Originally Posted By: HangerHarley
I too have given this some thought, and i have to narrowly vote THIN.
Reasoning:
If Oil passages are sludged up, let us just say that they are.. a Thin oil SHOULD flow through it BETTER than a Thick one. HDEO T5 Rotella will then make it bigger and bigger, and look for Blackening of the Oil and change Filter and also Oil every 1000 miles if it is working. But Keep on putting Rotella T5 in; MMO if you must. SeaFoam? Maybe before the change. MAYBE.
If you use a Thicker oil, you are basically just thinking it will plunge itself out.
So, id narrowly say, "Thin."
Rotella T5 is 15W-40 anyways, so its right in the middle of thin vs thick.
This is exactly what I was thinking, I guess I named the thread wrong. NEW NAME: Which is less likely to cause ill effects during sludge removal- thin or thick?
Both thin or thick oil will both clean properly and really all oils will clean an engine if maintained properly, while Pennzoil may or may not be a better cleaner than others is a discussion for another time. If you are trying to clean an engine don't think that PP and PU are the only cleaning oils out there; QS, Castrol, VV, etc. all have cleaning properties.
I for example am trying to get rid of some sludge at the moment and will be changing the oil this weekend and will be going with QSUD and a quart of MMO. I was going to try PP but the QS is on clearance for $1.30 a quart so I'd be dumb not to buy it...wow this got way off topic...