piston tops dirty with oil, should I worry?

Seaneezy

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Mar 12, 2018
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Pics attached. Car was misfiring due to oil on plugs from either leaking VCG or valve cover itself. Regardless, when I'm changing plugs I always like to use my endoscope to see the tops of the pistons to make sure they are healthy. This time they seemed a little more caked than before, should I worry?

P.S: this is as wide as the camera goes, it is at the entrance of the cylinder from the spark plug galleys
 

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fmorelli

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https://www.fcpeuro.com/products/bmw-fuel-injector-cleaner-82140428376

Here's what I'd do. Jack the passenger side of the car up so the cylinder head is level. Pull the plugs. Pour an ounce or so of this into each cylinder. Let it sit overnight. Next day, suck out what you can. Put the car back together (make sure the spark plug seating areas are perfectly clean). Fire it up and get ready for James Bond smoke screen. Car will stumble, keep revs up between 2-3k and bring the car up to operating temp. I might do this right before an oil change. This is what we did on the M54 motors that would get sticky rings, except we used ACDelco x66p which is NLA and $100/bottle on eBay. The BMW stuff is supposedly equivalent.

Filippo
 
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JimboFresh206

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I Also do something similar on m54s with stuck rings.

Same process but use Mopar combustion chamber cleaner. It's $10 at any Mopar dealer. $17 on Amazon.


It creates a foam, and really releases/softens the carbon.
 
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fmorelli

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I Also do something similar on m54s with stuck rings.
Same process but use Mopar combustion chamber cleaner. It's $10 at any Mopar dealer. $17 on Amazon.
Good to know. I've had a bunch of M54 cars. stuck rings were a pain in the butt. I also had plugged cold start passages in the head that could not be unclogged. Anyway good reference on the Mopar stuff. I've also used BG EPR with good results. BG makes legit products - when I worked at the shop I don't know how many 44k bong hits we did to cars, straightening out issues related to sludge, coking, oil build-up.

Filippo
 
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Seaneezy

Corporal
Mar 12, 2018
133
34
0
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e90 LCI 335i
https://www.fcpeuro.com/products/bmw-fuel-injector-cleaner-82140428376

Here's what I'd do. Jack the passenger side of the car up so the cylinder head is level. Pull the plugs. Pour an ounce or so of this into each cylinder. Let it sit overnight. Next day, suck out what you can. Put the car back together (make sure the spark plug seating areas are perfectly clean). Fire it up and get ready for James Bond smoke screen. Car will stumble, keep revs up between 2-3k and bring the car up to operating temp. I might do this right before an oil change. This is what we did on the M54 motors that would get sticky rings, except we used ACDelco x66p which is NLA and $100/bottle on eBay. The BMW stuff is supposedly equivalent.

Filippo
Awesome, thanks for the write up. I will be doing this process this weekend. You said I should do this before an oil change? What does the cleaner do to the oil? I ask because I just changed my oil last week
 

Torgus

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Nov 6, 2016
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- when I worked at the shop I don't know how many 44k bong hits we did to cars, straightening out issues related to sludge, coking, oil build-up.

Filippo

Tell me more about these bongs hits. I have a boat bong. But it does not help the engine no matter how many times I hit it.
 
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fmorelli

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lol ... well back in the day ... we used to pop a 44k bottle, stick a vacuum line in it, and stick the other end somewhere in the intake and suck the 44k in, rev the motor to suck in the 44k and keep running until emptied, and immediately shut the motor down ... let it sit for about an hour.

Filippo
 

Rob09msport

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Oct 28, 2017
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Awesome, thanks for the write up. I will be doing this process this weekend. You said I should do this before an oil change? What does the cleaner do to the oil? I ask because I just changed my oil last week
All the releases carbon falls into crank case and especially bad the worse the seal on rings is. Also solvents aren't great lubricants usually.
 

Jeffman

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Jan 7, 2017
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https://www.fcpeuro.com/products/bmw-fuel-injector-cleaner-82140428376

Here's what I'd do. Jack the passenger side of the car up so the cylinder head is level. Pull the plugs. Pour an ounce or so of this into each cylinder. Let it sit overnight. Next day, suck out what you can. Put the car back together (make sure the spark plug seating areas are perfectly clean). Fire it up and get ready for James Bond smoke screen. Car will stumble, keep revs up between 2-3k and bring the car up to operating temp. I might do this right before an oil change. This is what we did on the M54 motors that would get sticky rings, except we used ACDelco x66p which is NLA and $100/bottle on eBay. The BMW stuff is supposedly equivalent.

Filippo
I was looking for this fuel injector cleaner online at FCP and apparently it’s backordered. Hunting around on the Internet it looks like this stuff is mostly kerosene-type stuff (mixture of aromatics, etc., great for dissolving Carbon-based crud). Kerosene is very low octane rating (like 20) so you can’t leave it in there and start the engine which is why you need to suck it out of the cylinder with presumably any loosened crud.

Another interesting thing I found in connection with this fuel injector cleaner is this SIM procedure for cleaning fuel injectors and combustion chambers in the Mini N14 DI engine. See attached. I wonder if anyone has tried this on the N54 engine? I wonder if the special tools cited in the SIM would fit the N54? I suspect they would.
 

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