I just took the pistons out of my V6 and they are pretty carboned up. Any suggestions for cleaning the gunk off.
Thx

What I found worked well on my '85 was to soak the carbon areas with WD-40 then let it sit for a day or two in an unheated area (mine was in the truck outside). After a little damp air hits the carbon, it just bubbles up like paint with paint stripper. A wire brush then takes it right off. Found that by accident, as I had soaked the piston tops with WD-40 to keep down any rust as I worked on the engine. Once morning, saw the carbon all bubbled up, pistons cleaned up pretty well:



Otherwise, something like gun cleaning solvent should do the trick (designed to remove carbon deposits).

Carb cleaner works pretty good. They sell it by the gallon. Put it in a container and let it sit overnight.

It's a little late in your case, but a fine mist of water sprayed into the air intake of a warm running engine makes the carbon break up into little pieces and simply go away.

This engine was making a loud ticking noise like injector noise but more. I was told by the dealer (henniger toyota) that I had a collapsed piston. I decided to tear it apart and have a look for myself. The piston skirts were not collapsed, the cylinders still had hone marks with a very slight ridge and the bottom end connecting rod bearings were still good. There is a lot of carbon gunk above the last ring and there was a lot of carbon on the top of the cylinder. I figure my engine noise is the carbon on the piston sliding tight on the carbon at the top of the cylider barrel.

>>>*That could well be exactly what the cause of the noise was, we are seeing the obvious marks in carbon buildup on the piston heads as these engines come in with higher mileage.

Cleaning the piston heads is pretty easy, I also use the WD-40 trick and then buff them with a soft wire wheel on our bench grinder. A putty knife with a very stiff blade works well too if using a little care.

The tough part is getting the ring grooves clean, they must be spotless to avoid jamming or sticking a ring. A hand held ring groove cleaner is handy, but again, great care must be used to be sure none of the aluminum material is removed. If any is, then ring life can be very short.

One point very often overlooked when inspecting the pistons is the vertical clearence at the ring lands. That is a wear point when the engine is in operation, if wear causes an increase in the piston ring side clearence, then the rings will "work" in operation and become barrel faced very quickly.

Oil consumption is then the result and spoils the job. Installing new rings is roughly a 10 minute job, it is the many hours just getting to them that is a PIA on this engine design....*EB

I cleaned the ring groves with a piece of old ring and the groves seemed to clean up fine. I did not take any aluminum out on the width of the groves but I did scrap the back side of the groves here and there. I hope that's OK.


Thx

>>>*Sure, that area is actually pretty strong. I end up with bright spots myself if I try to use a piece of a ring, the trick is to use the inside edge at the gap and draw it towards you rather than push it away. The carbon breaks up and falls out normally. Wear gloves of course or keep bandaids handy....

I have had some that were pretty gummed up, if real bad I stick them in a blaster using walnut shell as a medium, that makes short work of the job.

I tried sand blasting a couple of times years ago and learned my lesson there...*LOL**...*EB

just dont put a lot of water in.. you could risk hydrostatically locking the motor.. and thats a big nono! lol...

Do NOT use oven cleaner. It is a caustic soda mixture (lye) and it will eat the aluminum. Avoid strong acids and bases (caustic) for cleaning purposes. Solvents are fine. Cleaners are not....Take a piece of aluminum and put in some drain cleaner. The drain cleaner is either an acid or a base. Watch what happens....