GM Truck Club Forum banner

1 - 20 of 27 Posts

·
Registered
Joined
·
655 Posts
Discussion Starter #1
I have a 2012 Silverado 5.3l engine with 70,000 miles on the clock. I’m the original owner and always have used Exxon/Mobil or BP gas. Early on I was using Chevron but the gas station switched to Exxon. Lately, mostly Mobil gas. I’m retired so the truck will sit days at a time. The engine runs beautiful and no problems. Lately, I notice at idle an occasional roughness, like a wiggle for a second. No codes and no other problems. AFM has not been touched. I’m suspecting the injectors probably need cleaning. Two months ago I put a bottle Techtron injector cleaner but can’t really say it did anything.

Is it worth going to the dealer for a fuel injector cleaning or just stick with a cleaner you put in the gas tank?
 

·
Registered
Joined
·
2,808 Posts
Okay Worth, ... your in a very warm climate. Next if you use "any amount" of ethanol fuel in your gas purchase, you might have those issues.

Another misnomer, as for fuel brands, it isn't the fuel brand the gives the best fuel, it is the proper "bouquet fuel" delivered for that particular region of Orlando and central Florida use.

Little side note: The fact is there are over 40 plus "bouquet fuels" used in the United States depending on locale.

Corporate gas company purchasers buy only the appropriate fuels for that region from 1 of the 4 national refineries. Only option they have is "with" or "without" ethanol and where is being shipped. With ethanol added, that reduces their cost per barrel and your performance at the pump.
You pay basically for what you get. Cheap prices, cheap fuels. Expensive prices, ... expensive fuels.

So your "primary objective" is to find fuels that are ethanol free, ...like Shell. Also it should be noted again, any amount of ethanol is actually a very corrosive cleaning agent in larger quantities. Adding fuel infector cleaner with ethanol based fuels is a waste of time, intelligence and money if you understand the chemistry of this type fuel.

If you let any vehicle fuel (ethanol included) sit too long, yes the fuel will varnish up the injectors, or any other carbureted motor that is why you should use "Stabil" fuel additive if that's going to happen.

Buy 2 or 3 tanks of non ethanol expensive fuel and see if anything improves.
 

·
Registered
Joined
·
655 Posts
Discussion Starter #3
There is Shell gas about 4 miles away. Every pump I’ve used it always reads not more than 10% ethanol. About two years ago WAWA came into town and they do offer ethanol free gas at some stations but doesn’t mention any nearby on the Gas Buddy web site or on the Wawa web site.

At the Shell website there is no mention of ethanol free gas but does promote their nitrogen enriched gas for cleaning and gunk prevention.

Gas Buddy reports for a nearby Shell Circle K; reg=$2.64, mid=$3.01, Prem=$3.25.
Central Florida has about the lowest prices in the state. The amount of gas I use per month, about twenty gallons, is only about $10 a month more. No bad at all.

https://www.shell.us/motorist/shell-fuels.html
 

·
Registered
Joined
·
2,808 Posts
Before you add any Shell gas, hit that station when your on "Vapors". You fuel gauge needle should indicate right on the empty line when you have your next fill up. Then just use "regular" (lowest grade) only because you don't have crazy engine compression that requires higher octanes.

I'm one of the lucky ones who's scan tool can read the percentage of ethanol in the fuel. Just got done doing a driveability problem like yours and found 11.87% ethanol in the cheap fuel he buys. He went to full gas mixture and his problems went away.

Here in Michigan, were at $2.65 for the cheap gas. Shell is in the low to mid $3 range.

I'm in the same boat, retired and only drive 3700 miles per year.
 

·
Registered
Joined
·
555 Posts
Next if you use "any amount" of ethanol fuel in your gas purchase, you might have those issues.
That is not necessarily true. I have been using E85 (51-83% ethanol) in my 2015 Silverado 2500 and my 2017 Equinox for over two years exclusively because the price has been $.80 to $1 lower than regular. Ethanol actually is a very good fuel system and injector cleaner along with leaving far fewer carbon deposits from combustion. It is petroleum fuels that leaves varnish and such that nasties up fuel systems and injectors.

