1984 633CSi Rises again!

[songzunhuang]

So after lots of poking around, I am going to an exhaust shop to see if it's possible to replace the kinked section of my down pipe that is causing my entire system to shift forward about 1 1/4" inches. The pipe is in a pretty accessible area and the pipe bend doesn't look too complex.

Damaged downpipe

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For now, I have a janky solution of hose clamps keeping my exhaust from clanking around beneath me.

That'll do for now. Clamps.

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As for a muffler, I was able to meet up with Ralph on one of his trips up to NorCal and get a Bosal muffler that is in good shape to replace my busted one. It'll be nice to get rid of the droning from the exhaust that I hear when driving these days.

Replacement exhaust from Ralph

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I'm not sure, but it looks like a dead ringer for my original exhaust. I'll know more later this week.
Meanwhile, the driveshaft u-joint situation takes a back seat.

[songzunhuang]

After a few weeks, I have finally completed the repair of my exhaust and also replaced my trashed OEM muffler. It took two visits to an exhaust shop to get it almost 100% right. Here's the story in pics.

The shop had to drop my old exhaust to evaluate whether or not it was fixable. Here's the old system just hanging and ready for inspection.

In position for inspection.

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After removing the heat shield and seeing that the original German stainless was in good shape, they cut the kink and fabricated a new section that gave me my 1 1/4" back and returned everything to a smooth flow. Here's a picture of the entire system on the "operating table". You can see the replacement muffler that I got from Ralph at the bottom of the table and the section they cut out.

Evaluating and planing the cuts.

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Here's the new section test fitted in the car. Recall the kinked section in the previous post. After verifying that it looked good, they tack welded it all in place. My new setup won't have the heat shield in this area, but I think we'll be fine.

Making sure it'd all work.

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Then they had to measure and cut the muffler section and then flare the ends to go over the existing pipes. After all was well, it was quickly welded into place. The alignment of the muffler and pipes took hours. They took their time to make sure all clearances were good and that my tips lined up. They were "wonky" at first. Here's what it looks like all back in the car.

Muffler is in!

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This took the better part of the whole day and the shop was closing and it was time to wrap. Turns out that the welder requested to get the car back in the shop again to improve and clean up the welds. As it stood, it was good enough for me to drive home. So I did. Driving to work today, I enjoyed a very quiet and drone free drive. All is well and my exhaust and muffler should last a long long time.

[songzunhuang]

Well I had a collection of parts that I've built up over the months and it was time to put them on since I had some good weather over the weekend. As usual, there were some wins and some not so good things. Here's a summary.

I started with the replacement of my passenger door trim top piece. Mine was cracking in 5 spots and I finally got a replacement. This should have been an easy replacement right? Well, when I held up the replacement piece, I discover that the door handle attachment was VERY different. All else looked the same. So out came the dremel for some "customization". In the end it all worked out, but my 15 minute job turned into hours. It wasn't a simple plastic cutout. It was all backed my metal. The bottom picture has the new piece installed.

Before and after cutout.

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Next was some service on my front strut. I thought that there was a squeaking noise when I turned left and right and the car was stationary. I figured I would replace the front strut bearings and the spring seats. Well, this was an exercise in frustration. The Corteco front bearings would not turn after installation. They were tight. This was not right as the originals would freely turn when installed. So after disassembling and assembling, I had to take it all apart again and reinstall the originals. Not only that, I noticed the upper spring seats I got were thinner than the ones that were there. I decided to reuse my existing ones, which I think I replaced a long time ago. Anyhow, After all the work, the only thing replaced was the lower spring seat. Oh, and the squeaking is still there...

All this was for nothing.

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I guess the good news was that my original bearing strut bearings seem good still with no play. I cleaned them out and put some CV grease on them before reinstalling. I didn't bother with the driver side after my experience with the passenger side.

So next was something that was "easy" I got some little plastic caps for my front rain guides. That should be easy right? Well, it appears the heads of the screws that were in there were too big and interfered with the caps. So I spend a long time digging for a replacement screws. I did finally find them after going through every nook and cranny of my garage!

Wing caps to clean up the look.

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Finally was the hood light. Mine had crumbled apart and I epoxied it back together, but it was old an yellowed. These are NLA so after lots of looking, I was once again saved by Ralph, who had some available! I am glad to report this part went well. No issues at all.

