If the piston is moving freely - I had similar intermittent symptoms on our LR3 at one point, and it turned out to be the pad backing plates sticking sometimes in the carriers - every brand I'd tried until I got to Akebono were slightly (a few thou) too big, and with the heat expansion and moving a bit more after a hard stop, wouldn't release properly. On every set I ended up having to file the backing plates down slightly... Long shot but might be worth a check as it's quick/easy?
p.s. you keep making me tempted by a 540i that's near here, yours is a lovely looking example
In reply to paul_s0 :
Appreciate that! The pistons were a little grumpy about being depressed but the seals looked to be in good shape. I ordered some reman calipers just now so I'll have the option if I can't find a solution. Hopefully, they get returned as soon as they arrive. It's funny, I don't mind rebuilding my mountain bike brakes but the extra $100 over a rebuild kit is worth the peace of mind for me. Even though a brake failure on the bike would likely be a lot more disastrous for my body.
I'd encourage you to have a look at the one near you. It's a pleasant car that doesn't ask to be driven like an shiny happy person but can move around its weight pretty well. Mine probably owes a lot to golfduke and is at best a 5 footer, but I don't know of anything else that would do the job so smoothly for the price. There are several threads about this car now and not too many quality photos. I hope to remedy this once I get the rear bumper back from paint but here's another lousy one to tempt you
mikeonabikesmith said:
Some combination of worn front rotors, some pulling when braking, and being a sucker for a sale net me a box of Hawk parts. The blank rotors in the front and drilled in the rear was really giving me OCD....
Install was relatively smooth and I kept thinking about how little trouble the car has given me, especially with bolts that just come out when asked. I must have jinxed it. Thought I would bleed the front while I had everything in the air - all good from the passenger side but the driver had a gunked-up nipple. No problem, pulled it out and cleaned it up. But I'm still getting half air/half fluid when using a vacuum bleeder, no matter how much I bleed. With the nipple removed the caliper seems very happy to gravity bleed. Brake pedal feels OK and the pulling when braking is resolved but the brakes will sometimes seize up after a hard stop - not ideal for bedding in new rotors. Appears that the front wheels sometimes spin freely, sometimes lock, and sometimes sit somewhere in-between. I would have thought a rotten piston may be an issue after being recessed back into the caliper, but it's odd that both front calipers are impacted. Especially with freshly lubricated pins and all. Scratching my head on this one.
Old
new
So I did the rears myself and without issue, but rockauto sent me the 'Street performance' package from Hawk rather than just their standard setup due to stock issues. Hence Drilled and slotted rotors. It wasn't worth sending them back and waiting out a lead-time since I had to put them on to pass inspection, so on they went! But I agree- the OCD aspect always annoyed me a touch.
In reply to golfduke :
Funny that they had stock issues then too. My order took maybe 45 days to ship, no biggie for me but I can imagine a touch annoying for someone who really needs brakes.
I futzed more with the stock calipers, even stripping one of my adjustable c-clamps trying to push the piston back just a bit further. Still a bit sticky. My current theory is that there's just enough corrosion on the pistons to where they won't fully recess, and there's just enough thickness in the new pads/rotors that they get hot, expand, and drag. I have no idea if this is reasonable or not but it doesn't matter because I got impatient and put on the reman calipers to be done with it. Definitely more clearance during installation that the OEMs which were a very tight fit. All seems well enough.
Speaking of doing things more than once. I had the car up in the air to install the steering box and figured I would throw in the transmission bushings I had bought with the rest of the shifter refresh bits. These were billed as an "OEM+" feel and cheap enough at $30 something dollars to where I thought it would be a fine replacement. Yiiikes. The car drove great, noise and vibrations were far from OEM. Tried a few times to re-arrange the order of installation thinking I had done something wrong but even with almost no torque holding these down the vibration was bad. Lesson learned. OEM parts were ordered, installed, and an improvement finally felt.
I also got around to fixing a leaky nipple... The radiator was replaced under GolfDukes ownership but a leak developed around this breather. RMEuro had exactly one of these little replacement nipples in stock so I was psyched when it actually showed up.
Here's the part in question, with most of the old coolant cleaned up to make sure there wasn't something else amiss
Naturally, when attempting to pry out the old part with a screwdriver it became two parts. A socket on a string was deployed to release the old assembly
I haven't driven the car too much but I think this was a success. $7 and 30 minutes sure beats a new radiator. We'll see.
i've done over 200k in e39s and e38s, love them
The V8 steering is never as nice as the rack on the I6 cars, but ensuring all the suspension bushes are in good shape takes most of the slop out. I fitted an M5 rear ARB and it just sharpened the turn in up in a good way.
as for running issues. going through all the temp sensors and cam sensors make a world of difference to mine.
They are among the easiest cars to work on. Audis of the same age require most of the front end off to do jobs that would take 10 mins on the e39
That socket on a string idea is great!
