Oil Sludge vs Frequent Oil Changes

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On another forum I read about somebody losing a Chrysler 2.7 engine because the engine sludged up, the hydraulic timing chain tensioner did not work properly, the chain jumped and destroyed the engine. Considering all the problems oil sludging causes, why not avoid it with shorter oil change intervals? I used to go with 3k mi OCI, I now use 4k mi OCI (on dino oil). This is with 90% city driving. The OLM on the Sierra comes on about every 5k mi, so I am changing the oil a bit more frequently than the OLM recommends. I like to get the oil nice and hot before I change the oil and I let it drain for at least ten minutes. I have never had any oil sludge in any of my vehicles. I have never had to use AutoRx or any engine rinses. Seems to me the extra cost of more frequent oil changes is well worth it to avoid the sludge.
 
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Yes & No. While you have a good methodology, some engines like the 2.7 are sludge prone due to poor PCV/breathing design that causes the engine oil to be taxed to death in earlier models before it was corrected later on. You could safely follow the OLM with your dino oil and you would be fine as it is very reliable. \:\! I change my oil at 6K miles and I'm going to go even further because I use high quality syn oils and good filtration and monitor it all with a UOA to ensure I'm not over taxing the oil.
 
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 Originally Posted By: George7941
... Considering all the problems oil sludging causes, why not avoid it with shorter oil change intervals? I used to go with 3k mi OCI, I now use 4k mi OCI (on dino oil). This is with 90% city driving. The OLM on the Sierra comes on about every 5k mi, so I am changing the oil a bit more frequently than the OLM recommends. ...
You're changing at about 20% earlier than OLM, which is not too early with dino oil, specially since most of your trips are city driving. With syn blend you can safely change oil when OLM down to zero.
 

George7941

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The OLM accounts for city driving.The OLM intervals would be longer with more hwy driving. If I had an engine with known sludge problems, I would probably change the oil at 1/2 OLM intervals i.e. twice as frequently as the OLM wants me to. Who wants to deal with oil sludge and associated problems?
 
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use syn and run OLM to 0%. syn gives that cushion needed if your afraid of sludge with dino.
 

George7941

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Synthetics will give better protection against sludge formation from oil oxidation but they do nothing for sludge formation from PCV,condensation, small coolant or fuel leak issues. Frequent oil changes will help in these cases.
 
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