New 128i owner with N52 question

[Piper1]

Hi everyone.
We have a lease that's ending soon so I wanted to find something I could buy outright and came upon this 2011 128i for a daily. In the past I've had my 03 z4 as a daily but with the need now for a back seat and the extreme amount of salt my work uses in winter the z4 has become more of a warm weather kind of car.

So my question after 4 days of owning it I'm really pleased with it but noticed the engine seems to have a harmonic hum that is pretty audible when the hoods popped up, and since I'm use to an M54 engine and it's been over a decade since I'd been in a facelift z4 with a N52 in it I honestly can't remember if this is normal and wanted to make sure if this was an indicator that somethings going wanted to get things sorted right away. It's heard loudest from the front near the belt area but I was hoping others might be able to pin point the sound from what they've come across. I do apologize for the video being at night. Thanks a bunch in advance.

Besides that I'm really digging the car so far as a good daily.

[NorthernDancer]

Doesn't sound normal to me [own a 08 128 w/62 K miles]. Try making your own stethoscope out of 3/8ths inside diameter clear vinyl tubing, about 4 feet long, and using it to locate where the noise/hum is coming from. There must be a u tube video of someone doing this.
A BMW or import garage mechanic can give a good opinion within a minute or two. Even another N52 enthusiast.

[Thunderguts]

It definitely doesn't sound normal to me. I assume the pitch changes with RPM. I would try to narrow it down to inside the engine or an accessory. Some possible guesses: belt tensioner or PS pump.

[Piper1]

Originally Posted by Thunderguts

It definitely doesn't sound normal to me. I assume the pitch changes with RPM. I would try to narrow it down to inside the engine or an accessory. Some possible guesses: belt tensioner or PS pump.

Thanks, yeah I was kind of thinking the lines of belt tensioner too even had thoughts of possible water pump, but don't have tell tell signs of a wp going out, pitch does change throughout rpm rang but it's not heard as much inside vs. under the hood.

[b1aze]

Does engine temp change the sound? Cold vs hot coolant/oil?

[Piper1]

Originally Posted by NorthernDancer

Doesn't sound normal to me [own a 08 128 w/62 K miles]. Try making your own stethoscope out of 3/8ths inside diameter clear vinyl tubing, about 4 feet long, and using it to locate where the noise/hum is coming from. There must be a u tube video of someone doing this.
A BMW or import garage mechanic can give a good opinion within a minute or two. Even another N52 enthusiast.

Pending on time for investigating I might just be taking it to the garage as that thought crossed my mind too before posting on here, definitely a good idea on the stethoscope thanks, might actually have some tubing laying around for that too

[Thunderguts]

Originally Posted by Piper1

had thoughts of possible water pump

It shouldn't be the water pump if it changes with RPM. Unfortunately there really aren't any symptoms for a failing water pump.

[Piper1]

Originally Posted by b1aze

Does engine temp change the sound? Cold vs hot coolant/oil?

It's not there at all at start up just a slight pulley squeak until it's been driven

[Piper1]

As an update as I pulled into work popped up the hood and put my ear the oil filter cap it seems the loudest and the ossolations in sound coincide with the drive belt pulleys ie. same spots in rotation according to paint marker spot on the vibration damper pulley. So now thinking oil filter housing/heat exchanger?

[Converted1]

It’s got a click/rotation to it. Do you know if the OFHG/Belt/tensioner has been done?

[tlow98]

Prolly something with one of the pulleys. Get a stethoscope. Highly doubt it’s OFHG related.

[Piper1]

Sorry for the delay. I'm going to post a bigger update soon but noise was from tensioner pulley. But been through bit of drama so more to come.

[Piper1]

So the drama is it did have both leak from the ofhg and valve cover gasket and on further investigation the valve cover and pcv hose were gunked from either sitting or short trips condensation so had to deal with all that with taking it in to my local bmw dealer. (Which they gave me pics of all this to have to deal with the selling dealer on)

The BMW dealer I got it from was an out of state dealer and when contacting them with now having my local bmw dealer with the car apart the out of state dealer once contacting my dealer here asked them "Is it leaking, weeping or seeping cause all used cars leak and we don't fix every leak from cars we sell". My local dealers comment was what does it matter it's leaking and should've been fixed before being sold. When I was told this from my dealer here and contacted the dealer who sold it to me told me the same wtf quote I couldn't even believe come out of his mouth. Even with talking now to the general manager at that dealer I was baffled even he had the same attitude. It took over a week for them to even attempt to make things right and I had my dealer here do the work cause I was now in a pinch with our lease ending to get the car with now the temp 30 day plates expire at my dealer here which were issued at sale date not delivery date so it was over a month buying the car that it was fixed not having the car even a week in my actual possession. The dealer who sold it to me agreed if I shipped the car back they'd fix it no charge but with giving the go ahead after waiting so long it was ready to pick up all work being done in less than a day. In the end I had to cover my dealers labor here and just got a check today from the selling dealer to cover all part cost. In the end the labor cost was $300 more than shipping it back and forth dealing with that head ache. Also while waiting almost a week for a decision we read reviews on their service dept which at best was on the extreme piss poor. And a reason I picked to buy from this dealer was stellar reviews on car gurus to later find out other sites reviews being poor, mainly toward the service dept.

The issues the car had honestly were small and typical of what it is but was apauld with the selling dealers attitude and since it'd gone through their inspection for their service dept to not notice this, or did and not note it on the inspection or disclose it at point of sale is sick. And the dealer that sold it to me originally sold the car to the first owner taking the direct deliver from Germany. Further on car fax report from all 3 previous owners services, this dealer serviced it more than anyone. All 3 owners had done stellar timely manner work and maintenance done on it but with 80% of that total work being done at this piss poor service dept does make me start to worry in the long run.

In the end I'm still liking the car but man it's been an ordeal from day one of having it.

[NorthernDancer]

First of all, many thanks for the follow up info, it's appreciated and not done enough here. It's truly frustrating to try and help someone with a problem and then have them go silent.
I'm sure BMW NA HQ would like to hear of your situation; they may be able to reimburse some money to you. They also would be talking to the selling dealership.
Also I always recommend joining BMWCCA. Among the very many services they provide, they have 3 ombudsman with direct lines to BMW NA HQ to help resolve disputes. They also have 7 technical service advisors. AND, Mike Miller the Roundel tech editor who often answers your e-mails within 24 hours but often within 4 hours.