[thechoson]

2008 328i with 37,000 miles. Recently I took it in for a brake fluid flush, and was told the rear brakes were worn down to 1mm of padding left and needed to be replaced ASAP. So I got that done.

Less urgent, but still something that needed to be done, according to the mechanic: Front brakes (3mm left), belt tensioner replacement (supposedly it was starting to get loose), and oil housing gasket replacement (slowly leaking oil).

Front brakes are odd, my car's maintenance minder tells me I have 8000 miles left on them, so don't know who to trust on this issue. Or will 3mm actually give me 8000 more miles? Seems unlikely.

As for the other items, for now assuming the mechanics were being honest and I do need to replace those items, how urgent are these items (I only drive 4000 miles a year now)? The mechanic would not give me a straight answer on this, just a "uhh... probably should be done sometime".

[bender rodriguez]

The sensor is pretty dead on for pads. You can run it until the sensor says 0. I did.. I wouldn't replace pads with 8k. Might last you another 6 months. Depends how you drive.

The oil housing leak not important if its a small leak. Its also easy to diy. Its right there on top..

[alexwhittemore]

The brakes are definitely fine until the sensor says zero, unless you have some kind of very significant trip planned. They've definitely got a few thousand miles left before dead.

The belt tensioner probably isn't immediately a problem, and it seems surprising that it'd be loose after only 37k, but I don't have much experience there.

The oil filter housing leak isn't REALLY a problem, but if it gets any more pronounced it can leak onto the serpentine belt and cause it to slip. Especially if the tensioner actually IS a bit loose, that may be a significant problem. I think it's quite rare, but some forum members have had issues where a filter housing leak causes the belt to slip off, and in a rare worst-case scenario it can occasionally get ingested into the engine through a bearing or something like that, resulting in catastrophic failure.

I don't know a lot about it, and again I think it's pretty rare, but for how easy and cheap that gasket is supposed to be, I'd get it replaced (or DIY) ASAP.

EDIT: Caveat- if you want to be sure the filter housing actually IS leaking, you might as well clean it up well with a rag and see what comes out over the next few days.

[IN54NITY]

I kinda disagree, I go by my eyeballs and not the computer. 3mm (if it ~is~ truly 3mm) isn't much, especially if you have long hills in your area. (Why? You might get brake fluid fade because when the pads get thinner, more heat goes into the line through the brake pistons.) Edit: also, at 3mm pads can start to crack and when they do that they really disintegrate rapidly. If you drive 'round the flats 3mm isn't pressing, but I would get it done within the next 2k miles.

A leak is a leak, fix it, and it's true, it's very easy to replace.

Belt tensioner may last to your 50k, that's the one I would postpone a bit.

[335idle]

I'm an SA at Acura. I can't believe they let you leave the dealer with 3.0mm pads.
If you crash/ hurt someone you know why.

Don't play with your life or others.

[bender rodriguez]

Originally Posted by 335idle

I'm an SA at Acura. I can't believe they let you leave the dealer with 3.0mm pads.
If you crash/ hurt someone you know why.

Don't play with your life or others.

Oh god...the computer says he has 8k left. The sensors are pretty accurate and I run my pads until nothing is left. If he only drives 4k a year that's 6 months to a year of pad. No need to waste money.

[J-Spec Dan]

at 3mm, your electronic wear sensor will probably illuminate soon. replace sooner rather than later. don't wait until you have nothing left.

[bender rodriguez]

Originally Posted by J-Spec Dan

at 3mm, your electronic wear sensor will probably illuminate soon. replace sooner rather than later. don't wait until you have nothing left.

Yeah in 8000 miles

[J-Spec Dan]

Originally Posted by bender rodriguez

Yeah in 8000 miles

not necessarily. electronic wear indicators tell you when you're close: 1-2mm remaining.

[Kwike92M3]

The sensor on your dash is an estimated time measurement, not a real reflection of life left on pads. There is not way to measure that through a set of brake pads. The sensor that throws the signal that you need brake pads is a simple ground and power signal. Once the pad wear sensor is broken by pads worn low enough, it will trigger the dash indicator. If you drive the car more aggressively, ride the brakes, or drive in hilly areas, etc, then your pad life can decrease significantly. I always suggest a physical brake check to my customers, no matter what the dash reads. Some customers can go up to 100k on factory brakes, some dont make it past 30k.

If a tensioner is truly loose, it will usually make bearing noise of some sort. Dealerships are notorious for suggesting tensioners and idler pulleys when they are not needed. I typically see idler and tensioner play around the 50-60k mark on BMWs, which is right around the time the first set of belts are needed. Do your tensioner and belts @ the same time to save some labor cost.

Any oil leak should be addressed before it gets serious. Oil filter housing adapters typically dont leak very fast unless it has reached extreme circumstances. Get it replaced when you can. It is a relatively simple repair, the part needed is VERY cheap, so this may be an opportunity to get dirty and learn your vehicle.

Just my two cents.

[bender rodriguez]

Originally Posted by J-Spec Dan

not necessarily. electronic wear indicators tell you when you're close: 1-2mm remaining.

