hey to everyone.. just bought a Durango with 85K miles. 4.7L engine. my question is, can i switch to Mobil 1 at this kind of mileage?? With all this talk about Oil sludge, Id like to get some extra protection. Or am i going to get problems (leaks and such) from switching to synthetic oil at this mileage?

Thanx

 

You can switch to synthetic at any point. Just make sure the engine doesn't have any oil leaks already....paying $4+ for a quart of oil in a leaky engine can get expensive!

 

if your worried about oil sludge drop the pan.see if the pick up is starting to clog if not ur ok.at this mileage it will be starting to clog already

 

Hey, thanx for the replies. Quick question, how hard is it to remove the oil pan on the 4.7?? is there some sort of a How To anywhere I can look at??
Thanx again

 

you can also run a flush for 2 minutes if your worried about sludge. that's what I did prior to running mobil 1

rock

 

Using an engine oil "cleaner" such as Motor Flush (WalMart, auto parts stores) is a cheap and effective way to keep sludge from building up in any engine. I put in a quart minutes before changing oil (do not drive with the oil diluted) and let the extra detergent additives and kerosene type disolving agents work their magic. I let the engine idle and give it some gas (not over-rev) a few times during about 5 minutes. Dump it out with the old oil; fill with new and replace the filter.

Doing this every third or fourth oil change will keep an engine very clean internally if the oil is changed regularly. It may be unnecessay if you use good oil and change it and the filter every 3-5,000 miles. You get sludge primarily from leaving old oil in the engine too long.

If you have an older, abused engine with deposits behind the rings and in other places that are helping to form necessary seals, using a high detergent cleaner may reduce those deposits and actually increase oil consumption and wear. CB3

 

I would be very careful with those motor flushes, you will not get all of the solvent out by dropping the oil from the pan only once. There is a good amount of oil/solvent that will stay up in the lifter valley and a few other nooks and crannys that will mix with and dilute the fresh oil you put in. If you are going to use it I would buy a bunch of cheap oil and do at least one oil change after the flush (run it for 15 minutes or until the water temp has reached its peak and held there for about 5 minutes) drop the cheap oil and put in the good stuff. The flush is hard on seals and gaskets and if you have leaks they might get worse. A good quality motor oil has enough detergent in it to break up sludge, just use a good brand and change it when it starts to look dirty. I would stick a flashlight in the oil fill and look around the inside of the valve cover for signs of sludge, if you don't see any then I would not procede with the flush.

 

I mostly agree with the previous post.

Possible exception to the post is that the amount of oil-diluted additive left in the engine after a flush. It is minimal and will basically serve to boost additive properties of new oil. The dilution of the additive is about 5:1 considering a normal 5 qt oil capacity and the addition of one quart cleaner (192 ounces total). If 5% of that six quarts is left in the engine (generous, but 10 ounces), then when 5 new quarts (160 ounces) are added, the dilution comes up to 1/17th of the total volume.

The real point is, good oil changed at proper intervals should not produce much sludge even over time. Sludge is an indication of oil that has broken down and remained in the engine too long. CB3

 

I agree with the concern with the use of the flushes, regular use of synthetic oil, either Mobil 1 or Amsoil will prevent the need for such drastic measures...

 

got an update on the issue. I glanced under the car and saw that dropping the oil pan would not be as easy as i thought, so we took the car to a mechanic. I bought a bottle of oil flush and was going to drop it into the engine and then drop and wash the oil pan. Once we got to the shop, the mechanic took off the oil cap and looked inside. The inside of the cap and everything around the area was covered in sludgy/greasy sort of a mix. I assume this was the infamous oil sludge. The mechanic replied that it's too late for a flush.. His words were "I doubt if the oil was changed more than once in this engine" (which could be true since the air filter I took out of the car looked black from all the dirt)... He said that at this point the valves were covered in this crap and running Motor Flush through the engine would only dislodge it all and make it fall inside making things even worse. He mentioned that the only way out of the situation was to perform a bunch of frequent (1,000 mile) oil changes. That should clean the sludge out..
At this point I dont know what to do. I can follow his advise and change the oil every few weeks for a couple of months.. (Mobil 1, to clean better).. Or should I insist on him running the flush through the engine and then dropping the oil pan and changing the oil???We just bought the car and really want to keep it, but the money to have to get a new engine simply isnt there..... Man, Id love to be able to rip the head off the idiot who had this car before....
Any advice???
Thanks to everyone...