Help Support Bigcoupe.com

1984 633CSi Rises again!

Document your Sixer project here.

Moderators: ron, bfons, GRNSHRK

Jlc
Bigcoupe 100 Post club
Posts: 276
Joined: Sun Sep 27, 2020 5:27 pm
Location: Atl

Re: 1984 633CSi Rises again!

Post by Jlc » Mon Mar 28, 2022 1:54 pm

KINGJOHN808 wrote:
Sun Mar 27, 2022 5:56 am
Hope to have it back on the road by next year. Turned the plates in a few years back so not get get charged back taxes. Registration here in Hawaii is a rip off. Car is almost 40 years old and the registration is going to cost $460.00
Ouch. Mine costs more for the "Mail Fee" of $1 (even if done on line) and vanity tag of $20 than the actual tax.
85 635CSi Bronzit

songzunhuang
Platinum Member
Platinum Member
Posts: 1039
Joined: Fri Aug 14, 2015 10:04 am
Location: Silicon Valley, CA
Contact:

Re: 1984 633CSi Rises again!

Post by songzunhuang » Thu Apr 07, 2022 1:51 am

KINGJOHN808 wrote:
Sun Mar 27, 2022 5:56 am

My later issue is the OBC. I changed the fuse and soldered on a big tail with fuse holder so if I have another issue with the fuse blowing, it’s way easier just to pop it out and change it. It seems to be functioning, however the light (buttons do not light up). Checked the bulb and it appears fine so not sure why it’s not on. Even when I turn the dash lights on and off, only the display works, but the buttons do not.

Aloha’z.
The OBC computer has a bulb at the top center and a bunch of optic fibers that carry the light to the keys on the keypad. I took mine apart once trying to diagnose the issue. My issues turned out to be the actual computer and not the head unit.

In any case, here are aa few pics of the innards of the OBC.
OBC.png
Disassembling OBC
OBC.png (1.08 MiB) Viewed 352 times
And a clear picture of the bulb mount and how the fibers carry the light.
oBc Open.png
Optic fibers carrying light
oBc Open.png (1.23 MiB) Viewed 352 times
I've actually replaced the head unit because I had a red LED segment burn out. It was easier to get a used on on eBay than to attempt to fix one of the LED digits. Now I have a spare if I ever need it.

back to your issue. If you can verify that the bulb is getting power and lighting up, it should light up the keypad.
-----
Song Huang
1984 633CSi
Last 7 of VIN: 6997383

KINGJOHN808
Bigcoupe 100 Post club
Posts: 100
Joined: Sat Feb 16, 2019 2:27 am
Location: Ewa Kai

Re: 1984 633CSi Rises again!

Post by KINGJOHN808 » Thu Apr 07, 2022 2:09 am

songzunhuang wrote:
Thu Apr 07, 2022 1:51 am
KINGJOHN808 wrote:
Sun Mar 27, 2022 5:56 am

My later issue is the OBC. I changed the fuse and soldered on a big tail with fuse holder so if I have another issue with the fuse blowing, it’s way easier just to pop it out and change it. It seems to be functioning, however the light (buttons do not light up). Checked the bulb and it appears fine so not sure why it’s not on. Even when I turn the dash lights on and off, only the display works, but the buttons do not.

Aloha’z.
The OBC computer has a bulb at the top center and a bunch of optic fibers that carry the light to the keys on the keypad. I took mine apart once trying to diagnose the issue. My issues turned out to be the actual computer and not the head unit.

In any case, here are aa few pics of the innards of the OBC.
OBC.png

And a clear picture of the bulb mount and how the fibers carry the light.
oBc Open.png

I've actually replaced the head unit because I had a red LED segment burn out. It was easier to get a used on on eBay than to attempt to fix one of the LED digits. Now I have a spare if I ever need it.

back to your issue. If you can verify that the bulb is getting power and lighting up, it should light up the keypad.
Aloha! Yep, checked everything. 12vdc running across the bridge, changed and checked the bulbs. Even changed out the OBC computer and OBC display. Same issue, no change. I’m kinda over it now because I don’t really need that function, was just cool to have everything working how I remembered from back in the 80’s.

Have a work around planned for getting light into that area. Not original, but won’t be able to tell the difference once everything is put back together.

I’ve come to realize that these cars are a lot like my VW’s, there is a “work around” to everything. May not be original, but it works. :D

Aloha’z
Ewa Kai, Hawai’i
1984 633CSi
1983 633CSi (wreckers)

“Aloha and have a great day!”

songzunhuang
Platinum Member
Platinum Member
Posts: 1039
Joined: Fri Aug 14, 2015 10:04 am
Location: Silicon Valley, CA
Contact:

Upper Control Arms, Battery, Differential Oil

Post by songzunhuang » Tue Apr 12, 2022 6:45 am

Catching up on the work I've done on the car over the past 2 weekends.

