[Ke90]

Here are some pictures of my piston heads after changing out spark plugs.

2017 M240i manual
9k miles
Gas: 93 + Boostane (approximately 98-99)

[ManiN54]

Why does it look like the pistons are melting? Is it just an illusion?

[B58_M240]

What mods and JB4 MAP are you running?

[Ke90]

Originally Posted by B58_M240

What mods and JB4 MAP are you running?

Those are old pictures, I will be updating them hopefully soon.

At the time:
1. VRSF cahtless downnpipe
2. BMS Intake
3. BMS Oil CC
2. MHD w/ BEF
3. Map 2-3
4. 91 Octane + Boostane


Now mods are same except I run full E85 with a Dorch stage 2 HPFP. I run map 3-4 now daily.

I am curious to see how they look after I ran some cleaners through and been doing straight E85. I do need to eventually take cylinder head off and get to those pistons but for now it has been running well, w/ little to no timing drops.

[Vorsprung_CJB]

The plugs look like pretty typical gunk buildup for full time octane booster usage. Never seen pistons that ugly though, how much of that crap are you running? Again its not really meant for full time use.

[Ke90]

Originally Posted by Vorsprung_CJB

The plugs look like pretty typical gunk buildup for full time octane booster usage. Never seen pistons that ugly though, how much of that crap are you running? Again its not really meant for full time use.

I was filling up every tank with it. I did about 6 tanks before I stopped. I was not aware not to be used full time, lesson learned.

As for the piston heads, I will hopefully get some more pictures this weekend with the oil change. I have been told pistons are not that bad, looks like I was running lean. However, I have not had any issues with timing on E85 I am curious to see if any of the cleaners helped. We will see

But thanks for the input.

[Ripper61]

Yeah, I used that on my 535i a while back...never again.

[Ke90]

More pictures after fuel cleaner and running full E85 now.



Just cylinders 2 and 3.