Hi,
f10 550i the 6 speed manual (gs6-53BZ) transmission.
When I release the clutch, in first and (a bit less) in second gear only there is a strange sound. It is like a metal to metal low tone grinding sound.
I attached a clip with the sound. it is between second one and second 2 in the clip (volume need to be increased/say max)
https://youtu.be/CTRQBJ06b5U
it is between second one and second 2 in the clip (volume may need to be increased)
The same noise is present when in first gear, and idle rpm (i think it is 750 rpm), clutch fully engaged, it gets extra load due to a light uphill alley to my garage. When I park the car i release the clutch and let the engine at min rpm speed move the car at minimum speed.
Second gear has the similar noise but much lighter. Since i do not start with 2nd gear, and i do not let 2ng gear at min rpm, it is hard for me to judge 2ng gear. All the other gears, are OK.
Initially i thought it was the clutch, so I did not bother. But after i changed the clutch 2 month (and 500 miles) ago, I noticed the noise is still here. Actually, the same noise is there when I put the car in reverse. So, the noise was before the clutch change, and persists after the clutch was changed (note - I changed the flywheel, pressure plate as well, not just the disk)
When the engine/car is cold, the sound is not there. It starts to make the noise once it warms up.
Also, when I changed the clutch, I drained and refilled the transmission with bmw original transmission oil. Fill was done with pump operating, so the oil level is where it should be (ok).
Engine oil is 0W30 full synthetic
Since this is at low rpm <1200 rpm, and when warm, makes me think could be oil too thin in the engine? and the lubrication oil film cannot be maintained between the shell bearing and crankshaft? So they rub metal to metal without the lubricating oil film? Or some bearings in the transmission?
Reason for me to judge that is because when I park the car, after releasing the clutch, the car drives a flat area (still 1st gear, 750 rpm idle, clutch fully engaged) without making any noise. The moment the car goes a bit uphill towards the garage, then the noise comes back. The sound disappears if I take the load off the engine (depress the clutch or gets in the flat area of the garage, .
Should i try 5W40 engine oil to see what's happening?
Opinions welcomed!!!!
Last edited by JohnelP; 03-07-2020 at 11:52 PM.
If I had to guess I’m going to say something is loose and your hearing the sound in first and reverse cause those are the gears with the most strain or power and it’s causing a vibration of what ever is loose because of the increase of strain compared to higher gears.
just a guess, I’d also stick to what your owners manual specs for oil. If it says one grade of oil I would never switch to something different. There’s a reason they Recommend what they do.
good luck
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