I have been using a minimum of E10 since the late 1970's. Higher blends for most of this century when they started becoming more available. E10, E15, E20, E30, E50, and E85. Have never had a fuel system issue from ethanol including over 250,000 miles on a Pontiac Catalina 400 that was built before ethanol even showed up as a retail motor fuel and it lived on E10 for all but the first few years of its life.

Now of course, vented fuel systems like generators, lawn mowers, other small gas engines will have an issue sometimes with ethanol if it sits in the tank for extended periods. And some of those engines do not use quality fuel system components common in automobiles. And 2 strokes do not do well on it. But there is not a vehicle that has been made since the early 1990's that has not been designed to run well with ethanol.

But all that being said, the best fuel system / injector cleaners on the market have high levels of Poly Ether Amine (PEA). PEA is one of the recognized best fuel system cleaner additives. If looking for a good cleaner, make sure that PEA is one of the chief ingredients. Most of the better products are quick to point out that they use PEA, so one doesn't have to dig around to find out if a cleaner has it.
 

·
Registered
Joined
·
655 Posts
Discussion Starter #7
Most of the time my truck runs fine, but every once in a while the engine wiggles a bit when idling and usually before reaching full temperature. I don’t see it as a problem but just suspicious that an injector(s) maybe starting to fowl.

I noticed a Wawa gas station near by me offers ethanol free fuel. I couldn’t get a clear look at the price as I drove by but it was about $.75 more than regular. The problem small engines had with ethanol was rubber like components broke down from the alcohol, 2 cycles engines in particular and ask any landscaper when ethanol started, many of there tools had to have the carburetor’s rebuilt.

When 10% ethanol became the standard or The Department of Energy mandate, it was to reduce the demand on fossil fuel supply. Brazil leads the word with sugar based ethanol to reduce its dependence imported fossil fuel. Interesting ethanol increases air pollution. A good article on Wiki; https://en.wikipedia.org/wiki/Ethanol
 

·
Registered
Joined
·
2,808 Posts
When using ethanol in 10% or more concentrations, it "DESTROYS" all neoprene material. Over time, it will break down the plastics in the fuel system by making them brittle. Stiffens up neoprene rubber fuel lines.

E-85 (or any other ethanol based fuel) never has the BTU performance compared to straight gasoline. It's great in very cold temps, … but when temps climb such as Arizona / Nevada 110F temps in summer or very high altitudes, E-85 or ethanol based fuels its worthless for starting and keeping the motor running smooth.

Part of the fuel performance structure that nobody ever seems to talk about is what is the specific gravity of the fuel used in relation to the current ambient temp, barometric pressure and compression ratio's the fuel has to ignite? This is where 99.999% of gearheads fail in this concept.

I had a diagnostic issue out west where a person constantly used E-85 fuels, got into altitudes (8700 feet) coming from a 110 degree temp at 2000 feet and couldn't keep the vehicle running. The diagnostic outcome was to add 1 gallon diesel fuel to 20 gallons of gas (20 to 1 diesel ratio) in order to change the "specific gravity" and "burn characteristics" to get the motor to fire properly. Doing that "lowers" the specific gravity so the fuel doesn't ignite prematurely. … simple physics!

Now for the statement: never had a fuel system issue from ethanol including over 250,000 miles on a Pontiac Catalina 400 that was built before ethanol even showed up as a retail motor fuel and it lived on E10 for all but the first few years of its life.

Any factory stock Pontiac Catalina runs on "carburetors", … they use " solid jet type metering" If they have a "Viton material system", they "might" be able to get away with 10% ethanol (nothing more over the short term). But if I examined that fuel system, some of the rubber hoses would be rock hard and the fuel pickup screen would crumble in my hands upon touch. Also I would find some form of a driveability problems not disclosed like harder than normal starting on very hot summer days in Iowa. Or "transitional" spark knock on rapid acceleration. Another benefit the mean altitude in Iowa is 340 feet, … not like the rest of the country.


