Intake manifold off with pics of intake valves with deposits.

Stoddard · February 3, 2015

Hey guys, being a former tech, I have seen this a lot. Not only on the new gen 5 v8's but every direct injected gas engine out there. GM has a service bulitin for the customer to use better gas. I remember shell was on the list. They say lower grade fuels burn dirtier. Like I said this is a problem for every engine with di. All I'd say is get your intake cleaned at the dealership regularly or seafoam it. In extreme cases it causes misfires.

fondupot · February 5, 2015

Hey guys, being a former tech, I have seen this a lot. Not only on the new gen 5 v8's but every direct injected gas engine out there. GM has a service bulitin for the customer to use better gas. I remember shell was on the list. They say lower grade fuels burn dirtier. Like I said this is a problem for every engine with di. All I'd say is get your intake cleaned at the dealership regularly or seafoam it. In extreme cases it causes misfires.

Makes me wonder what kind of gas the OP was using. His info says he is from North Dakota. Nothing against ND, but its reasonable to assume hes using a smaller chain gas station that might not have the same quality of gas as a larger chain like Shell, BP or Mobile. Also what grade of gasoline was he using.

Either way this doesn't instill a lot of confidence in these motors. I am coming up on 15000 miles....might be looking into the BG top end service and adding a catch can.

Silverado-Hareek · February 5, 2015

Hey guys, being a former tech, I have seen this a lot. Not only on the new gen 5 v8's but every direct injected gas engine out there. GM has a service bulitin for the customer to use better gas. I remember shell was on the list. They say lower grade fuels burn dirtier. Like I said this is a problem for every engine with di. All I'd say is get your intake cleaned at the dealership regularly or seafoam it. In extreme cases it causes misfires.

Makes me wonder what kind of gas the OP was using. His info says he is from North Dakota. Nothing against ND, but its reasonable to assume hes using a smaller chain gas station that might not have the same quality of gas as a larger chain like Shell, BP or Mobile. Also what grade of gasoline was he using.

Either way this doesn't instill a lot of confidence in these motors. I am coming up on 15000 miles....might be looking into the BG top end service and adding a catch can.

I don't understand the gas argument. The issue is deposits forming on the backside of the valves from the PCV system where no fuel washes over them to clean them. I'm not that well versed in engines though. I pretty much just know major component names and locations haha. Are PCV gases created by burning fuel? And thus cleaner fuel can reduce deposits?

fondupot · February 5, 2015

I don't understand the gas argument. The issue is deposits forming on the backside of the valves from the PCV system where no fuel washes over them to clean them. I'm not that well versed in engines though. I pretty much just know major component names and locations haha. Are PCV gases created by burning fuel? And thus cleaner fuel can reduce deposits?

Yea ur right, I was still thinking in terms of traditional fuel injection where better gas would clean the valves. But in the case of DI using crappy gas wont make a difference on the valves much, it might clog the injectors...but still the back side of the valves aren't exposed. So my argument is invalid. lol

ndkid · February 5, 2015

Makes me wonder what kind of gas the OP was using. His info says he is from North Dakota. Nothing against ND, but its reasonable to assume hes using a smaller chain gas station that might not have the same quality of gas as a larger chain like Shell, BP or Mobile. Also what grade of gasoline was he using.

Either way this doesn't instill a lot of confidence in these motors. I am coming up on 15000 miles....might be looking into the BG top end service and adding a catch can.

Most gasoline around the area is supplied by Cenex (CHS) or Tesoro in this area. Most gasoline is 87 or 89 octane with almost all having 10% ethanol added.

TJay74 · February 5, 2015

With direct injection I doubt the deposits are from fuel, they are more than likely from the oil mist that comes thru the intake tract and then the extreme of the valves baking those deposits on the backside of the valves.

Yamiryder · February 6, 2015

I don't really see how the grade of fuel would affect the valves in the DI motors. However, has anyone used, say aerosol Seafoam, in their intake to try to clean the valves?

