What is the best cleaning oil?

[nomochevys]

I am asking because I think I have a 4.3 v6 sludge issue.
I put moblie clean 5000 back in it. with a AC delco filter.

The truck has only been driven a few hundred miles since. I am goin to make a point to drive the truck. What are the best oils to clean out an engine>?

 

[dsmith41]

Pennzoil Ultimate is probably best but just about any good synthetic will clean. How bad is the sludge?

 

[EricF]

How about running a quart of MMO for a thousand miles and swap the filter out afterwards and keep going for the regular interval?

 

[Oregoonian]

Any of the Mobil 1 flavors...5w20 or 5w30...and a Purolator filter (PureOne or Classic) or the Ford recomended Motorcraft.
______________________________
03' Ford Focus (2.3L) / 92K
Mobil 1 5w20 EP / 10K +/-
Filter: Mobil 1EP

 

[PhoenixTL]

PP or PU have nice stoudt additive packages....better then M1 IMHO

 

[shpankey]

I'd vote for Pennzoil Ultra. Cleaning is really kind of its 'thang' and what they hang their hat on at the end of the day. You could up it even more by adding some MMO into the mix. Just be sure you change the filter on it.

 

[chubbs1]

What you have in it right now is a great cleaner. You could substitute 20% MMO in the crankcase next time for 3K. Run it on the Highway some and change the filter (use a cheaper one) every 1K. That should get you clean, after that either run the MotorCraft oil (Great) under your severe service schedule or Pennz.Ultra under the normal schedule in your manual. You should not have any problems after that. M1 is a very good cleaning oil too.

 

[Steve S]

How do you think you have sludge problem? Do you have an intake gasket coolant leak?

 

[OVERKILL]

Originally Posted By: shpankey
I'd vote for Pennzoil Ultra. Cleaning is really kind of its 'thang' and what they hang their hat on at the end of the day. You could up it even more by adding some MMO into the mix. Just be sure you change the filter on it.


I believe that it is definitely their ADVERTISED "thang", though I don't believe we've actually seen any results of it doing that posted on this site.

 

[daman]

I agree with OVERKILL no real experienced posts about it's cleaning performance with pics.

that said i do think it's a good oil that should do well and clean things up.

any good synthetic or HDEO will get the job done also MMO is a performer also,lots of good products out there to pic from.

 

[steveh]

I get a laugh out of how many people lately think that mobil clean will clean out an engine any better then any other dino!!!

 

[ernied]

how do you know it that it dosen't ?

 

[nitehawk55]

Have you had a lifter cover off ? , is it full of sludge ??
The 4.3 is a pretty tough engine (as is/was and Chevy small block )and generally no issues with sludge unless it's never had regular OCI's .

 

[SLCraig]

Just a personal thing, I would be tempted to use M1 high mileage formula.

 

[nomochevys]

Originally Posted By: nitehawk55
Have you had a lifter cover off ? , is it full of sludge ??
The 4.3 is a pretty tough engine (as is/was and Chevy small block )and generally no issues with sludge unless it's never had regular OCI's .


I have not had it off. The last oil change was an eye opener for me. The filter was full of sludge and when I pulled the drain plug the oil came out in clumps to some degree. The was because of neglect and the oil has only been changed two times in the last five years. It did have mobil 1 synthetic oil in it and has most of its life. Its a truck that gets used very little and is short tripped to death when it does. Just runs to the dump, home depot ect..

Believe it or not, the truck runs as good as new. It just does not get driven much. Its only used when really needed. I am hoping some very short oci will help clean out the engine but was not sure what was the best oil to do this. Or for that matter does the brand really make that much difference? We will likely put mobil clean 5000 back in it the next time and then maybe switch to another brand like motorcraft or pennzoil. Both of those seem to get good reviews on this board.

 

[nitehawk55]

OK , I understand your issue now , thanks for clearing that up . I have a 1997 C/K 1500 with the 4.3 and it lives an easy life as well as it only has about 100K miles on it , probably gets about 2-3K on it each year doing some farm stuff (we have 4 horses ) like picking up hay or towing eagons a short distance with some other odds N ends it gets used for but it does get out on the hwy some for a few good runs .

As some have suggested a few short term OCI's with possable filter changes would help . If you had clumping sludge come out the with the drain I would really be concerned about the pump sump screen getting clugged with that so be careful on using any aggressive cleaners as some are suggesting , go slow and easy .
Have you thought about dropping the oil pan and doing a good cleaning ? I don't think the 4.3 is not too hard and might be something to consider at some point .