Back in late January, 1981, doing 100% engine driveability diagnostics on the C3 and C4 (early TBI included) engine control systems with "electronic carburetors" for GM, I was the one who started the "contaminated fuel issues" with gasoline manufactures adding chemical crap to their fuels. That was a time when vehicle manufactures were using "neoprene" accelerator pumps and diaphragms. Demonstrated in front of chief engineers, GM Legal, material engineers that putting in new neoprene accelerator pumps in Dualjets and Quadrajets carburetors that within 20 minutes those pump seals would expand to a point the accelerator pump would be stuck down in it's bore. Also during that time GM had a strong failure rate of brake boosters failing. GM eventually installed a inline booster hose filter to correct that problem too.

When fuel samples were sent out, 100% of the time ethanol was above 15%. Also found numerous other combustibles that were in the fuels. I was baited by the President of Marathon Oil (around 1983) when he brought in his Firebird for diagnostics, … claiming GM was making crappy vehicles because we were changing his O2 sensors every 60 to 120 miles. Took a fuel sample, sent it out for spectra analysis, came back with 14% ethanol, 7% silicone (which caused the O2 sensor failures) 5% paint thinner, and a list of other combustible crap. Yes his car could barely run. Told him along with his lawyer that you make a very high quality fuel that is full of non gasoline chit. He followed through and eventually told me the distributors were adding other combustibles to make additional profit. Apologized for his accusations.

So when people make any form of a fuel claim, … I have to se it, … test it for myself ... and use it in said vehicle for me to be convinced.
 

·
Registered
Joined
·
555 Posts
When 10% ethanol became the standard or The Department of Energy mandate, it was to reduce the demand on fossil fuel supply.
Some truth to that. It was to offset the demand for petroleum fuel, but 10% is not a mandate.

The Renewable Fuels Standard only says that 13 Billion gallons of ethanol be used in the U.S. It can be used in blends from 10% up to 85%. The RFS does not restrict ethanol free fuel from being sold along side blended fuels. The 10% "mandate" is State driven, and then, only 7 States have a a 10% mandate actually on the books. LA, MO, MN, MT, OR, PA, and WA.

https://www.greencarreports.com/news/1099149_state-laws-on-ethanol-in-gasoline-only-seven-states-require-e10-blend
 

·
Registered
Joined
·
555 Posts
For me, E85 is a very cost effective alternative to regular and especially premium.

It offers 100 Octane, which is a good thing for the 11.2:1 compression ratio of my Chevy Equinox 2.4 LEA motor. And no other fuel, including diesel version of the Equinox, offers as low of fuel cost per mile that I enjoy with E85 currently.

And most E10 actually is no more than 8%. The State weights and measures folks along with the Federal Trade Commission have some pretty stiff fines for percentages above the label on the pump. to avoid the risk of incurring those fines, most E10 is blended lower than 10%. It is also why even E85 never has more than 83%. I don't do so now, but I have tanked a lot of fuel in the past and saw first hand how things are blended at the terminals. What may have happened with fuel blending early on when ethanol was introduced is not what has gone on for the last 20 years. The regulatory controls are much tighter than they were in the 80's.

Currently E85 is going for $1.72 a gallon. My 2017 Equinox averages about 22 MPG for all miles on the E85 (city, highway, rural, gravel roads, etc). That equates to about 7.8 cents a mile fuel cost.

At the current price of $2.52 in my area for regular, my Nox would have to average 32 MPG for all miles to just break even on the 7.8 cent a mile fuel cost. Will never happen.

And primarily due to the cost savings, all of my flex fuel vehicles have been on E85 exclusively for over 2 years, year round. A great value. Not every one will have the same pricing in their area, so it may not be a value to use. But it is in my area and I would be retarded not to take advantage of it. Been using various blends including E15, E20, E30, E50, and E85 for most of this century (we have several blender pumps in our area that have blend choices). Still waiting for those fuel system related problems to show up. Even the wife's 2006 Cadillac CTS, non flex fuel, has used E15 on many occasions and nary a problem. We are keeping the car because it has been great. Even my step daughter is enjoying the lower cost of E85 in her flex fuel 2015 Jeep Grand Cherokee. She smiles when she fills up and sees what regular is costing everyone else. She's been using E85 for most of the Jeep's life and nary a problem.