In reply to Rigante :
It's funny people seem to complain about working on these because it's a big engine in a pretty big engine bay. Other people complain about working Minis because it's a small engine in a small bay. I'm just happy I've only had to cut one bolt so far, and that was due to bad plastic not rust.
Steering has definitely improved with all the new arms and bushings - I think it's just a couple bushes on the rear arms and control arms up front remain untouched at this point. The m5 steering box has made the biggest difference so far and was a great upgrade at $240 for a <100k box shipped. Part of the reason it was relatively cheap is that it came without a functioning servotronic unit so the car is permanently in sport mode, or something like that. The servotronic essentially offers variable steering assist - I think it's a on/off situation not a linear curve but I haven't done that much research. A few notes if Google brings anyone looking to put an e39 m5 steering box into a 540
- I did not have to drop the subframe. I was able to rotate and tetris out the box with the engine and subframe in place
- The power steering hoses are a pain to unbolt but by loosening and jacking up the steering box they can be reached from the top with extensions and a swivel
- This is an easier job than expected, I had worked it up to be a big thing in my head but it would be sub 2 hours if I had to do it again
- Steering feel with the servotronic unit unprogrammed/unwired is fine. It's maybe 15% heavier than an ancient sprinter van at low speeds but I can park with one hand and I'm in no way worried about damaging splines on the steering column/rack. There's a lot of different opinions on the internet about turning off the servotronic and I don't have a wired unit to compare this to so my opinion is largely useless. However, if I knew wiring the servotronic was not an option I would happily go ahead with the m5 box. I'm going to keep an eye out for an e38 at the local pick n pull to grab a servotronic unit from as they seem to be unobtanium from m5s at this point. If it never happens I won't be upset but I suspect driving under ~20 mph will be a bit nicer when working as intended from the factory.
I didn't take any photos during the process but hey, look how not-rusty it is under there!
it looks great, but I would investigate under all the underbody plastic as they do love to rust, jacking points mostly
In reply to Rigante :
That's fair, I haven't done so and probably should but I've really been happy with what I'm finding so far.
Slow progress continues, rearview camera went in. This was an alibaba unit that integrates into the door handle, and while I don't normally love the very made-in-chine stuff it's not of bad quality. Now my head unit doesn't go blank when I reverse, and I probably won't back my new rear bumper into garbage. Sort of an involved install to run the wiring.
New bumper. Twice painted. Not sure how it made it out of the shop with a massive run but they were kind enough to fix it.
Muffler was removed and replaced with a Turner pipe. Photos without sound don't really do much justice. It's an improvement, technically there's a drone at highway speed but you have to pay attention to find it. Lost some weight at least. I found it hard to track down the right-sized exhaust tip and I worry that the unit that should eventually show up will be a little ricey. But it adds one more "M" logo to what I believe are 10 already on the car.
Old vs. new
All cleaned up (sort of)
Still on the fence about these headlights
One of the best looking sedans every made. Perhaps THE best looking! Great to see you keeping this one going!
I really like the car and how its coming along. If there are two things that bother me are the headlight covers, like you mention, and the black roof. But even then, it looks great.
It's funny to me how many people seem to tuck these cars away for the winter. I guess if this was my retirement fund it would make sense but it's not bad in the snow. If you're already sideways you can't be surprised by a slide...
With cold weather the rough idle returned. I went ahead and replaced all intake gaskets as well as the ccv gasket. They looked to be in good condition but I did discover a vacuum hose from the intake in bad shape. Not 100% sure it's purpose as I haven't found a part number to replace it but the temporary repair is working for now and the car is happily idling on cold days/cold starts.
I did ultimately decide I didn't need to deal with tire rub all winter and sourced some more appropriate tires. And wheels. I may have let vanity get the best of me but craigslist came around eventually
My issue now is that I rather like the car. SWMBO works in health care and has the opportunity to take travel assignments. I work from home and welcome the opportunity to try out a different places for 3 month stints. We're getting pretty close to pulling the trigger on this which leaves me in a weird place on vehicles. The van will come with us, and my wife's car will come with us, but the bmw is pretty heavy to tow. A motorcycle makes a lot of sense to drag along so I'm not driving a hotel room 100% or the time but most of the people in my life get mad whenever I say motorcycle. So I find myself shopping for a Miata or mini, again. Either should flat tow OK. The bmw will either stay home or be babysat by my father back on the east coast. I think a Miata would compliment the 540 just fine when we're presumably back in the house. A NC with hardtop is awfully tempting given the price of hardtops for the nb and na chassis but even those seem pretty spendy. Lots to scheme on
Rear bumper came out good.
Man, I love how youv've just slowly knocked everything off of my bucket list with this car.
IF you ever sell it, I'd respectfully ask for first right of refusal. Selling this car is one of my biggest automotive regrets, but I'm happy that its in good hands.
In reply to golfduke :
Absolutely. I tried to thank you in person a few months back when I was in your neighborhood but all I got out of it was a delicious burger and beer. It's a car that sort of gets under your skin, isn't it?