This looks better and was easy to install.

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A final mention is that I got an OEM wheelcap wrench for my BBS wheels. It was really nice, made of some tough impact plastic resin. I understand why it was $27. I am actually really happy with it.

OK, now I have to go and return a bunch of parts I can't use. So that wraps up this weekends activities.

[Slownrusty]

I've been trying to find those rain gutter fastener caps for a while, thanks for the part number and sharing.

Awesome progress!
Yasin

[songzunhuang]

I've been trying to find those rain gutter fastener caps for a while, thanks for the part number and sharing.

Awesome progress!
Yasin

Yasin, I got them from Pelican parts. They were $3.71 each.

Nice cleanup part.

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Also, my old muffler was trashed. I grabbed and it kind of tore it apart by hand! Five years ago I pulled out a set of those tubes with holes in them (I forget the name) and welded the pipes back in. It was OK for a while, but clearly there was no saving it this time.

Missing a set of those tubes with holes inside.

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I'm very happy with my quiet cruiser now. Here's a better shot of the replacement muffler. I realized that the heat shields were missing. I picked them up from the exhaust shop and will put them on another day.

Replacement muffler from Ralph.

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[songzunhuang]

This is a most boring post. The shark is performing admirably, but I wanted to report something that makes no sense to me. I am now getting close to 24.5 miles per gallon! I've driven this car for over 8 years now and I've never gotten better than 22 miles per gallon. I used to get real nervous whenever my odometer showed close to 300 miles on a tank of gas. I had lots of fuel gauge issues in the early ownership years.

So imagine my surprise when I am getting well over 300 miles between fill ups! Last night as I pulled into a station to refuel, here's what I saw.

How is my MPG going up?

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With 313 miles showing, the fill up took 12 gallons. At $5.44 a gallon in California, it was $65.
Has anyone else seen their mpg get better with age?
Perhaps my new muffler has something to do with it? I mean, it's the only thing I've changed lately.

I have failing clear coat on my trunk. That may be my next ToDo, but it's cosmetic so not urgent.

[hornhospital]

Did California change fuel formulation recently? I know the winter formulation is notoriously bad. Maybe the switch to summer blend has helped? Just my wild guess.

[tschultz]

I had similar mileage on my commute a decade ago in my e28...

I thought it was something with an old o2 sensor but my mileage went down when I changed jobs and started seeing my commute and highway driving go down. Now I am having trouble getting over 22mpg when I had been able to average 25mpg on my 55 mile commute...

I have it all tracked via fuelly too. Sounds like the exact opposite. But I did change my exhaust muffler as well around the same time and after putting the original back on, I had the same issue and could not get back to the 25mpg.

Enjoy it while it working!

My best tank was something like 370miles before refill!

[K1W1]

I wish. My M635 does about half that ... :)

[RossDinan6]

I have been tuning mine a bit lately in an attempt to improve milage. Not that it really matters with the miles I put on the car.

So far went from 14 to 16 mpg. It would be better but my brain orders my right foot to increase the boost more than necessary. I got 9 back when I was tracking the car.

[songzunhuang]

Last 2 tanks of gas has me averaging 25.8 mpg!
I reset the calculations each time to make sure there wasn't a weird anomaly.
It really makes no sense, but I guess I'll just enjoy it while it lasts.

[Ralph in Socal]

Likely fixing that bend in the exhaust downpipe made drastic improvements in your exhaust flow. Muffler may have also been blocked from disintegrating inside

I'm getting 27 mpg in the e34 535 manual with 3.46 gears. 3.25 gears would make it better

Ralph

[songzunhuang]

Likely fixing that bend in the exhaust downpipe made drastic improvements in your exhaust flow. Muffler may have also been blocked from disintegrating inside

I'm getting 27 mpg in the e34 535 manual with 3.46 gears. 3.25 gears would make it better

Ralph

All likely issues that have been remedied! I'll continue to keep an eye on anything that may explain this. Overall, the car is running admirably. I like these periods of bliss. "Knock on Wood".

[sansouci]

You lucked out with that Bosal muffler from Ralph.

[songzunhuang]

Well, I guess parking my car outside in the sun has it's drawbacks. It's time to refresh the paint. In preparation for this, I purchased a new BMW emblem ($200, yikes!) and I needed to remove the badging. First order of business was the measure it so that I can put it back in the right place after paint. Note how badly the clear coat is failing.

