navin

I get a slight knocking sound coming from the engine at speeds below 40mph on the 2nd and 3rd gears. Does not happen on idle and goes away after 30mph.
Took it to the dealership and they heard it too but are not able to figure out what it is exactly after 5 hours , Anyone here experienced anything similar.
I know miguex had something similar but that was on idle, Also the sound appears only after i have driven for 10 miles or so.

550i now

yep, my 545i made similar noises, and I noticed in the last day, my 550i does as well.

Think this is just a beautiful verification of the multi valve engine these cars enjoy.

No big deal, just change oil as suggested.....

navin

The dealer called me and said that there was more than 16% alcohol in my gas
They want me to finish this tank, run it as low as possible and add a techron additive when i fill up next time.
Has anyone else heard of something like this or are they bs'ing because they're not able to figure out he issue?

navin

anyone ?

meatzorb

You can search my posts. Hard to say if it is the same noise but I have dealt with a knocking noise just about every morning. Happens mostly out of my neighborhood as I am usually in 2nd and 3rd ( auto) and the noise is noticeable at about 1800 to 2200 rpm. I call it a knocking noise but sounds just like lifter tap.

Mine is a '04 545i. I have had for 1 year and it is a CPO vehicle. They have looked at the engine a total of 8 times. ruled out all the obvious stuff from TSB and its still there. More apparent when on the first drive-off of the day. Notice I saiud drive off as the sound is usually there when driving. If I hold the pedal at idle the noise is there but not like when underload.

3 times they said it was gas untl I threw in the BS flag, THey were questioning on what I was putting in since Premium was 4.30 gal at the time. So I gathered all the receipts ( I drive for business so have all receipts) 90% of them were Shell premium.

It is worse when it is colder out. The sounds does go away for me after about 20 minutes of driving. I even had the regional BMW rep look at the car in which he replied it is normal, that it is the lighter Al parts having to heat up that is why the noise goes away when it is warm. He said. " It takes a lot of BMW engineering to get a luxury sound and idle coupled with 330HP from a 4.4. liter and the noise is a side effect.

Anyhow I wasn't prepared to purchase a CPO'd 545i and have this engine noise that I am stuck with now. It embarrasses me when other people are in the car and it can even be heard outside the car as i accelerate. ( Once again fr the first 20 minutes of driving)
I'm attaching my recording. This is a mic under the hood on first drive off. Takes a few seconds sound starts about 20 seconds or so ( wait for the knocking not the fuel injector clicking)

silvergray5456spd

i have the same problem with my 545i sport with only 25k on the clock. all it is on a cold start, the oil in your motor is thicker and the oil does circulate up to the lifters very well. as the engine warms up the oil can circulate better. its nothing to worry about just give your car a few minutes in the morning to warm up.

meatzorb

I respectfully disagree on the theory that the oil is thicker when cold. Most vehicles are now running 5W - 30 synthetic and the pour properties at colder temperatures is outstanding. The oil is thinner and flow better at the colder 5W than when it heats up.

I live in Florida so when i say my problem happens at colder temps it is closert to 60 degrees. If anything the colder thinner 5W is creating the noise as it is too thin to maintain pressure in the Vanos ( THis is my opinion)

Bottom line is that it should not be happening. Metalic noise means that metal is rubbing or coming in contact with each other and that means wear to me.

Had the dealer been upfront and disclosed that the engine would be tapping in colder weather I would not have purchased the car. I had over 12 BMWs to chose from. So yes I am still a little "bent' over the subject.

BMW NA has been non-responsive with professional communications. And it has been determined by BMW NA that even though they don't know exactly what it is or what is causing it that there is no harm or shortness of life expected.

silvergray5456spd

Interesting. when i have some time to spare, i will contact Moblie and Castrol about the thickness of the oil when its cold. its hard to believe that certain oils can flow better when they are cold. if you remember way back to science class, molecules move faster as they heat up. as they get colder they "slow down" that theory has been around for years, and its hard to believe that the oil companies can flip it around. just my opinion.

navin

I'm experiencing the sound when it heats up more than in the morning.
My first drive off is perfect and smooth but after about 10 miles is when the knock kicks in
and it is not present at idle at all, not even under acceleration on idle.

silvergray5456spd

Wow thats weird. im not sure what to tell you. maybe take it to a different dealership?