But I encourage folks to not use ethanol laced fuels. It keeps the price for E85 lower for me. Ethanol is priced according to the commodity market and I want to enjoy the lowest cost I can. So the folks that rag on ethanol, please keep your fervor going! Ethanol is a terrible fuel and the destruction of mankind! Shout it from the mountaintop!
 

·
Registered
Joined
·
2,808 Posts
Love your research!!! But one fuel related repair will wipe out the cost savings using ethanol along with reliability to advoid fuel system failures.

Where I live in the southeastern Michigan area, we have more operable / licensed vehicles than people living in the area. Our motor vehicle count is 2.5 licensed vehicles for every man, woman and child. I myself have three vehicles. Being we live a sea of motor vehicles with huge amount of miles driven per day, people have learned the hard way to stay away from this ethanol crap because of our huge fuel system repair bills.

In my 48 years, your the only person who swears by using E-85 and other blends. Good luck for you!!!

But the American track record dealing with drivability diagnostics, using any ethanol is pure azz chit!!! Saving 80 cents a gallon for not using gasoline there will be a price to be paid. I'm waiting when you have to replace a E-85 module for $600 (excluding labor) because the guts melted away or the fuel pump seized up from internal melt down. Seen too many system failures.

Another area that I never mention is the health concerns which the public doesn't know about. When I did "flex fuel" driveability in the mid to late 90's, people who came in contact with these fuels would just pass out 12 to 24 hours later without reason. Eventually it was determine that ethanol was absorbed into the skin and caused announced major fainting spells. I was one of those victims.

People in Michigan have learned the hard way.
 

·
Registered
Joined
·
555 Posts
Another area that I never mention is the health concerns which the public doesn't know about. When I did "flex fuel" driveability in the mid to late 90's, people who came in contact with these fuels would just pass out 12 to 24 hours later without reason. Eventually it was determine that ethanol was absorbed into the skin and caused announced major fainting spells. I was one of those victims.
Interesting. The alcohol in beer and mixed drinks is the same ethanol that is in motor fuel. Just that the ethanol targeted for fuel is "denatured" by mixing with petroleum additives to make it unsafe to drink. But the ethanol plants do sell consumable ethanol to alcohol beverage producers, pharmaceutical companies, etc.

So it does beg the question if ethanol was the culprit or the petroleum fuel it was blended in to. But I will make sure that I don't pour it on myself and risk any issues.

It is most likely that methanol was involved as opposed to ethanol. Methanol does cause some pretty nasty things to the body. Just a 1/3 of an oz of methanol will cause permanent blindness and 1 oz most often will cause coma or death. Compare that to a shot of Everclear (ethanol) mixed in a drink at the local bar.

And likewise, methanol can be very detrimental to the fuel system of a flex fuel vehicle compared to ethanol. The OEM's of even flex fuel vehicles make a point to tell consumers not to use methanol of any amount in their fuel systems.

Taking ethanol one step further in production and making Butanol has interesting possibilities as a motor fuel. Neither toxic or caustic like Methanol and can be transported thru pipelines just like gasoline as it is not hydroscopic like ethanol is. Now that would be a plus for everyone by keeping transport costs lower.

My area in college was more in math and geology, but even a high schooler should know the basic difference between ethanol and methanol. Maybe not, as the public school system today leaves a lot to be desired.
 

·
Registered
Joined
·
2,808 Posts
When the paramedics took me to the hospital they stated that I just collapsed for no reason, all bodily functions were not indicating heart attack, blood pressure, oxygen loss or sugar issues. When the doctors had the tox screen performed, they found high levels of "ethanol" (not methanol) in my blood stream. Needed to explain how that occurred. 6 hours later, had another collapsing episode. After that, I was removed from the fuel lab permanently.
 