 

[nomochevys]

Originally Posted By: nitehawk55
OK , I understand your issue now , thanks for clearing that up . I have a 1997 C/K 1500 with the 4.3 and it lives an easy life as well as it only has about 100K miles on it , probably gets about 2-3K on it each year doing some farm stuff (we have 4 horses ) like picking up hay or towing eagons a short distance with some other odds N ends it gets used for but it does get out on the hwy some for a few good runs .

As some have suggested a few short term OCI's with possable filter changes would help . If you had clumping sludge come out the with the drain I would really be concerned about the pump sump screen getting clugged with that so be careful on using any aggressive cleaners as some are suggesting , go slow and easy .
Have you thought about dropping the oil pan and doing a good cleaning ? I don't think the 4.3 is not too hard and might be something to consider at some point .


I have not considered that but thank you for the suggestion. Its all going to depend on the next oil change and how it looks. This is a 96 GMC sonoma by the way. Im going to cut the filter open again to see what it looks like. The truck is old and banged up pretty good but still runs great and is worth trying to save. Its perfect for what my folks use it for.

Even though it did not get driven many miles the lesson I learned was to change oil once a year no matter what. I take a big part of the blame here because I though it was probably ok to let it go plus it was an old truck so who cares right? Wrong. That was a mistake on my part plus I just flat out forgot and neglected it. This is so out of character for me. I have never in my life done anything like this. Im an oil change junky for the most part and the first time I pull a caper like this it comes back to bite me. I should have known I could not get away with this.

The 4.3 is a good tough engine from my understanding. Its outdated by a long shot now but pretty reliable. We have never abused it but we have used it. I hope it holds up down the road. I want to kick myself in the rear end for letting this happen. I have learned my lesson and I hope the oil Gods let me squeak by. Thank goodness it was not on a new 35K car.

 

[Art_Vandelay]

Originally Posted By: nomochevys
What are the best oils to clean out an engine>?


Use a heavy duty diesel motor oil that is also approved for gasoline engines. Something like Mobil Delvac 1 or the equivalent from another manufacturer is probably your best bet. You have a very specific need and an obvious desire to address it. I sincerely doubt any 'gasoline only' synthetic could out clean one of these oils.

Search Delvac 1 on here and spend a little time reading about it. I think the more you look into it the more you'll realize it's what you're looking for.

 

[nomochevys]

Originally Posted By: nitehawk55
OK , I understand your issue now , thanks for clearing that up . I have a 1997 C/K 1500 with the 4.3 and it lives an easy life as well as it only has about 100K miles on it , probably gets about 2-3K on it each year doing some farm stuff (we have 4 horses ) like picking up hay or towing eagons a short distance with some other odds N ends it gets used for but it does get out on the hwy some for a few good runs .

As some have suggested a few short term OCI's with possable filter changes would help . If you had clumping sludge come out the with the drain I would really be concerned about the pump sump screen getting clugged with that so be careful on using any aggressive cleaners as some are suggesting , go slow and easy .
Have you thought about dropping the oil pan and doing a good cleaning ? I don't think the 4.3 is not too hard and might be something to consider at some point .


This is a 1996 GMC sonama that lives a similar life. 2 or 3K per year at the most. It tows also from time to time. Its got the power but wont stop. the brakes are the weak point imo.

Its a small truck but does everything we need it to do. I so wish that gm and ford would not kill off these small trucks.

 

[ronrackley]

Originally Posted By: nomochevys


... The last oil change was an eye opener for me. The filter was full of sludge and when I pulled the drain plug the oil came out in clumps to some degree...



I had exactly this sort of thing going on with a 1999 Suburban 5.7L Vortec a few years ago. It turned out to be antifreeze leaking into the oil because of a bad intake manifold gasket. A valve lifter had started making noise before I found the oil to be a mess. A quart of Marvel Mystery Oil mixed with 4 quarts of Shell Rotella 30 weight [a diesel rated oil with high levels of detergent and dispersant that make it excellent for cleaning] quieted the lifter in the first few days. Then I replaced it with the same mixture after a week and ran it another 1000 miles or so for general cleaning. I used Rotella synthetic 5w40 after than and put something like another 50,000 miles on that truck, if I remember correctly, before trading it two or three years ago. As far as I know, that engine is still running for the new owner.

I don't know this particular engine very well, but I'd definitely look into the antifreeze-in-oil issue if it were mine.