Neglected Prius - Kreen or not Kreen?

[CR94]

Originally Posted by pandus13
The Critic and CR94, can we have your input please? ....
Thanks for the vote of confidence, but I have zero personal experience with piston soaks in anything. My Prius consumes very little oil, so far, and I'm anxiously trying to learn how to keep it that way. Some of them turn into oil guzzlers early in life, even with conscientious maintenance, and some don't, even at much higher mileages.

 

[Donald]

How about things like gasoline or acetone or lacquer thinner? Do soaks with the oil pan drain plug pulled and the stuff goes onto drain pan.

 

[Mad_Hatter]

Originally Posted by Donald
How about things like gasoline or acetone or lacquer thinner? Do soaks with the oil pan drain plug pulled and the stuff goes onto drain pan.

I always change the oil immediately following a flush/soak, that frees me up to use more harsh solvents if needed.

Acetone works good as a carb/TB cleaner (goopy junk) but I'm not sure how well it'd work on the hard carbon deposits on piston tops but I guess it's worth a shot. Lacquer thinner will work, that's mineral spirits basically. I'm not sure about gas but old timers and truckers have used diesel oil or kerosene as a flush. I personally like MMO as it's a) relatively cheap and multi purpose, b) 30% mineral spirits and 60 % kerosene IIRC and c) it also has small amts of benzene's in ortho dichlorobenzene and para dichlorobenzene, which dissolve carbon. There's a thread in the addys sub forum where a user got great results (before/after pics) doing overnight soaks w/MMO.

Fwiw, per the MMO website MMO when used per the label in the crankcase (like a half qt) will drop the hot number by [5pts]. So the little that makes it past the rings from a soak I don't suspect would have a dramatic impact on total viscosity. But I still like to change the oil afterwards, so I do it at the end of the oci.

 

[wlai]

Wow, you guys are great with advice, thank you all! There are a lot to consider. I checked the dipstick today and the varnish spot is gone, fwiw. I think I'm going to keep an eye on things and just let this batch ride for a few more hundreds mile, and change oil/filter. I had already purchased the Kirkland 5W-30 since it was a good deal, but I take it that HM oils generally have more detergent in the mix? I may get some HM oil and use that instead of Kirkland/Costco for the next few 3000 OCI and see how it goes. What are the forum favorites HM oil, if there are any?

Having done the Seafoam thing without being properly informed I'm a bit gun shy now to do too much . Thanks again folks.

 

[Mad_Hatter]

Originally Posted by wlai
Wow, you guys are great with advice, thank you all! There are a lot to consider. I checked the dipstick today and the varnish spot is gone, fwiw. I think I'm going to keep an eye on things and just let this batch ride for a few more hundreds mile, and change oil/filter. I had already purchased the Kirkland 5W-30 since it was a good deal, but I take it that HM oils generally have more detergent in the mix? I may get some HM oil and use that instead of Kirkland/Costco for the next few 3000 OCI and see how it goes. What are the forum favorites HM oil, if there are any?

Having done the Seafoam thing without being properly informed I'm a bit gun shy now to do too much . Thanks again folks.

Better detergency, more dispersants to hold particles in suspension and I've found they tend to contain more antiwear additives. QS HiMi for example has nearly 200ppm of moly and something like 100ppm of boron.

As for brands, take your pick. Valvoline MaxLife and Mobil1 HiMi both seem to have a strong following and I've personally used QS HiMi, Havoline and ST with good results. You might also consider Pennzoil Yellow Bottle HiMi. PYB is known for being a good "cleaning" oil. As long as you go with one of the reputable brands, and I would include Warren made SuperTech in that, you can't go wrong.

 

[nthach]

Originally Posted by pandus13
The Critic and CR94, can we have your input please?

.

The Critic suggested Valvoline Premium Blue Restore in mine. I visited him a few weeks ago and we did just that.

Prii have a habit of burning oil - the rings don't get an opportunity to properly seat(and they are low-tension ones) as well as the duty cycle which creates an opportunity for oil to coke up in the ringlands. That's my hypothesis.