GM Truck Club Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
148 Posts
Discussion Starter · #1 ·
hi all its time for my oil change and just by chance im just about to turn 24,000 miles on my 2006 GMC 1500 4.3..my ?? is i want to go to syn oil and i always here about leaks if you dont do it from new is it to late to change it to mobile 1 since it is still under warrenty for another year and 12,000 miles they should take care of the leaks right ????

Dan
 

·
Registered
Joined
·
5 Posts
I believe you should be fine, I would check with dealer first and be sure there is no warranty issues.

I do believe its best to change to synthetic early in motor life as older engines will have a certian amount of sludge buildup inside motor.

The superior wash or cleaning package that synthetic oil has can start to remove that buildup. Many times people that do have engine problems after changing to synthetic with older engines, this sludge gets into oil and onto bearing surfaces and then the engine seizes.

Thats why I would change early if possible, I have 80K on my truck engine and do not plan to change to synthetic oil as I change my oil at 5K intervals. No pressure to keep truck on road for extended periods and have extended oil change intervals.
 

·
Premium Member
Joined
·
4,886 Posts
This is a good point. I made the switch to synthetics only in the last couple of years and I wouldn't go back, unless I get a vehicle under warranty that explicitly stated that I have to use a conventional oil ... and I'd be surprised if they said that.

I've heard about leaks, but I can't find anything solid on it. If someone has something they can offer that's been verified, I'd like to see it. Otherwise, I'd be surprised if it really was occurring, no new engine should be leaking by switching to synthetic.

If you change it yourself, make certain that it says on the receipt that it's synthetic, so you can justify why you're not changing it as often, and do they same if you get it changed somewhere too.
 

·
Registered
Joined
·
60 Posts
I have beeen using syn. oil ever since I got my Sub in 2006. I don't know what the previous owner used, but it hasn't had any leaks with synthetic. It gets better mileage with synthetic. The engine doesn't rattle as much using syn.Synthetic stays cleaner a whole lot longer. I now change my oil after 5k miles, or 4 months(with gas prices, it's 4 months ). I used non synthetic once. I didn't tell the new guy at the counter I wanted syn. with my oil change. The engine was NOT happy. But, I now have a little over 226k on my 7.4 .

My Suburban is just like centerfold...Synthetic in the diffs, transmission, transfer case, and power steering pump reservoir.
 

·
Registered
Joined
·
270 Posts
I wouldnt rec. syn oil if your motor leaks or even burns oil til you get it fixed. I used to use mobil 1 til i found out about Amsiol . gotta say its about the best syn oil ive found truck gets better gas miles and runs alot smoother.
 

·
Registered
Joined
·
380 Posts
I went from regular oil, to synthetic, and back to regular oil and WOW. Synthetic oil rocks! The only reason I went back to using regular oil, is because Royal Purple is expensive every 6,000 miles in my truck (same engine as yours). Synthetic oil clearly beats regular oil, but there are two things to take note of with synthetic:
1) Expensive
2) Dealerships warranty may prohibit outside oil changes
 

·
Registered
Joined
·
82 Posts
i just recently changed my oil from whatever was in it to Amsoil at 19,000. i say whatever was in it cuz i bought the truck used with 18,000 on it all ready and i didn't do the previous oil changes. i then drove to vegas and back (aprox. 1400 miles round trip) and got at least 1 mile to the gallon extra on gas mileage. if i would have had the time before my trip i was going to change out the trans and diff to amsoil as well but wasnt able to before this trip. i am taking another trip to vegas in june so i am hoping to get them both changed out by then.
 

·
Registered
Joined
·
100 Posts
I have been running synthetic oil last 600+k miles and wouldn't do anything else. I have it in three cars, generator, lawn mower and also good on firearms with gas systems. Keeps them from having carbon build up in gas system.
I run mine 15K and change oil and filter. Filter is always clean on inside, drain plug has absolutely no build up or deposits.
 

