What have you done with or to your M3 today?

[jvictormp]

Originally Posted by Reddevils7

jvictormp

What do you think is a good mileage to replace FI as preventative maintenance? MY10 at 29k miles currently. Do they degrade over time too or it's mostly buildup over x amount of miles? I'm doing spark plugs soon and this crossed my mind

That question hasn't got an answer yet.

That's because people weren't able to determine the root cause of the FI failure.

There is suspect of deposit buildup in the injector, yes. But a good cleanup once in a while would avoid that, right? But it doesn't. People had stuck injectors that were periodically cleaned.

There is also the suspect that the culprit is the strainer at the pump suction, that degrades and let the element go through the pump and reach the injector. The solution would be replacing the fuel pump set.

But all of that would be avoided with an inline 10-micron filter.

My injectors have been running for 5 years now, only 15,000 miles although.

Only using top tier gas.

I don't expect to replace them soon, although if they were cheaper I'd centainly do because it's not clear what causes the failure.

[Reddevils7]

Originally Posted by jvictormp

That question hasn't got an answer yet.

That's because people weren't able to determine the root cause of the FI failure.

There is suspect of deposit buildup in the injector, yes. But a good cleanup once in a while would avoid that, right? But it doesn't. People had stuck injectors that were periodically cleaned.

There is also the suspect that the culprit is the strainer at the pump suction, that degrades and let the element go through the pump and reach the injector. The solution would be replacing the fuel pump set.

But all of that would be avoided with an inline 10-micron filter.

My injectors have been running for 5 years now, only 15,000 miles although.

Only using top tier gas.

I don't expect to replace them soon, although if they were cheaper I'd centainly do because it's not clear what causes the failure.

I bought mine single owner at 18k miles. I only use top tier, Shell primarily, I'm hoping he did the same. Adding a filter would be a good idea with FI replacement while also considering doing the fuel pump at the same time

[panda-R]

Originally Posted by Reddevils7

What did you use to polish them? Since I went catless X pipe I've noticed a lot more buildup obviously

Steel wool #0000 is pretty non aggressive and can cut out some oxidation. I then used mother's mag and wheel polish on it too.

There's still some baked on carbon that I might try some acetone on to see if that will dissolve it. Good luck!