Does every 6MT make this sound?

[mackeroni]

Originally Posted by Dackelone

It's completely normal. You can change your trans fluid... that might hide it somewhat. But it is a normal sound for our cars.

Btw... I would be changing your trans and diff fluid at least every 60K miles. I change mine at least every 30K. Sometimes sooner - bc it looks so nasty even at those intervals. I used to use Red Line ATF-D4 and now I am using RL MTL in my manual trans.

Dackel

What fluid do you use in your diff? I am thinking RL 75W110.

[iminhell1]

Originally Posted by mackeroni

What fluid do you use in your diff? I am thinking RL 75W110.

LSD - BMW OE fluid
Stock open diff - anything you want the friction coefficient isn't important.

[chris_flies]

Originally Posted by mackeroni

What fluid do you use in your diff? I am thinking RL 75W110.

OE BMW is 75W-90...

-90 is the standard, which allows a bit more noise from the diff, and will maintain factory-like fuel economy..

-110 is thicker, which reduces noise and wear from/in the diff, but may marginally reduce your fuel economy...

I have a mix in mine, it works fine. You don't need any Friction Modifiers, unless you have a clutch-type LSD (or if the diff requires it).

[Stubbie Blue]

Originally Posted by iminhell1

Look up on Youtube something like "engine pinging" and see if that is anything like what you're hearing.
Sure sounds like it should be, and the conditions you're describing fit.
In the case of our cars, you're lugging the engine too much and causing minor preignition. You are much safer to downshift and use more RPM than you are to lug the engine with high load/low RPM.

Can this happen with no throttle when coasting down through the 1500 rpm range? Because that's when I sometimes hear it. I thought pinging or knocking happens at high load and the rpm is too low, and I have had that happen in my other car, an Audi with a 2L turbo 4 cyl.

[iminhell1]

Originally Posted by Stubbie Blue

Can this happen with no throttle when coasting down through the 1500 rpm range? Because that's when I sometimes hear it. I thought pinging or knocking happens at high load and the rpm is too low, and I have had that happen in my other car, an Audi with a 2L turbo 4 cyl.

A coasting situation I'd look more to a chain guide/tensioner. Datalog oil pressure vs rpm and load and see if there's a correlation.
Or possibly it's just waste gate rattle.

Unless you've turned it off the cars have a 'fuel cut on decel'. But it does turn fuel back on somewhere around the 1,500 RPM range. If you have the tuning stuff you can search for what RPM it activates at.

[Dackelone]

Originally Posted by mackeroni

What fluid do you use in your diff? I am thinking RL 75W110.

Castrol SAF-XJ SYNTRAX 75W-140


IF I lived in the states I think I would use a RedLine product. It's pretty hard to find their stuff over here in DE. The Castrol SAF-XJ SYNTRAX I can find everywhere over here. The SYNTRAX gear fluid is for M cars with a LSD... but it also works fine in our open style diffs.

Dackel