Touring

[straight6pwr]

had my drivers front brake caliper sieze up on me last friday. i had a random excessive steering wheel shake that started a month ago or so, so this explains it. 

replaced the caliper and rotor and beld the brakes

crusty!

mmm shiney
\

those guide pins LOL. the brake caliper piston wasn't great, either. 

[straight6pwr]

more borked stuff.

on that super artic freezing day of -36deg my cluster decided it had enough of f*ing wisconsin weather and stopped working. can't blame it. the entire cluster was dead except the speedo, the tach bouncing like caffeinated child, and the message "Code?" on the display. i've dealt with guessing how much gas was left in the tank since then and hoping the car didnt overheat. 

the internet suggests that either one of more of the capacitors has died, or, the cluster's Coding plug has malfunctioned. i decided to fix the capacitors and also buy a used Coding plug to cover both bases. both fixes cost about $25 combined.  I have yet to investigate if BMW is willing to replace the Coding plug based on my VIN or if they will require me to buy a whole new cluster. 

to remove the e34 cluster simply remove your steering wheel (process can vary if you have an airbag or not), remove the two screws in the top plastic bracket of the cluster, then slide the cluster out and unplug the connectors. with my non-airbag wheel, i can have the cluster out in 2 min. 

then, to split the cluster open, flip it over and locate the two screws on the top and remove. you can't see them here due to the perspective, but one is above 'VDO' and the other is mirrored on the other side. also, twist the two black twist tabs on the bottom 90 deg. then, the back part should hinge down and you can pull the two halves apart. 

on the back half you'll find the PCB. on the late e34 clusters (blue back) the board is held in by 10 plastic tabs that were expanded to pressure fit the board. you have to carefully drill out the tabs to remove the board. 

here you can see two of the tabs which were drilled out. 

different boards have different capacitors, but my board had 5 radial capacitors. shown below are three bluish gray capacitors on one end. 

on the other end of the board are two black capacitors. 

for my particular board the capacitor specs were:
(2) 22uF 50v (the ones on the board are listed as 40v, but that part is not readily available and 50v works fine)

(1)4.7uF 63v

(1)220uF 16v

(1)1000uF 16v

since I am a noobcake at this, I order (1) extra of everything in case I botch something:

here i've replaced one of the 22uf 50v capacitors with the new unit (but have not clipped the extra lead length yet). use your soldering iron and desoldering pump to remove the old capacitor, then simply solder in the new one.  the old and new capacitors are marked with - or + signs for the leads, be sure to keep track of that - they are not bi-directional. 

all three of the blue/gray capacitors replaced:

the old capacitors:

bonus nacho picture of me inspecting the whole board for other issues:

onto the coding plug!  on the late model clusters (blue back) there is a small blue chip that plugs into the back of the board which is the Coding plug or Coding chip. it supposedly contains information such as model, vin, gas tank size, speed sensor/rear diff ratio for speed calculations, and mileage. for the moment, the closest chip i could find for sale was from a 94 540 with 182,000miles. My car is a 530iT with 165k miles.  

To swap the chips, you have to pry up the blue cage that surrounds it on the back of the cluster (you will break it off, its designed that way) then you can just pull the old one out and plug in the new one. The picture shows the cage already removed. Refer to my 2nd photo above to see the cage. 

I'm not sure how the difference in gas tank size will pan out on the sensor, but so far everything else works perfectly.

RPMs and speed are not perfect, but are within  'statistical error'. 3k rpms = 67mph with a 1:1 trans, 3.23 diff, 25" tires. Mathmatically it should be 69mph.

well, its a good thing i had my temperature gauge fixed when I did, because today my car decided to crap its pants. 

