I have a 1999 Blazer (see my signature below) with 135k miles on the engine. I am planning to keep it for at least several more years, perhaps keeping up to 180k or 200k miles. I put about 7,500 miles on it per year and I tow a 2,200 lb boat/trailer a couple times a year across the widest part of Washington state.

Since I want to keep the truck I am considering switching to a synthetic motor oil to prolong its life as much as possible. I'm am very religious with the oil changes (per GM recommendations) using Wix filters and Gastrol GTX oil.

What would people recommend for my new oil? Anything specifically good for an older motor?

Is there any risk of the new oil removing sludge that will open up any new leaks?

Thanks,

Christine

P.S. I've address the leaky oil-line problem and will be installing the lower intake manifold gaskets in a week or so. I also recently had the transmission rebuilt with the front end components all replaced in the last couple years so I think it is worth keeping.

 

Changing to synthetic will not cause any leaks or anything of that nature.

I use Mobil 1 full synthetic and always have.
What others use, I am not too sure.

 

I have a 2003 Blazer 2 door with 4 WD and 104,800 miles. I have been using the Pennzoil Platinum full syn oil in 10w/30. I use a NAPA Gold filter=Wix. If your engine has sludge condition, you may see your oil get dark very quickly. That's the syn oil cleaning the engine of sludge! It is not a problem. If you see that happening, I would go to 3k Oil Change Interval/ OCI until the oil stays clean. Changing both oil and filter! Then go to a 5 k OCI. I don't believe in the extended intervals of 10, 15k or more.

 

Full synthetic from 100k on here!

 

I use Valvoline full syn "high mileage" 10-30 or 5-30 depending on the temps ahead.....

These synthectic oils are great..for lube....and the brown sludge that i drained after an intake gasket failure, still has NOT separated after a month like dino oil does.......

I think it may have kept any damage from happening .........??

 

I use good old dino 5W30/Wix oil filter and change it every 3000 miles. Synthetic certainly doesn't hurt, but for me the benefits (ever so slightly higher mileage and allowing extended oil change intervals) fail to outweigh the additional cost. If you don't go longer than 3000 miles, IMHO synthetic is a waste of money - an I refuse to go to longer oil change intervals. I'd rather have new oil.

 

DIY oil change and buy full syn oil at Walmart or your favorite auto parts store. Buy the Wix or NAPA Gold equivalent oil filter and know the oil and filter change is done correctly. The old oil is drained out completely, the new filter is 'partially filled' and the gasket is coated with oil. The filter mating surface is thoroughly cleaned. The inspection after the oil change to ensure there are no leaks and the oil level is correct. So by DIY , you save money and know it is done right. Now you don't feel you have to run the Oil Change Interval/OCI up to some extreme length such as 10 k miles to justify the extra expense. Did you change the oil drain plug gasket? The guys at the quick lube just crank down hard on the old gasket to 'make sure' it isn't going to leak! This may explain why there are so many stripped oil drains!

 

Jim,

Yes, I do all those things, except for partially filling the filter first; just to messy. However I do immediately check and top off the level after my first initial run of the engine. I even replace the gasket on the train plug.

I like doing these things myself. Even the workers at the dealer can have iffy-level skills. :-)