Changing to Synthetic Engine oil

Yes, you should always change the oil filter when you change oil, even if you're putting the same type of oil back in (new oil that is). I think it would be safe, even to your advantage to use synthetic oil until the truck is older and is pretty worn out. Then I would go with a synthetic blend so you don't suffer from unnecessay leaks. By older I mean 90,000 to 100,000 miles or more. Good luck.

Yes you should always change the oil filter when you change the oil. No matter if it is synthetic or not. Now also don't think that since you are switching over to synthetic that you can go 20,000km's between oil changes. I would still keep up your regular intervals of 8,000km's on the oil (or there around).

Synthetic oil does NOT mean that you can go millions of km's between oil changes, it simply does a much better job of cleaning, lubrucating and cooling a motor.
Switching too it is a VERY good idea and investment in the life and running of your engine. Paying a bit more for oil changes will pay for itself in the long run.

Good move, just keep changing that oil/ and filter together. I was once told some wise words by an old mechanic."Do you put the same underwear on after a shower?". Probably not

Cosmo. Mazda TEch

Cosmo,
If your desparate you can always go inside out :lol:

They are right on the filter as well as changing it at the same intervals or so. The filter won't hold up.

Inside out then rotate to the back LOL!

:mrgreen:

And that's a cringing Mr. Green

That might be true, but then GM says that their plugs are good for 160,000 km's. In my experience, when they are in that long they are not only seized, but they take out the threads. So what they say you can do and what you should probably do are two different things.

I look at synthetic as a way to extend your engine life NOT you oil change intervals.

I have still never heard of an engine blowing up because the oil was changed too much :roll: :lol:

You said a mouthful Cosmo, The maintenance intervals the manufacturers recommend drive me crazy :evil:

I preach maintenance to my customers and often falls on deaf ears. But when there is a problem that could have been avoided by maintenance, we become the "grease monkeys" :roll:

I used to follow the same pattern as heavyduty says for the first 60,000 miles of mine, but I switched back to regular oil. Not only is the 3000 mile interval good on the filter, but if there are grease fittings there they need to get hit.

Stick with the 5 20 synthetic. in my opinion long mileage oil. Here is a guide to help walk you through the steps of changing it.

https://www.2carpros.com/articles/how-to-change-engine-oil-and-filter

Please let us know if you need anything else to get the problem fixed.

If you have 400,000 miles on any engine without any major engine component replacement you are doing good.
The internal engine components do wear (rings, valve seals etc.) And what your describing is normal having so many miles as long as it doesn't show oil burning out the tailpipe.
If the valve cover gaskets are leaking you should look to replace them it creates a mess on the engine from oil build up and does stink when the motor gets hot.
For the most part if it runs good just keep your eye on the oil level. This engine owes you nothing at this point.

Honestly, you don't need to use synthetic, but I do agree it is more stable. All of them are good.
Mobil 1 seems to be the most popular, but all of the others make one too. Just make sure you follow the manufacturer's recommendation for oil weight under the temperature conditions you will experience.

If you have other questions, let me know.

Joe