Upper Control Arms:
I received the part from 1A Auto. Those folks make great videos online and also offer a limited lifetime warranty. Recall, they were also the only place I could locate a complete set of upper control arms, sometimes called thrust arms. They came very well packaged and I also noticed the parts were marked "Made in Turkey", which was the same as the Meyle lower arms delivered a few weeks earlier - interesting. Also a few other observations, these arms have a slightly more dramatic bend than the original BMW part. They feel hefty and the rubber bushing is very different. In the picture below you can see that the bushing has more and thicker rubber. The BMW part had a plastic insert. When I removed the insert, there was a much more pronounced gap in the bushing. Also note that the red poly boot on the BMW arm was something that I installed only a week ago. That was a waste of money. Overall the 1A Auto replacement looks to be of very good quality. The casting and machine work and finish look very good. Time will tell.
Control arm compare.png
1A Auto vs BMW part
Control arm compare.png (761.42 KiB) Viewed 312 times
On the passenger side there's a heat shield protecting the bushing side of the control arm. You'll definitely need to remove it to pull the bolt all the way out. Also, in this picture, the shield has not been cleaned up. It was all black from oil and grime, but it's all shiny silver now!
Heat Shield.png
Need to remove to access
Heat Shield.png (750.99 KiB) Viewed 312 times
After installation, final tightening on the bushing side is done with the car loaded. I put everything back together, the wheels back on and then drove the car up on ramps before crawling under and tightening the bolts. One difficulty was that I couldn't get my torque wrench in there to tighten to the 96 ft/lbs specified. There just wasn't enough clearance. I just had to use my regular socket wrench and tighten with all the strength I could muster using the normal handle. I'll check all the bolts again next weekend.

New Battery:
The last 2 times I started the car, I noticed that it turned over kind of slowly. I once that to charge the battery a little before it would crank. I realized that I have had the same battery since 2015 with over 50,000 miles of driving. I figured it was time to get a new battery as I don't want to get stranded. I got the exact same brand (from O-Reilly) as it has served me well. It was $212. After I installed it, it cranked very energetically and I noticed that my battery charging light now goes off almost immediately after the car starts. I used to have to rev it a little to make it go out.
New Battery.png
Lasted almost 7 years
New Battery.png (720.09 KiB) Viewed 312 times
Final Drive or Differential Oil:
Finally, something had been bugging me. I've never changed the final drive oil on the car. For all I knew, it was the original oil in there. Well, it just took a 10mm allen wrench and a psuedo breaker bar (those plugs were tight!) to remove the plugs in order to change the fluid. What drained out wasn't as nasty as I expected. Remove both plugs to drain and then replace the bottom plug. Fill from top hole until it starts to come out of the top hole, then replace the top plug. In any case, I refilled with 80W/90 GL5 gear oil. I should be good for a long, long time.
Diff oil.png
Wasn't too bad.
Diff oil.png (1.47 MiB) Viewed 312 times
So how is everything? Well, it's been over 150 miles of driving and everything feels tight. I'll need to get it aligned as I have a slight pull to the right, but the shakes are gone. I think I may have licked the vibration issue. But wait! Now I hear a squeaking sound from the passenger front suspension as I turn the wheel. I think my spring bushing may be the culprit. So, I'm probably not going to align the car yet. I'll get those spring bushings changed and then it'll be alignment time. The fun continues.
-----
Song Huang
1984 633CSi
Last 7 of VIN: 6997383

User avatar
jps635
Platinum Member
Platinum Member
Posts: 829
Joined: Sat Feb 27, 2010 10:50 pm
Location: NZ

Re: 1984 633CSi Rises again!

Post by jps635 » Tue Apr 12, 2022 8:12 am

The bush in the BMW arm, the one with the green insert is a Meyle HD bush. These are like a half way house between stock rubber and full poly.
They are available as inserts and they are generally regarded as a good upgrade (to rubber) - press in. I'm currently running these in Lemforder arms, which PP recommended at the time, having previously had poly bushes which went hard and took on an oval shape.
'85 635csi JPS (RA2-66)

songzunhuang
Platinum Member
Platinum Member
Posts: 1039
Joined: Fri Aug 14, 2015 10:04 am
Location: Silicon Valley, CA
Contact:

Re: 1984 633CSi Rises again!