Dejavu, anyone?

i was alerted to the issue when traveling down the highway and noticing quite the ploom of smoke following me. temperature guage was still normal, so it happened in a hurry and I pulled over.

turns out the outlet neck of the auxiliary water pump just up and sheered in half....

since I've been in a similar situation with the e30, i knew what i had to do. my wonderful gf came from home to take me to the auto parts store, I grabbed a coolant hose coupler and just bypassed the whole nonsense of aux water pump and heater valve and connected the block outlet and inlet together to get me home.

the stock aux water pump is BMW only and $180 (forget it!) but i think i found a universal bosch pump that will work in its place.  the heater valve is only a $50 part, so I'll replace that at the same time since its all out. other e34 owners on the internet suggest you can bypass the pump and all will be well, but the coolant system on the v8s is already so damn fragile i'd rather fix it than risk it. 

heater valve and aux water pump: 

oh, and I ran into Joe when i was waiting for the car to cool and bleed off the excess air down by the lake, which was nice. his wagon is mmmmm

[Boris3]

And I thought the plastic pipe on the m42 block was a stupid design flaw. The whole e34 plastic aux pump thing looks like a failure point just waiting to happen. Glad you didn't trash the engine.

[straight6pwr]

i suppose the marketing wankateers at BMW thought the owners deserved INSTANT hot air in the cabin and this was their extra-complicated way of providing that.

[RobZR]

You ain't seen nothing yet.

Take the 4 screws off the pump head and see the marvel of German engineering. A magnetic coupled impeller driven through a clear polycarbonate cup. 

Who had the bright idea to think this would last?

I had one wear through the clear plastic cup and fail in a steaming pile like yours. Bypassed by connecting the broken hose to the heater valve input and haven't noticed any difference.

[straight6pwr]

RobZR said:

You ain't seen nothing yet.

Take the 4 screws off the pump head and see the marvel of German engineering. A magnetic coupled impeller driven through a clear polycarbonate cup. 

Who had the bright idea to think this would last?

I had one wear through the clear plastic cup and fail in a steaming pile like yours. Bypassed by connecting the broken hose to the heater valve input and haven't noticed any difference. 

i've never actually heard of a mag-drive pump before, pretty cool idea. but, yeah, research suggests that it adds more complexity, size and cost for a slight uptick in leak resistance of the seals, which seems unnecessary here.

[jc43089]

I was under the impression that the aux pump was to provide hot coolant to the heater core after a shutdown so you can run the heat for a while after shutting the car off.  I don't think it has any function for the cooling of the engine.  I removed one on an e32 because it was leaking.

[m42b32]

Maybe not ideal circumstances to run into each other, but it was fun catching up for a second! I'm glad you made it home without too much of a struggle

[straight6pwr]

jc43089 said:

I was under the impression that the aux pump was to provide hot coolant to the heater core after a shutdown so you can run the heat for a while after shutting the car off.  I don't think it has any function for the cooling of the engine.  I removed one on an e32 because it was leaking.

i was thinking it was to get the hot coolant circulated through the heater core as fast as possible, but your scenario makes sense. I'll have to listen to the pump to see if it runs with the car off and the heat on. with how much heat these engines make, you could probably crank warm air through the vents for hours.

[straight6pwr]

welp, I finished some projects finally.

i used a 3rd cluster to steal the display LCD and finally got the cluster 100% working again

glued one of the door panels back together

got the ebrake unseized

new console surround installed

aux pump and heater valve rebuilt and installed in the car. new coolant added.

Steering components 100% replaced. new idler arm, new tie rods, new center drag link. 55mph shimmy is finally gone again. 

the remaining three brake calipers (replaced one in spring) all seems to be at different levels of 'stuck', so I just replaced everything.

bottom of the ocean or winter wisconsin car? I think the partial seizing led to extra heat which accelerated the rust on these. 

before:

new parts:

after:

then, I took some pictures to be used for selling the car:

then, before I could blink, the car was sold. gonna miss this one, we had a lot of great adventures.

/thread

[m42b32]

One of my favorite wagons. Congrats on the sale, whats next??

[B C]

You’ve done well with this E34 and seem to have gotten some great use out of it. How long was it listed before it sold?

[straight6pwr]

Some other wagon will be next if things go as planned. 

I didn't even have to list the car, actually. Responded to a wanted ad.

[YoungCR]

Congrats on the sale! Gonna miss this car too.

[Jdesign]

Congrats. Cant wait to see whats next!