Yeah but its not going to go from 8k to zero overnight. I find the I drive computer to be quite accurate. No reason not to trust the sensors and I drive estimate

[Efthreeoh]

Okay so let's get specific here. The brake wear system in the E9X chassis has an estimated brake pad life notification in the CBS. If the car is operated consistently then the estimate provided by the CBS is fairly accurate. The brake wear system also has a failsafe notification that illuminates the "BRAKE" light in the gauge cluster and it remains on until the pads are replaced and a new sensor is installed. Unless there is a situation where a caliper is sticking and wearing out the pads prematurely (possibly on the side were there is no sensor) you really only need to pay attention to brake replacement once the "BRAKE" light illuminates.

If your mechanic was honest with you and the rear pads were near minimum thickness and about to trigger the sensor then you didn't lose much mileage (useful life). That said, once the "BRAKE" light triggers, there is sufficient pad material left for a few thousand miles to schedule a brake service. There is no need to panic about thin pads. In reality even if a pad is completely gone and the backing plate is eating the rotor, the car will be able to safely stop (since the other 3 brakes are probably not metal to metal), but it will be quite noisy.

[hockeyplayer]

You can probably wait on the brakes for a bit, depending on driving conditions, etc. of course.

Check out the oil filter housing gasket DIY. If you aren't handy like that find a friend who is and get them to do it. Don't pay outrageous dealer prices for something that will cost $10.

good luck

[bender rodriguez]

Originally Posted by hockeyplayer

You can probably wait on the brakes for a bit, depending on driving conditions, etc. of course.

Check out the oil filter housing gasket DIY. If you aren't handy like that find a friend who is and get them to do it. Don't pay outrageous dealer prices for something that will cost $10.

good luck

Yeah the dealer charges what 250.00 to do it right?

[J-Spec Dan]

Originally Posted by bender rodriguez

Yeah but its not going to go from 8k to zero overnight. I find the I drive computer to be quite accurate. No reason not to trust the sensors and I drive estimate

for sure. I'm not saying to replace them now. just to be aware and replace them before getting down to the absolute minimum or zero friction material.

[Eat.Sleep.Race]

Wait for brake light to come on, then replace.

Belt tensioner i would do soon, if its not super expensive.

Oil leak, can do yourself, look up the DIY.

[Efthreeoh]

Originally Posted by kwike92Msport

The sensor on your dash is an estimated time measurement, not a real reflection of life left on pads. There is not way to measure that through a set of brake pads. The sensor that throws the signal that you need brake pads is a simple ground and power signal. Once the pad wear sensor is broken by pads worn low enough, it will trigger the dash indicator. If you drive the car more aggressively, ride the brakes, or drive in hilly areas, etc, then your pad life can decrease significantly. I always suggest a physical brake check to my customers, no matter what the dash reads. Some customers can go up to 100k on factory brakes, some dont make it past 30k.

Just my two cents.

This is incorrect. The E9X system has two loops of wire in the sensor. The first loop, once broken, helps determine the estimated pad life remaining. Breaking the second loop triggers the "BRAKE" light indicating the pads (for a specific axle) are in need of replacement. The CBS will read "--" for the axle that the pads are spent.

[bender rodriguez]

Originally Posted by Efthreeoh

This is incorrect. The E9X system has two loops of wire in the sensor. The first loop, once broken, helps determine the estimated pad life remaining. Breaking the second loop triggers the "BRAKE" light indicating the pads (for a specific axle) are in need of replacement. The CBS will read "--" for the axle that the pads are spent.

That would explain why the I drive is so accurate

[hockeyplayer]

Originally Posted by bender rodriguez

Yeah the dealer charges what 250.00 to do it right?

I would think $250 would be cheap for a BMW dealer lol

[bender rodriguez]

Originally Posted by hockeyplayer

I would think $250 would be cheap for a BMW dealer lol

Isn't it only an hour of labour and 150 dollar part or less?

[drewnel22]

Originally Posted by 335idle

I'm an SA at Acura. I can't believe they let you leave the dealer with 3.0mm pads.
If you crash/ hurt someone you know why.

Don't play with your life or others.

I hope you are joking... Just because he has a little bit of pad left doesn't all the sudden make his car unsafe. It will be ok.

Replace them if you feel unsafe but you are just throwing money away prematurely.

[IN54NITY]

Originally Posted by Efthreeoh

This is incorrect. The E9X system has two loops of wire in the sensor. The first loop, once broken, helps determine the estimated pad life remaining. Breaking the second loop triggers the "BRAKE" light indicating the pads (for a specific axle) are in need of replacement. The CBS will read "--" for the axle that the pads are spent.

And I disagree with you on your first sentence, the rest I agree with and is true, but why do you say this is incorrect when in your own words, you write:

Originally Posted by Efthreeoh

Okay so let's get specific here. The brake wear system in the E9X chassis has an estimated brake pad life notification in the CBS. If the car is operated consistently then the estimate provided by the CBS is fairly accurate. The brake wear system also has a failsafe notification that illuminates the "BRAKE" light in the gauge cluster and it remains on until the pads are replaced and a new sensor is installed. Unless there is a situation where a caliper is sticking and wearing out the pads prematurely (possibly on the side were there is no sensor) you really only need to pay attention to brake replacement once the "BRAKE" light illuminates.

...

Also what about "not just premature wearing", but if the other side had some crap between rotor and pad at some point and the pad started to crack and disintegrate (I've seen this numerous times when pads are less than 3 mm, especially when at 1mm) ?

OP, use your eyeballs and look at both front left and right pads (even then you can't see the pads on the inner side of the rotor) and verify that they are 3mm. There won't be much room to see because at that (small depth) the backing plates will block your view. (It will almost look like your backing plate is on the rotor.)