Serious Brake Problems X5M

[chris604]

HI all,

After a track day, last week, the warning lights came up on the dash, one after the other, parking brake malfunction, stability error, abs fault, and more. And, the power steering just stopped working! Also, after driving it insanely hard, the rear tires came apart on the inside and wrecked the wheel well cover, and there were all these tiny yellow wires, and some were broken, so I tied them together, and bam, all the lights came off, and the truck drove fine, and the power steering started working again. Well, a week later now, and it's acting up again, the same lights came on, and threw some weird codes like p15c9, p1505. and the power steering just doesn't work again. I checked the wire and it's fine. But, I should probably just rewire it properly. But, the wires are extremely small, and I couldnt' find any marette or anything to splice it together. Or could it be something unrelated to those wires? The wires were in the passenger rear wheel well up under the wheel well cover. Also, I did flush the brakes myself, and didn't bleed the abs or anything like that before I went to the track.

Thanks!

[Thecastle]

My 1st though based on the dash and description is a bad alternator and or battery. Usually you see the Christmas tree dash when the battery and or alternator dies. Mine alternator seems to go every 40k miles.. also check for belt slip, driving hard may have glazed the belt and or exposed a bad tensioner.

Anyway this is what you typically see when you disconnect the battery and then start the car.

Any pictures of the wiring damage?

[Colodano]

With how sensitive the electronics systems are on these rigs, I would say do a full proper repair or replacement on that harness first, as it was a known issue, and sounds like a track day quick fix. Maybe something pulled loose enough to lose contact but still appear to be ok etc.

[chris604]

Originally Posted by Thecastle

My 1st though based on the dash and description is a bad alternator and or battery. Usually you see the Christmas tree dash when the battery and or alternator dies. Mine alternator seems to go every 40k miles.. also check for belt slip, driving hard may have glazed the belt and or exposed a bad tensioner.

Anyway this is what you typically see when you disconnect the battery and then start the car.

Any pictures of the wiring damage?

Yep, here it is. Just the yellow wire was cut, so I put a marette, and taped it and it worked fine for a week. now doing it again, just tried to see if anything else was broken. just some stripped yellow wires. The shop that I called said it was probably airbag wires, but still not sure.

still the same error. Charged the battery overnight. if it was the battery, wouldn't it not start or have a warning light. The dealer says it was the batter and to charge overnight. lol. did that, same thing

[chris604]

Originally Posted by chris604

Yep, here it is. Just the yellow wire was cut, so I put a marette, and taped it and it worked fine for a week. now doing it again, just tried to see if anything else was broken. just some stripped yellow wires. The shop that I called said it was probably airbag wires, but still not sure.

still the same error. Charged the battery overnight. if it was the battery, wouldn't it not start or have a warning light. The dealer says it was the batter and to charge overnight. lol. did that, same thing

Well, just put on some brand new tires and rims. Old ones were shot from the track day, lol. Did 1:20.8 at mission raceway on crap tires with a misfire and spongy brakes. working on that misfire problem too. Only comes up during track day unfortunately, and the spongy brakes should be fixed with a flush and bleed at the shop.

These are the rear tires after track day. Nothing left at all, and bent one rim too. I had to seriously pound the curbs on the track to get a decent lap time:

[chris604]

Originally Posted by chris604

Well, just put on some brand new tires and rims. Old ones were shot from the track day, lol. Did 1:20.8 at mission raceway on crap tires with a misfire and spongy brakes. working on that misfire problem too. Only comes up during track day unfortunately, and the spongy brakes should be fixed with a flush and bleed at the shop.

These are the rear tires after track day. Nothing left at all, and bent one rim too. I had to seriously pound the curbs on the track to get a decent lap time:

OH, and I played with the wiring some more, and took it for a test drive. All warning lights gone on the dash, and power steering is miraculously back and running fine! brakes fine.

[Colodano]

Damn, you did a number on those tires!

Obviously pushing it on a track will bring out the issues in anything, hopefully your misfire is just old plugs, or worn coils. If you are tuned, may be needing a set of colder plugs in there.

[chris604]

Originally Posted by Colodano

Damn, you did a number on those tires!

Obviously pushing it on a track will bring out the issues in anything, hopefully your misfire is just old plugs, or worn coils. If you are tuned, may be needing a set of colder plugs in there.

haha yeah. Well, replaced all the vacuum lines (4 anyways) and still misfiring cylinder 6. replaced coil. same
only when I push it at the track does it do that, and then just goes to limp mode. And, I get the leak codes, so maybe air leak still? fuel leak>? I smell gas when I start the car like 50% of the time, so that's another issue as well. that the dealer never fixed.

