My piston rings are almost definitely clogged up and I've heard you can pour diesel on the pistons and it will slowly dissolve all the dirt from the piston rings.

I thought I would give it a try. But is there a better way to do this? Some have even said they first spray a ton of rust remover around the piston and then leave some oil sitting on the piston.

Another thing is, the effect of such treatments are probably more substantial if I jog the motor. But how do I make sure the pistons are in their proper positions when I stop and put the engine back together? Or should I just leave the 1st cylinder in its TDC or something? Never jogged a motor before.

 

Nothing is going to "dissolve" dirt/rust, If there's dirt/rust in the cylinders a complete teardown and rebuild is the only way to go......

 

I am less intelligent now after reading this !

 

I've heard many reports of diesel dissolving clogged up piston rings but I really don't know, since I'm new to engines.

 

Define "clogged up" piston rings & explain how you know they are clogged up.If you have a lot of rust or carbon build up,disolving all that crud is only get into the engine to circulate it throughout eating up rings,bearings,& all other moving parts,if not stopping up the oil passages & bringing your motor to early death.As stated above,a teardown is the only way to remedy your problem.

 

The rings are a moving part and because they rely on a delicate balance of friction against the cylinder wall and flexation in the ring groove to function correctly, once they have stopped functioning(generally due to varnish deposits filling the space around them in the grooves) they will not likely return to correct function through any chemical treatment. If they have lost only partial function, a treatment like BG Engine Flush and Compression Restore can help some, but it's at best a bandaid and will last about as long, if it gives any improvement at all.

The only way I know to restore ring function with any lasting effect is to replace the rings with new, restore cross hatch to the cylinder walls with a ball hone, and either meticulously clean the ring grooves or better yet, replace the pistons. Since ring gap and piston to cylinder wall clearance are important to ring seal, it's also worthwhile to be sure that the cylinder bores aren't excessively worn. If they are(you can quickly tell by how much ring ridge has developed at the top of the cylinder and also clearance between the cylinder wall and a new piston), you will want to tear the motor down and have the cylinders bored oversize to fit oversize pistons and rings. While you're at it, may as well rebuild the engine.

 

I've soaked bare pistons in diesel fuel for weeks thinking it would soften the old oil varnish in the ring grooves, and it did absolutely nothing, so I'd have to say there's no way it would do anything for you in an assembled engine.

 

my brother-in-law got some stuck rings freed up by filling his motor with tranny fluid. he let sit for a week, but everyday he would move the motor just a little. it actually ran great when he got done.

personally, i'd rather disassemble the motor and go through it.

 

jogging a motor ? Do you need a leash for it Popeye

 

I'd like to add that I won't be able to take the engine apart until next winter so that's not an option right now.
I know I should replace the pistons but I simply can't because of numerous reasons. Basically it's either running with carbon filled piston rings for another year or at least trying to dissolve them.

Right now I got some diesel sitting on the pistons but since it's a V-engine, the pistons are in a 45 degree angle and the diesel is only hitting the lower part of the pistons or draining on the floor.
Interestingly I noticed that some cylinders gulped the diesel down faster than others.

 

Are you burning oil or something? Is that why you are saying they're clogged up? I'm with everyone else, if you have any issues like that, you're going to have to tear it down. You aren't going to get much in the way of results with anything else. If you have diesel leaking down, you have it leaking around the rings, which is going to result in blowby while driving. You can't fix things that are just plain worn out.

 

Yeah. I used to be 100% sure it was a valve problem but apparently it wasn't, so now I've run out of time to do an engine teardown. The car is in a small rental garage and I only have time to put everything back together, drive the car outta there and that's pretty much it. Not to mention the space, I have like 10 inches of workroom.