·
Premium Member
Joined
·
4,886 Posts
I'm currently running synthetic on both of my vehicles and will check the performance on both of them later this summer. Seems to be working very well now.
 

·
Registered
Joined
·
561 Posts
as long as the motor is broke-in and you do not have any oil leaks. if you got oil leaks fix them first or you be refilling with oil alot to offset the leak....mike
 

·
Registered
Joined
·
100 Posts
also it must only be used in late model vehicles because the cork gaskets won't hold it. I just traded a 76 F250 and could not use it as Mobil 1 would go right through the gaskets. One day this week I am pulling the rear end cover, cleaning it out and going to Mobil 1 75W90 and can forget that for life of truck unless I lose a pinion seal.
I just had a 1970 International 140 tractor rebuilt and I asked for neoprene oil pan and valve cover gaskets be put on it and was told they were not available. My engine man told me he used Mobil 1 himself and that he had a gasket coating he could put on it that would seal it up. Don't know what he used.

It did the trick. I now have 42 hours on the engine. Oil is still clean and not using any.

FWIW I change oil and filter every 15,000 miles. I ceveloped a clubricant engineer contact at a major manufacturer and he told me he did this and tested sample every change and it was still good. My previous Honda had 194K when I sold it, was doing fine. Had 120 K on a Mazda same schedule.

I have never found ANY DEPOSITS on drain plug and inside of filters come out silver. My Honda 94 has 232k, the Durango 134K and I run 10w30 being in the South, we never zee 0F weather. It will go in the Silverado at 50K when the 5w30 Valvolene has 2000 miles on it.

I also use it in rifles with gas systems. Keeps them from carboning up as well. I understand the Army Marksmanship Unit has started issuing Mobil 1 to their rifle team shooters for the M16 gas systems and it is doing fine there and they carbon up no end unless you keep them clean. My M1 Garands have it in gas piston and they get black but no carbon build up at all. Wipes right off.

Since a number of new Chevy's come with Mobil 1, it stands to reason they checked it out thoroughly before that recommendation.
 

·
Registered
Joined
·
561 Posts
i used syn with cork gaskets without issues in my 1967 galaxie500 with a 428 built motor. i drove it for a yeard almost daily and never lost or used any oil......boy i miss that car.
 

·
Registered
Joined
·
100 Posts
I got the cork gasket info from the Ford Dealership and as the article stated it is so fine that it will go right through the cork.

With the change schedule I have been running last 20+ years I guess I will stay with 15,000 changes as I have had no problems.
 

·
Registered
Joined
·
1,667 Posts
I bought my 1998 Suburban 1/2 ton 2wd with 195,000 miles on it.I use Mobil I 5W30 since I got it; works fine.It got 21.3 mpg at 70 mph on a 3021 mile hy trip last month.
The syn oil probably helped a little with the mpg.I get 12-14mpg(typical mpg ) in pure city driving.
Charlie
 

·
Registered
Joined
·
1,667 Posts
Hummer- no the 5.7. The 21.3 really surprised me also. Around town I get 12-14 mpg driving very, very carefully. I also have a gadget-Scangauge- that gives a constant read out of mpg and it didn't lead me to think I would get 21.3 at 70 mph. This was the first long hy trip, so I didn't really know what I would get. In my around town runs when I would get on city interstate it looked like I would get about 20 mpg at 58-60 mph,so I should get 17 mpg at 70 mph. Well, it didn't turn out that way- 21.3 mpg at 70 mph on cruise control.

I didn't use the Scangauge for the 21.3 figure-that is an actual calculation with miles and gallons pumped in. It was 3021 miles 142 gallons(this is from memory,so I might be a gallon off).I do have the 3.42 rear end, but with the small tirwes wheels 235/75 15 I turn about the same 1750 RPMS at 60 mph that the current Suburbans with the 3.72 diffs turn since they have 265/70 16 tires.

Thanks,
Charlie
 
1 - 18 of 18 Posts
Top