Facts : if you had a 1500 with 5.2 and 120k miles and some sludge internally (recently replaced cyl heads and saw sludge around rockers and lifters) . There are no oil leaks anywhere and has used about 1/2 quart of oil in 2500 miles. History not known - just bought used approximatley2500 miles ago. Please : no groaning (I know this has been discussed many times) but I am trying to get all your opinions in 1 thread (oh : and help myself also). Question is : what would you do on your next oil change?

 

flush the motor, and install what ever makes you sleep better at night.. i use dino oil ..

 

Synthetic doesn't really sludge. In fact it will do the opposite. It will flush away most of the sludge already built up inside an engine. Thats why you have the old tale of synthetics causing leaks. The leaks were already there, the sludge was just holding the oil in because the gaskets had already failed. I run nothing but synthetics. I have 1 vehicle with 64k that has had nothing but synthetics since 500 miles and another that was converted over at 81k when I bought it still having no troubles or leaks at 151k.

 

Put in the synthetic and run it for about 1,000 miles change it and marvel at how black the oil is. Now putnew synthetic oil back in it and put the miles on it. I would highly recommend 10w 40 (or 30 depending on where you liveMobile 1......, Royal Purple if you can afford it. I mean the stuff is great as I run it in my truck, jeep, daytona, motorcycle, lawnmower and all the other small engines that I own.

 

Just run Mobile 1 synthetic for upwards of 6k miles. The engine is apparently already well broke in. Syn causing leaks is an urban legend.

Theres no need to change oil after 1k miles unless its an actual new engine thats being broke in.

 

From my experience, switching over to synthetic oil on a vehicle that has over 50K will yield some very black oil after the first 1K. This of course is caused from the built up sludge in the engine from the mineral oil (conventional), that the synthetic oilcleans out.I personly change it because of all the sludge that gets cleaned out and blended into the new oil. I also prefer the oil to look like honey (as it should) and not like tar.

 

You could always run cheap dino oil with a quart of MMO for 1K and then switch to synthetic. That should be a little cheaper than cleaning it with syn.

 

Yah thats a good idea too, and I'm all about saving money.....

 

agreed, MMO is awesome stuff... stops noisey lifters too...