Post by songzunhuang » Wed Apr 13, 2022 2:51 pm

jps635 wrote:
Tue Apr 12, 2022 8:12 am
The bush in the BMW arm, the one with the green insert is a Meyle HD bush. These are like a half way house between stock rubber and full poly.
They are available as inserts and they are generally regarded as a good upgrade (to rubber) - press in. I'm currently running these in Lemforder arms, which PP recommended at the time, having previously had poly bushes which went hard and took on an oval shape.
Thanks for the info. I suspected that those bushings had been replaced before. I would have just replaced the bushings, except for 2 major reasons. One, I couldn't find anyone with replacement Meyle HD bushings in stock. Two, the dust boots of the balljoints were severely compromised, I tried to clean them out well, reapply lube and replaced the boots with those red poly upgrades. However, although the ball joints didn't seem to have any play, they were not moving completely smoothly. There was some scratchiness in there. I kept the original arms in case I can figure a way to restore them one day. I have one of those sonic parts cleaners and I may give that a go. As it is, my old spare parts bin continues to grow...

BTW, I tried to get Lemforder arms, but as you may have guessed, I couldn't find the pair. All the parts houses I checked only had one side.
-----
Song Huang
1984 633CSi
Last 7 of VIN: 6997383

songzunhuang
Platinum Member
Platinum Member
Posts: 1039
Joined: Fri Aug 14, 2015 10:04 am
Location: Silicon Valley, CA
Contact:

Everything is working!

Post by songzunhuang » Thu May 12, 2022 7:16 am

It has been about a month and several tanks of gas. The car is running great after reflowing the solder joints. With that and the new front suspension parts, it's doing better than ever. It runs and drives very smoothly. I've been slowly tweaking the tie rods to get my alignment the way I want it. I didn't want to pay for another alignment already as I am still considering the replacement of the spring bushings of the front shocks. I hear squeaky noises when I turn hard right. Anyhow, just wanted to capture my experience so far.
-----
Song Huang
1984 633CSi
Last 7 of VIN: 6997383

rhanley 635csi89
Bigcoupe Contributor
Posts: 314
Joined: Wed Sep 10, 2014 12:08 am
Location: Arden, NC 28704
Contact:

Re: 1984 633CSi Rises again!

Post by rhanley 635csi89 » Thu May 12, 2022 11:47 am

Song, look into "life time alignment". Well worth it, I purchase the "life time" when I first got the car 2014 and used the service 4 or 5 times, just to make sure the alignment was correct. Roger
89 635CSiA (11/88 build)
AlpineWeiss II (218)/Natur(0200)
87 L6 635CSI Sold
87 MB 560SL Sold

songzunhuang
Platinum Member
Platinum Member
Posts: 1039
Joined: Fri Aug 14, 2015 10:04 am
Location: Silicon Valley, CA
Contact:

"Reading" the Spark Plugs

Post by songzunhuang » Mon May 23, 2022 6:03 am

I've seen many articles on "reading" the spark plugs. The idea being that you can look at your plugs and tell how your car is running. It's always fascinated me because every time I looked at my plugs, I always thought they were carbon fouled. The tips were very black and that just didn't seem right, but the car seemed to run ok. Here's a picture of the last set of Bosch plugs after 25K miles. Note that the far left plug has already been steel brushed in this picture. The others show more about what's going on. Basically, this is a sign of a car running rich.
Bosch Out.png
Old plugs.
Bosch Out.png (910.77 KiB) Viewed 25 times
After I reflowed my ECU, the car is running so much better. Smoother and no more stumbling. I recently took out the Densos that I swapped in last time and this is what I see now. Nice even burn, no carbon buildup with a light tan/brown coloring. This is what a correct fuel mixture looks like.
Densos.png
After 25K miles.
Densos.png (982.48 KiB) Viewed 25 times
So I wondered if my car would do any better with the Bosch plugs back in there. They are the OEM recommended plugs in the right temperature range. So I cleaned off the Bosch plugs really well, gapped them to 0.030" and re-installed them. Here's the "before" picture. I think they have a lot of life left in them.
Bosch Cleanup.png
Cleaned up old plugs and reinstalled.
Bosch Cleanup.png (979.79 KiB) Viewed 25 times
I'll report my findings after I run these for a while. In closing, I have a helpful hint when swapping plugs. Take out the air cleaner and air flow metering unit. It makes it so easy to work on the plugs. In this picture, you can see the assembly on the ground to the right. It's just 2 nuts/washers securing the air cleaner assembly, then loosen the band clamp holding the air flow metering unit to the rubber accordion boot, unplug the harness to the air flow meter, and then remove the whole thing. There's so much space!
Plug change.png
Remove air cleaner and air flow metering unit for easy access.
Plug change.png (1.68 MiB) Viewed 25 times
-----
Song Huang
1984 633CSi
Last 7 of VIN: 6997383

Post Reply

Who is online

Users browsing this forum: No registered users and 4 guests