Consensus for cleaning up motor?

[THORROMIG]

Machinist friend of mine from work & I have been talking about the best way to clean motor besides going flush method using products that you idle so many minutes or drive so many miles. What mileage do use BITOGers believe would be sufficient to clean up any unknown motor prior ownership using conventional or synthetic in terms of how many miles between oil changes?

 

[Donald]

You would need to pull a valve cover to determine what is there. Gooey sludge or hard baked on sludge.

In reality I do not think you need to remove all the sludge assuming the engine is running ok currently. You just need to make sure the sludge buildup is on a downward trend.

Auto-Rx.

 

[TFB1]

Last engine I cleaned sludge(and I mean remove valve covers and actually check) was a 3.3L V6 Chevy, that was in 1986 or '87... Generally with regular oil changes and oil from this century, sludge is a non issue...

 

[BrocLuno]

Can you afford to put Pennzoil Ultra in there for 3K at a time? If so, it would prolly be your best bet... Run oversized filter to collect the garbage and maintain low back pressure

 

[gregk24]

Short OCI's with a Pennzoil product, preferably Pennzoil Platinum PurePlus or Pennzoil Ultra Platinum Plus. This will be a more gentle approach than using an engine flush product.

 

[KenO]

Originally Posted By: TFB1
Last engine I cleaned sludge(and I mean remove valve covers and actually check) was a 3.3L V6 Chevy, that was in 1986 or '87... Generally with regular oil changes and oil from this century, sludge is a non issue...



Not true at all. There are some motors that are simply known to sludge. Using conventional oils for extremely long drains (say, some dummy puts conventional in a BMW or Lexus or something that calls for syn on a 15-20k mile change interval, and goes that long on it a few times). Sludge absolutely happens. When I pulled the intake on my '97 Silverado to do intake gaskets there was an inch (or more) of sludge in the lifter valley. Enough so that before I put any go-fast parts in the motor it's going to be completely torn down, cleaned, and reassembled. My luck I'll put a nice cam or swap the heads on it and THEn it'll dislodge some sludge and plug the oil pump and starve it

 

[sw99]

This works for me - On any used car I purchase, I will immediately start with a full 5K run of 20-25% MMO in my oil. I repeat this every few oil changes and keep an eye on it. If you get warm summers, I try and add the MMO to a HDEO like Rotella 15w40 since it has more detergents and more robust additives.

 

[sw99]

Forgot to mention, I do on occasion run a full can of the Berryman's B12 chemtool in the engine at idle for 15 minutes or so my I have heard of folks doing harm with it since it's pretty harsh. I would never add to oil that had visible sludge though.

 

[fdcg27]

If real sludge actually exits, many members report good results with Kreen.
If only light deposits exist, then a few short runs with any oil should clean it up.
A lot will depend upon how the engine was used.
If it was run to full operating temperature on most starts, then any heavy build-up is unlikely, unless coolant leaked into the oil.
If the engine was light-footed around town on mostly short trips, then sludge is more likely.

 

[Panzerman]

Marvel Mystery oil with a diesel oil would be my suggestion. I have found MMO really doesn't seem to thin the oil like you would think it does and actually mixes well. I have used it with 5w30 and it made the engine much quieter. I think if I were going to clean a engine safely without concern, this is the best route.

 

[Panzerman]

B-12 Chemtool is some Bad A stuff. I cleaned carbs with it and I haven't seen a carbon or residue it doesn't remove. The stuff has melted plastic mixing ups, I was using to measure it out for two stroke use. I would only use it in gas and not all the time. You don't want to over do it with this stuff. Most powerful cleaner I ever saw.

 

[TFB1]

Originally Posted By: KenO
Originally Posted By: TFB1
Last engine I cleaned sludge(and I mean remove valve covers and actually check) was a 3.3L V6 Chevy, that was in 1986 or '87... Generally with regular oil changes and oil from this century, sludge is a non issue...



Not true at all. There are some motors that are simply known to sludge. Using conventional oils for extremely long drains (say, some dummy puts conventional in a BMW or Lexus or something that calls for syn on a 15-20k mile change interval, and goes that long on it a few times). Sludge absolutely happens. When I pulled the intake on my '97 Silverado to do intake gaskets there was an inch (or more) of sludge in the lifter valley. Enough so that before I put any go-fast parts in the motor it's going to be completely torn down, cleaned, and reassembled. My luck I'll put a nice cam or swap the heads on it and THEn it'll dislodge some sludge and plug the oil pump and starve it

And how much of a intake coolant leak did that Chevy have??? And also what oil OCI?? No small block Chevy should be a sludger, the V6 I had no doubt had been neglected... Since I've gone back to the Blue Oval none of my approx 25 Fords have had sludge problems(this includes several I resold), nada, zero, none...

I wouldn't have been surprised if there had been some sludge my F-150, as it likely had not seen a change in two or three years before I became owner(less than quart in pan), but inspection into the oil pan showed it was clean... Can't see anything through oil fill and PCV still functions as it should, I'm not touching the top end...

Also note I said regular intervals, prior to SL oils that was(or probably should have been) 3K mi for most of us...