·
Registered
Joined
·
555 Posts
Like I stated, the ethanol in motor fuel is the same ethanol that is in adult beverages. My suggestion is that you don't drink alcoholic beverages. While methanol, ethanol, butanol, etc are all alcohols, they are not the same thing and have vastly different characteristics. There are those who do have reactions t0 ethanol. They don't drink hard beverages because of it. Seems like you were one of them. But given that the alcohol beverage industry is going gang busters, the majority of folks do not have adverse reactions to the stuff, that is, unless they binge drink at a frat party. Ethanol is also biodegradable and not a hazard to the water supply or any other human interaction unlike petroleum fuels.

So to blanket make assertions that ethanol in motor fuel will cause all these nasty things you say is not in keeping with the realities. It smacks more of an agenda against a motor fuel as opposed to sound inquiry. I, and millions of other folks have been around ethanol fuels for decades with no problem. It is going to take a whale of a load of solid evidence, not of the anecdotal variety, to make your case.

If I was the medical individual that checked you out and you had blood alcohol level that was of concern, I would have concluded you were a drunk that couldn't control yourself on the job.
 

·
Registered
Joined
·
2,808 Posts
I'm a recovering alcoholic, at that time I had a super high tolerance to alcohol, … and had been sober for a few years.
My booze habit for over 20 years was 70 to $90 a week minimum.

I went by what the doctors found in my system. They did test my external body absorption rate for substances like that and positively identified the source. Since that time through improved handling, I have had zero instances since then.

Going back to the earlier ethanol issues, I found an old TSB's on intake gasket deterioration with the issue of ethanol. Those seals are silicone base and still get destroyed by ethanol to generate a TSB. GM even had to change the old orange Viton composition to green.

Engine - Rough Idle/Misfire/MIL ON/DTC P0300
Bulletin No.: 05-06-04-029A
Date: June 24, 2005

Subject: Flexible Fuel (RPO L59) Rough Idle, Misfire, MIL DTC P0300
(Install Intake Manifold Gaskets With Teal Green Gasket Material)

Models:
2002-2004 Chevrolet Silverado, Suburban, Tahoe
2002-2004 GMC Sierra, Yukon, Yukon XL
with 5.3L Engine and Flexible Fuel (VIN Z - RPO L59)

This bulletin may apply to the following engines using regular fuel: 4.8L, 5.3L, 6.0L (VINs V, T, P, U, N - RPOs LR4, LM7, LM4, LQ4, LQ9).

Supersede: This bulletin is being revised to add additional diagnostic information.
Please discard Corporate Bulletin Number 05-06-04-029 (Section 06 - Engine/Propulsion System).

Important
: Always begin your diagnosis with the Diagnostic System Check - Engine Controls (SI Document ID # 1289827) for any MIL or driveability concern. The Diagnostic System Check directs you to the next logical step in your diagnosis. Follow the instructions in this bulletin should the rough idle, misfire, or DTC P0300 diagnostic procedure point to an air leak in the intake manifold gasket. Following the published diagnostic procedures will improve diagnostic accuracy and support our fix it right the first time approach.

Condition: Some customers may comment that the vehicle may have a rough idle, misfires and/or a MIL illuminated with a stored DTC P0300.

Cause: The L59 engine is calibrated for ethanol fuel (E85). Due to the low volatility of ethanol, the PCM provides higher fuel flow through the injector, which may pool on the upper manifold to head gasket material. Overtime (usually 12 months and longer), the gasket material may degrade resulting in an unmetered air leak.

Correction: Replace the upper intake manifold gaskets with the teal green gasket material, P/N 89017589.
Important : Do not replace the upper intake manifold gaskets with the original orange gasket material, P/N 17113557.

Inspect Intake Manifold to Cylinder head Deck for Warpage.
 

