Carbon removal & precautions

[V1]

When I replaced my spark plus last summer, I noticed a lot of carbon/soot on the pistons. I have an '04 Mazda 6, 3.0L, with 65,000 miles on it. Eventually, I'd like to clean that engine out. Perhaps by spraying some LC/FP down the vacuum, or just by a good Seafoam-ing.

I am concerned that any large chunks of carbon that become dislodged during that process could cause damage. Particularly to the cylinder walls and valve seats. What is the likelihood of that, and is it avoidable?

 

[surfstar]

Start using Lucas UCL or FP 60/3000 each tank - should slowly and safely clean it up.

Or for faster results - use a tank of techron/regane/redline fuel treatments, then follow up with UCL/FP.

 

[Quickbeam]

If it's a heavy an overnight piston soak followed by a short stint of water injection works well for me.

 

[ikeepmychevytoo]

Actually overnight piston soak was the only thing that worked for me. It was a big and only step. Then, I advanced the spark timing and engine run slightly hotter under load, this should have burned the rest. However I don't recommend this. I took my own risks and engine is now much peppier and easier on the gas.

 

[Drew99GT]

I've now done a full on Seafoaming in 3 different vehicles via spray bottle through the throttle with engine running. On my Corolla, it visibly removed carbon off the piston tops as seen through the spark plug holes. And it practically eliminated all ping on those 3 vehicles.

Carbon on valve seats will get broken up like a toothpick. Valve springs have hundreds of pounds of force. Any chunks will get blown right out the exhaust IMO. Stop worrying, JUST DO IT! Your car will likely run better and it's messin around with a car engine. What could be funner?

 

[V1]

Ok, "damage" was the wrong word - "wear" is more appropriate. I'm not worried about it, but I do want to clean things out as gradually as possible to avoid unnecessary wear.

I've been adding FP60 to every tank for the past 35,000 miles, yet I still have a nice layer of soot on the pistons. FP60 does not seem to be strong enough to do all that cleaning by itself.

Drew, do you use FP60?