[frankenm]

Originally Posted by chris604

haha yeah. Well, replaced all the vacuum lines (4 anyways) and still misfiring cylinder 6. replaced coil. same
only when I push it at the track does it do that, and then just goes to limp mode. And, I get the leak codes, so maybe air leak still? fuel leak>? I smell gas when I start the car like 50% of the time, so that's another issue as well. that the dealer never fixed.

You should never smell gasoline this is a sign of a fuel leak somewhere .... just me but I would never drive a car with a possible fuel leak or hints of gas smell unless I literally just had the fuel tank open and knew exactly where it was coming from it is extremely dangerous because of the vapors and possible ignition

[chris604]

Originally Posted by frankenm

You should never smell gasoline this is a sign of a fuel leak somewhere .... just me but I would never drive a car with a possible fuel leak or hints of gas smell unless I literally just had the fuel tank open and knew exactly where it was coming from it is extremely dangerous because of the vapors and possible ignition

It's been doing that for a while. And, I get the 'tighten gas cap' error coming up all the time. Took to the dealer, they replaced the gas cap, same thing, LOL. I figured they would detect some sort of problem. It also came up with a bunch of codes related to the fuel evap and gas cap issue, but they didn't do anything. Any ideas on that? It does it randomly, just on startup. Smell a little gas sometimes, then goes away right away. Also, I have that annoying misfire, on cylinder 6, that only comes up when I stomp on the loud pedal a lot, otherwise, drives perfectly fine. Maybe it's a fuel issue causing the misfire?

[chris604]

Originally Posted by frankenm

You should never smell gasoline this is a sign of a fuel leak somewhere .... just me but I would never drive a car with a possible fuel leak or hints of gas smell unless I literally just had the fuel tank open and knew exactly where it was coming from it is extremely dangerous because of the vapors and possible ignition

Also, just got a stability error on the dash, this time in RED, vs the yellow that I had in the pictures above. Turned off the truck back on and it was fine again. Is that system failing, or is it still a bad connection in the wiring?

[0-60Motorsports]

Check your injectors.

[Thecastle]

Originally Posted by chris604

haha yeah. Well, replaced all the vacuum lines (4 anyways) and still misfiring cylinder 6. replaced coil. same
only when I push it at the track does it do that, and then just goes to limp mode. And, I get the leak codes, so maybe air leak still? fuel leak>? I smell gas when I start the car like 50% of the time, so that's another issue as well. that the dealer never fixed.

I've been chasing a similar set of symptoms as well (no misfire though). I get a reduced power limp dick mode after towing a trailer for a while. Its only under sustained high loads that I get a problem. Typically when going up hill at highway speeds I get the chime of death of my nightmares and my favorite half engine picture. Towing is similar to your case where your running the car under track conditions.

Not a misfire for me, but I get leak codes as well. I've had a smoke test done, replaced all PVC lines, Filtered Air ducts, MAP sensors, pnemuatic pressure converters, and etc. Chasing this 30FF error. The best guess at this point for me is a weak turbo. I find though keeping the car in a lower gear (5th) while towing avoids the issue. I'd suspect your misfire maybe a bad injector or a problem with the evaporative emissions.

I also get wiffs of gasoline bad, taken it to the dealer several times for this issue. They've replaced the tank pressure pump, Charcoal canister and no dice. Its a mystery as it dosent happen all the time.

[frankenm]

The fuel lines are easy enough to access just run through each injector and pump.

Chasing this 30FF error.

classic bmw turbo error... your wastegates are probably bad if you have done this much and still happening - you can adjust them yourself unless they are shot completely

[chris604]

Latest track day in my X5M in the rain. Lots of fun:

[Thecastle]

Originally Posted by frankenm

The fuel lines are easy enough to access just run through each injector and pump.



classic bmw turbo error... your wastegates are probably bad if you have done this much and still happening - you can adjust them yourself unless they are shot completely

Yeah my guess a this point is marginal turbos. Also hard to say which turbo is the weak one. Tweaking the waste gate may help or may not depending on what’s wrong. The actual procedure to do this without guessing and causing other problems seems rather time consuming.
https://dsportmag.com/the-tech/how-t...in-turbo-duty/

Or is there an easier way?