·
Registered
Joined
·
555 Posts
Can't speak to those specific vehicles, but my '98 2500 454 had not issues with ethanol fuels. Still ran good when I sold it in 2013. And neither did my ' 74 Pontiac, '76 Ford Mustang, '79 Ford Bronco, '90 Ford Bronco, etc. Not including all my parents and relatives vehicles over the last 50 years. We are farm oriented. When ethanol fuels became available, most of the family jumped on board. I know my dad had several Chevy and GMC pickups from the 70's on thru to around 2004. Swore by ethanol laced fuels. My folk's Suburban, they finally sold it after racking up almost 300,000 miles on it and it lived on ethanol laced fuels for its entire life. Guy in town bought it and kept driving it.

And Henry Ford developed his first autos to run on ethanol a century ago. The Model A was specifically designed to run on gasoline or high blends of ethanol, and had no problems doing that. Seems that the GM R&D folks stepped on their duffle bag on the L59 design. I know, it is tough to actually use the research of a competitor,, but a good engineer relies on the research of those who came before him.

But from that TSB you posted, it states that it "may" cause a problem. "Some customers may comment." And out of the whole stable of GM engines, only seems to affect the L59, and a limited number of them at that. And it was in the early days of retail E85 availability. There has not been any appreciable problems as we have gone on thru time with E85 availability. And in three vehicles I have owned with Flex Fuel capability, never a fuel system or engine problem using E85.

That one TSB is hardly overwhelming scientific data to conclude that ethanol in motor fuels is a problem of the nature you are asserting. Seems to be more of a design issue on the vehicles for those two years and specific engines the TSB addresses. And when taken in perspective of the 50 years that ethanol fuels have been available at the retail level and used, it is barely a blip on the radar.

I still sense an agenda and not solid reasoning in your assertions. It seems akin to the 1% risk fallacy that so pervades government thought nowadays.
 

·
Registered
Joined
·
555 Posts
Also this little snippet of a 2000 Tahoe 5.7 over 100K miles on E85 and the fuels system and engine tore down.....

 

·
Registered
Joined
·
2,808 Posts
Well Cowpie work, … eat, ... sleep, and breath motor vehicles in the Motor City and tell that to the people here about how great ethanol fuels from the Iowa farmland are being used successfully. They will laugh your azz off back to the farm country.

Being directly in the middle of GM driveability diagnostics since the early 70's forward, … dealing with all this fuel quality / performance crap problems, ... seeing what it does to internal plastic, silicone and neoprene materials then dealing with the "lack of performance" (BTU Output) per gram of fuel I will never approve the use of ethanol ever.

As stated in post #8, I was the one who caused the ruckus on fuel quality in January 1981. Management told me I was gonna loose my job for outrageous accusations. Once the various testing labs (multiple) got involved, they found over 90% gas stations tested in the Midwest had incorrect levels of ethanol or other non EPA approved combustible chemicals. Made the front pages of both of our Detroit newspapers for weeks.
State of Michigan Agricultural Department got it's azz reamed for not verifying contents within gasoline. Manufactures got their azz reamed for lack of quality controls from the EPA, it was a nuclear explosion that everybody got caught up in. Caused huge amounts of unrepairable driveability issues because a foreign combustible substance was introduced into the fuel tank which constantly trashed out non metallic parts.

I wish you were in the mix of things replacing these parts every couple of days with no fix in sight. Over the decades it's gotten better, but still see the root cause of the fuel system / intake manifold problems being present in 2019.

Everybody that comes over with a "flex fuel" type vehicle I measure their ethanol rate (have a scan tool that measures ethanol percentages in fuels that goes through the fuel lines). I also do specific gravity and fuel separation tests to see what is in their gasoline purchases. It's amazing 38 years later the chit you see in gasoline blends. Haven't found a gas station that sells less than 12% ethanol. Seen sometimes high as 15 to 16%.

The public who are smart or gotten burned financially , avoid using ethanol especially after a fuel pump replacement or intake gasket failures costing them $750 to $1,500 in unscheduled repairs.
 
1 - 20 of 27 Posts
Top