Getting the measurements for later.

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Then I had read that the emblems are simply glued on. Turns out, it's foam tape, but it's really stuck. I used some dental floss and goo gone and it worked well.

It really works with floss and goo gone.

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This is what I have left now. I am wondering how to put it back on. The foam was precisely cut and placed under the emblem Will I be able to match that? Anyone done this before?

The aftermath,

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Well, first I am going to turn my attention to the trunk. Similar to my roof, this is a repaint and not just a clear coat repair. I may fix a few other spots while I'm at it. More to come.

[songzunhuang]

Well, this past weekend was dedicated to fixing my badly failing clearcoat on the the trunk and some of the surrounding areas. The only solution was a repaint, so I broke out the trusty SprayIt gun and Cromax paint. Here's a greatly abbreviated update in pictures.

First, this is what I was dealing with. Every few days more flakes off and it looks like a cancer on the car. Not only that, my BMW badge finish was also flaking off making everything look janky.

In the beginning, the sad state of the paint.

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Now, paintwork is mostly sanding. I spent a good 7 hours on Saturday just sanding. I was trying to keep everything smooth by starting with 220 grit. That was a mistake. The paint on the car was tough! Next time, I'm using 80 or something aggressive to get the old paint off. I wasn't going to metal, but to the original light colored primer. I was going to prime again, but the original primer wasn't failing at all. For this stage, I used a hand sander.

This took way longer than it should.

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After the sanding I shot my Nason primer using a 1.7mm tip on my spray gun. Afterwards, I realized I should have sprayed the primer much heavier since it was a 80 degree day and the primer wasn't laying down smoothly. It was textured like orange peel. That meant a lot more sanding. When I finally got it smooth with 800 and then 1500 grit, I laid the color coat using a 1.3mm tip and the Cromax paint system. It's great paint and since I already had primer from last time, I just had to get color basecoat and clearcoat. It was about $287 all in. Here's a picture after 3 color coats and the first clear coat. I would lay down 2 coats of clear.

First clearcoat.

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It was tricky doing the blends and I had to go back and repair a few lint particles and a gnat that flew into the wet paint. That meant more sanding and spraying. There was also flaking around the windshield rubber and also the C-Pillars. Finally, antenna hole paint had chipped, so that needed a bit of metal work and then paint. There were lots of tricky areas to blend. Late afternoon Sunday, I realized I was running out of time. So I sanded 1500 and then 3000 grit before polishing. It was really satisfying to install the new badge and admire the rear of the car.

This will do for now.

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I drove the car to work today and stared at the new trunk in bright daylight. It looks pretty good, but I think I'll need to sand and polish again. I can see a few spots that are not smooth. What did I learn? Use the proper temperature reducer for the paint if it's warm. My paint was drying too fast causing orange peel. You could also spray with less air pressure and lay it on wet, but then you risk runs. It's too bad I don't paint more often. I always realize after the fact a few things that I would change. In the end from 5 feet, it looks fine.

[86_6series]

Bravo!! Looks great for a DIY job.

[GRNSHRK]

^^^ That's what I was thinking

Painting is one of the things that I can't do, unless it's in a rattle can

Well, not completely true, as I do use the PreVal setup for spraying interior pieces, which worked well

Nice job, Song

[tschultz]

Great work, you made it look easy with so few photos!

I have contemplated similar on various different cars but haven't gotten to it with the concern of the chemicals and improper PPE for spraying anything larger than what you did there.

[songzunhuang]

Bravo!! Looks great for a DIY job.

Thanks. Each time a learn a lot and think of what I'll do next time.
See that red Volvo wagon in the background? I refinished a LOT of that car in the garage. That was a "practice" canvas.

[songzunhuang]

Great work, you made it look easy with so few photos!

I have contemplated similar on various different cars but haven't gotten to it with the concern of the chemicals and improper PPE for spraying anything larger than what you did there.

I did use a pretty heavy duty respirator. The 2 part paints are pretty nasty, but manageable if you do sections at a time outside.
I have some more to do with the front cowl under the windshield and the top edges of the doors where there's evidence of more clearcoat failing. SIgh, it never ends.

[slfan]

Very interesting and educational thread. Thanks for sharing.