Mobil 1 brew.....

[mjk]

01 Tahoe with typical cold-weather piston slap.

Plenty of M1 on hand (AZ clearance oil).

What I am trying to accomplish - a long time member had very good luck with Mobil 1 Turbo Diesel Truck eliminating his piston slap. I'd like to make an attempt to replicate that formula using what I have. I am thinking 4 quarts of Mobil 1 0w30 and 2 quarts of 15-50.

Thoughts? It obviously isn't going to be exact, but will it be close?

thanks.

 

[fdcg27]

Where are you located?
You could have bought Mobil Delvac 1 5w40 for less dollars after MIR with store deals, but that's passed.
In a warmish winter area, you could use more of the 15W-50 and less of the 0W-30.
In a warm area, the 15W-50 by itself would be fine and if any grade of oil would quiet down the noise, a 15W-50 would.

 

[mjk]

Im in Minnesota. Truck is inside a garage, if it is under 20 at night.

Just looking to see what the mixture would end up being approximately. Simple divsion yields a 5/36 oil.

Also, this wasn't something I anticipated doing, else I would have picked up Mobil 1 Turbo Diesel Truck this fall. While in AZ, this thought just popped into my head.

 

[fdcg27]

Okay, so even worse than Wisconsin.
The mix you propose sounds good, especially since you garage the truck when moderately cold nights are expected.
Better not to mix, but you could certainly give it a try and see what happens.
Let us know whether this blend helps with the piston slap noise.

 

[tig1]

Even though piston slap is a nuisance, it doesn't shorten the engine life. My bro-in-law has a 02 Chev 5.3 and he claims Mobil 1 5w30 Extended Performance has helped his engine but not stopped PS.

 

[69GTX]

I'd be more inclined to first try that mix in a summer OCI where even if the mix came out at 10w to 15w then it would be much less an issue.

I thought the Mobil 1 0w30 was a magnesium oil like their 5w30. But every VOA I looked up over the past 8 years (except the link below) shows them to be a high calcium - no magnesium oil. So I'm confused on trying to keep up with Mobil 1 on which oils are magnesium and which ones aren't. Just when I think I have it right between Mobil 1 and Castrol magnesium oils, I find something else I misunderstood.

So mixing a no magnesium 50 grade with similar no magnesium oils is therefore less of an issue. If you were mixing the 5w30 I'd said don't do it. But "some" of their 0w30 grades, and all 40 grades could be fine to mix. Mobil 1 0w30 seems to have come in several flavors over the years, from AFE and ESP, to a full out racing oil with huge amounts of moly, phos, and zinc. Formulations could have changed back and forth. I'm guessing you have the AFE. The latest Mobil 1 Advanced Fuel Economy 0w30 VOA below from 2015 shows it to be high magnesium. Based on that I don't think it's optimum to mix it with 40/50 grades. You have 2 viscosity differences in play as well as the add package.

VOA Mobil 1 Advanced Fuel Economy 0w30

VOA Mobil 1 15w-50

 

[KCJeep]

I've never known of an oil that could stop piston slap. Lifter tick maybe... you sure on that?

Our old Lumina still was a faithful work horse we couldn't wear out, but the last few years the piston slap was so bad I could hear it in the house when my daughter started it in the driveway. No oil made any difference that I found.

 

[mjk]

I have no illusions that slap reduces the life of the 5.3. That has been proven over and over!

All this is, is a cheap experiment with $2.00/qt oil. Nothing ventured, nothing gained.


BTW, the 0-30 is the AFE variety...

Oh yeah, I should insert 'mask' the symptoms of slap, not eliminate the issue... obviously, it isn't going to eliminate a design flaw.

 

[69GTX]

Originally Posted By: mjk

BTW, the 0-30 is the AFE variety...


My VOA above for that is actually a used oil analysis, though close enough. The mix would come out to be approx 1530 Ca, 753 Phos, 902 Zinc, and 522 Mg.

 

[bluestream]

Originally Posted By: tig1
Even though piston slap is a nuisance, it doesn't shorten the engine life. My bro-in-law has a 02 Chev 5.3 and he claims Mobil 1 5w30 Extended Performance has helped his engine but not stopped PS.


Hes. right, its kinda normal for a lot of engines. Especially if its only cold piston slap.

 

[bluestream]

Here's what we did back in the 60's ...Piston Knurler for an old engine to get a few more year's out of her when there was slap.. Don't knurl too high, or you have to file the aluminium down.

 

[Ramblejam]

Originally Posted By: mjk
What I am trying to accomplish - a long time member had very good luck with Mobil 1 Turbo Diesel Truck eliminating his piston slap.


You should probably follow-up with Turk.

Regardless, if you want to eliminate slap, Kreen will do it. Here's a quote from a guy I was helping who has over 200k on his 5.3...
"Just a FYI since I've done this I haven't noticed the startup engine knock at all. Has knocked like a rod gonna fly out since 20,000 miles on startup."

GM released a TSB on these ages ago, and causation was plainly laid out (carbon).

If you want to just mess around with different oils/experiment, then do so. It won't stop the slapping, though.

 

[nascarnation]

I've run a mix of Mobil 1 15W50 and Castrol 0W30 (vintage 2003/4) in my Cadillac 3.6 for years. Not for any particular technical reason, just to use up inventory purchased at minimal cost.

I call it 7.5W40

Seems to work just fine.