Changing to a Synthetic

[onestackdram]

Ok guys I have a question.



DONT START A WAR



I am just curious as what would be involved in changing to a synthetic engine oil? The truck is a '97 3500 with 148 k. I am just looking to change the engine for now, if I like the 'performance' of it I may consider the rest of the truck later.



TIA



Russell

 

[Gary - K7GLD]

It's pretty much recommended that you flush the engine before switching to a full synthetic - and be aware that many users (myself included!) have experienced significant seal and gasket leaks and seepage after switching from conventional oils to synthetics in older engines...



Good luck.

 

[Deezul1]

I switched about 25,000 ago and prolly should have flushed it first but didnt know about it then. I did develop a leak that I dont know where it was coming from other than low on the front but it quit by itself which is ok with me so now no leaks. I dont think it was the front seal as it was replaced after the switch to Amsoil.

 

[onestackdram]

Ok after you flush, do I need special filters? I do think I would probably go the by-pass route. But as I am sure you've all figured out I dont know much about this process. So any education is greatly welcomed. So my all my questions are:



1. ) What do I need to do to prepare the engine?



2. ) What kind of filter(s) do I need?



3. ) Where can I get the 'products'? (AGAIN NO WARS JUST INFO)



4. ) Pro's and Con's of doing this on a truck with 147K?



TIA



Russell

 

[lschultz]

If you do a search on here about syn. oil you will find lots of info on it. It has been talked,talked,talked about quite a bit. You will get many opinions. Just decide what you want to do cause its your money Some people like it and some don't-its your call. If the oil you have been using has got you that far why not keep using it?



Questions:

1-Use an engine flush. It not change filters more often because the syn. oil will clean the inside itself. What type of oil have you been using?

2-SDF 80 is the Amsoil filter or one of the good Fleetguards.

3-If you want to use Amsoil you can go to there site and order it or have somebody on here get it for you. Lot of fellows on here just sell it at there cost.

4-If you got that many miles on it with the oil you have been using why not continue with it?

 

[John Berger]

If/when you flush the engine make sure you use two cans of engine flush due to the oil capacity in our engines. Check with whatever manufacturer you choose to purchase oil from. I use Amsoil and if you do the same, you will need two cans of their engine flush.

 

[Sled Puller]

Amsoil is the only true synthetic I have had any exprience with, so this is not a blanket type deal.



If you have leaks, it will leak worse. Becuase it flows better. It does not cause leaks, however.



The only reason I would switch at 150,000, is that you plan on keeping it, need cold weather performance, BOMBing excessivley, or extend your drains.



Remember, Amsoil cannot replace lost metal, or lost gaskets.





Put a clean filter on, 2 cans of flush, 20 minutes at about 1100 rpm, high idle, don't drive it.

Drain it good and long, replace filter and oil, your're done.



If you are going to extend drains without a By-Pass, I highly recommend the Amsoil SDF 80. At the very least, a Fleetguard.



I don't know if a By-Pass will pay for itself with that many miles already, but clean oil is always a good thing.





I would take a sample before you switch. You may discover a minor head gasket leak, no sense in finding it after you switch, and have to throw out the good stuff.

 

[onestackdram]

Well thanks to those of you who replied, and by the small sampling I got of responses I would say it's safe to assume that it probably wouldnt do me any good to change at this point of the engines life. So thanks to everyone.



Russell

 

[15w40]

I have been following this thread with interest, especially the recommendations about flushing the engine.



I have always changed from dino oil to synthetic oil every fall and back to dino in the spring. I do this to get the benefit of the 5W weight for cold starting. I have never flushed the engine when making the switch. The synthetic oil (Delvac 1) claims it is compatible with conventional motor oil, and I assume the small amount of oil left after draining would not matter. Am I asking for trouble? If the synthetic oil has a better detergent package and cleans out residue left from the dino oil, wouldn’t the filter catch this stuff?



My change interval for the dino oil is every 5K miles and I change the synthetic at 10K mile intervals. When the temperature is -20F and no power available, the engine cranks REAL slow with dino oil.

 

[Sled Puller]

Dave,

You are safe.



The flush is for heavily crudded up engines, ie, worse case scenario.

Yes, the filter will pick it up, but it possibly could plug it, if it was really that bad, or plug oil galleys.



High quality petroleum oils, are probably not that big of a problem.



Switching twice a year, it would never have chance to build up, anyway.

At 150,000, it may have quite a bit of sludge/varnish.