Locked in place piston rings

[tom/marshall]

I do a lot of mechanical work, for a DIY'er. In the last two engines that I've been into the oil scraper rings were locked in place by carbonized oil (one Dodge 3.9 liter six cylinder, and one 3 liter Mitsubishi, both more than ten years old, and both with near 200K miles). Wear was not bad in either engine, oil consumption was fairly high.

In both cases, oil was changed fairly regularly, at least as far as I know; they belong to family members. If these engines were oiled with synthetics, would the carbonization stop. also, what can, or should, be done to assure non recurrence of this with regular oils.

Thanks in advance for your thoughts.

T.

 

[Propflux01]

You may want to ask how often that they consider 'changed regularly', where it was changed, and what oil was used, if it was a regularly used brand, or whatever was the cheapest oil they could find. I do not think synthetics would really help unless thier 'regular' oil changes were in the neighbourhood of 10K miles.

 

[Ded Mazai]

There could be a number of reasons. The most probable is a worn ring groove. To much oil gets past the oil ring. Air/oil filtration is also important in the long run. Using a synthetic oil is probably an advantage in a few ways. They are less prone to nitration which contibutes to sludge. They contain less VI modifiers.
Very thin oil are especially bad when it comes to nitration. So the logic says to use a bit thicker oil with no VI improvers in an old engine. Single grade oils, for example. Or a synthetic oil (group 3 or 4).

 

[Pablo]

Do doubt synthetic oil would help.

Most importantly this is where AutoRx is absolutely the best. I really distrust AutoRx's ability to stop seal leaks, however when it comes to REALLY cleaning stuck rings I have seen nothing better.

Tom/Marshall - next time try the AutoRx. If this is the only issue with the engine you may save a bunch of time and money, and be amazed to boot!!!

 

[FoxFour]

A person that I know replaced the engine in his wife's Plymouth Voyager. When he completed the swap, he noticed that the engine would not turn over. My other friend suggested putting transmission fluid in each of the cylinder bores and let the fluid sit in there overnight. The thinner viscosity of the tranny fluid 'cut' through the carbon and unstuck the engine. They then proceeded to do a quick oil change after the engine was run. This is an old mechanic's trick but it was the first time that I did see this trick in action.

 

[JohnBrowning]

Remove the plugs and pour a couple 1/4 cup of B-12 Chemtool into each clinder. Let it soak for a few minutes. Then either hand crank the engien or crank it a few times with the starter. Make sure you un hook the coil wire from the coil. Let it set over night. The next day retreat the cylinder and again crank it over a few times. Put the pluges back in and start the vechile up. Bring it up to temp and drain the oil out and refill.

If the vechile is still haveing ring problems auto-rx is the next step.