To flush... or not to flush?

[acarpenter86]

That is legitimately my question. Haha.
I bought this car as a fixer upper and was able to repair damage done by accessory belt being eaten by main seal. But obviously I've got a bit of a sludge problem as well. While valve cover was off, I considered trying to clean this somehow, but I was concerned that large particles would fall deep into the engine. I've read of folks having great success with Liqui Moly's engine flush product, and I would like to try it. My thinking is that it would be more of a dissolving process on this gunk as opposed to me getting "pieces" of it everywhere. Just wanted to see if you guys have any advice one way or the other?

[acarpenter86]

Forgot the silly photo

[MarcoZandrini]

I’m against engine flushed. Why? Who knows what gunk will come loose. My preferred method is to change the oil and filter more frequently. Oils have additives that sloooowly clean the engine.

[acarpenter86]

I’m against engine flushed. Why? Who knows what gunk will come loose. My preferred method is to change the oil and filter more frequently. Oils have additives that sloooowly clean the engine.

After doing a lot of reading on flushes, I think you're onto something.
I already got fairly lucky not having to replace my engine, so since it is running fine I think I'll do as you say.

[Cobra1956]

For the sake of conversation what gunk? Where do you think it is located? Where do you think it goes? What is the benefit leaving it in the engine and to chance. A diagram of the oil system might come in handy.

[jclausen]

Granted there is some gunk but is not that bad, I would not flush it. Just start changing your oil. We are doing a valve cover gasket on an 2006 E90 325 with 234,000 who has done regular oil changes at 5k the inside of the engine looks great.

[Cobra1956]

Think this is the key," who has done regular oil changes at 5k the inside of the engine looks great."

He purchased a fixer upper.
Start with a paint brush and shop vac. Then some thing that will dissolve the crud like diesel fuel. Should be able to get the top nice and clean. Flush the pan out with more fuel without running the engine .Little assembly lube or similar up top before restart. Run some thinner oil and cleaning in there for a bit at idle. Flush load up with fresh oil and drive for about and oil change again

Or just bolt it back up and convince yourself you didn't really see it. This is not meant to be smart just could not do that myself once I have it open. It's more work that most think but can be done in an afternoon.
Regardless, best of luck and enjoy the project!

[acarpenter86]

Thank you both for the response. I think I will go with a 1000 mile oil change, followed by some 3000s and see if that helps. If not, I will do the method described by Cobra 1956. Yes, I should have done that when I had the valve cover off, but at that time I didn't even know if the engine was going to start, so did not want to spend hours tediously cleaning all this stuff off. May seem lazy, but it is what it is. But it came back to bite me, because now I'm kicking myself for not cleaning it!

At any rate, I have a couple of suspension noises I need to diagnose and want to just enjoy driving it for a while before tearing into anything again. I can't tell you how rewarding it was to start up the car after cleaning and calibrating the steering angle sensor and driving to work with no DSC/4X4 light on. Well, that and the 24 mpgs I'm getting while I have this insurance monitor in there. Helps my lead foot...