Stoddard · February 6, 2015

Actually guys its all from the cyljnder. I seen someone on the first page had it right. We don't have egr valves anymore and have variable timing. Buildup starts at the valves and progressively works up the intake ports. Its the variable timing and lack of fuel spray on the valves that causes this. I think its Mazda's "skyactive" that still has both sets of injectors and cycles between which ones it uses for flex fuel and purges the mpfi ones to wash the valves every so often. I know when I left the dealership a year ago, gm wasn't looking into walnut shells yet but seemed like the best way to clean them without taking the heads off but sounds like a lot of damn work. I'd say keep up on good fuel and do a intake flush service every 15-30k and probably would be fine. Ice seen terrible valves and good ones. Gm also has a pretty aggressive cleaner a guy could use carefully following GMs directions. Only thing is it smokes like crazy through the cats and stinks really bad.

02suburbanZ71 · February 6, 2015

How much is intake flush from dealership?

Stoddard · February 6, 2015

02suburbanz71 I forget how much it was. The process takes about 3 1/2 hours. You take a vacuum hose off the intake, rev the engine to 1500-2000 rpm and inject their cleaner into the engine when at operating temp. Then let it sit for 2 1/2 hours to soak in. Then drive it to burn the remains out. The engine smokes out the exhaust like its on fire haha and sometimes runs a little crappy as it passes the deposits and burns off the remaining cleaner but does a good job at keeping it clean. I'll attach the tsb talking about the fuels.

#05-06-04-022L: TOP TIER Detergent Gasoline Information and Available Brands - (Nov 21, 2014)

Subject: TOP TIER Detergent Gasoline Information and Available Brands

Models: 2015 and Prior GM Passenger Cars and Trucks

United States, Canada and Puerto Rico

Attention: Gasolines that have met the TOP TIER Detergent Standards will appear on the list of TOP TIER Gasoline brands at this website under the Retailers tab: www.toptiergas.com

This Bulletin has been revised to update the list of TOP TIER Gasoline Retailers. Please discard Corporate Bulletin Number 05-06-04-022K.

TOP TIER Detergent Gasoline —

A class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of various fuel marketers in the United States, Canada and Puerto Rico. This gasoline meets the detergent standards developed by seven automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the “Lowest Additive Concentration” (LAC). LAC is also known as the minimum detergent treat rate, recommended by the Environmental Protection Agency (EPA) in the United States and in Canada, the Canadian General Standards Board (CGSB). Those vehicles that have experienced engine deposit related concerns may especially benefit from using TOP TIER Detergent Gasoline.

GM strongly recommends the use of TOP TIER Detergent Gasoline. TOP TIER Detergent Gasoline is guaranteed not to contain harmful organometallic additives, which are sometimes used to raise a fuel’s octane rating and could harm the vehicle’s emission system.

The EPA and CGSB require only a minimum amount of detergent in gasoline. This minimum amount is not adequate to keep the engine running at optimal conditions for the life of the vehicle. TOP TIER Detergent gasoline contains 2–3 times more detergent than the EPA and CGSB minimum requirement, resulting in a lower amount of intake valve deposits (IVD). These IVD’s can negatively affect fuel economy, emissions, and performance.

General Motors, BMW, Honda, Toyota, Volkswagen, Audi and Mercedes-Benz developed the TOP TIER Detergent Gasoline Standards and support the use of TOP TIER Detergent Gasoline by recommending it in their vehicle Owner Manuals. All seven corporations recognize the benefits to the vehicle, the environment, and the consumer. Additionally, the companies recognize that by joining together they can better address the industry concern with low fuel detergency levels and the intentional addition of metallic additives.

Silverado-Hareek · February 6, 2015

02suburbanz71 I forget how much it was. The process takes about 3 1/2 hours. You take a vacuum hose off the intake, rev the engine to 1500-2000 rpm and inject their cleaner into the engine when at operating temp. Then let it sit for 2 1/2 hours to soak in. Then drive it to burn the remains out. The engine smokes out the exhaust like its on fire haha and sometimes runs a little crappy as it passes the deposits and burns off the remaining cleaner but does a good job at keeping it clean. I'll attach the tsb talking about the fuels.

#05-06-04-022L: TOP TIER Detergent Gasoline Information and Available Brands - (Nov 21, 2014)

Subject: TOP TIER Detergent Gasoline Information and Available Brands

Models: 2015 and Prior GM Passenger Cars and Trucks

United States, Canada and Puerto Rico

Attention: Gasolines that have met the TOP TIER Detergent Standards will appear on the list of TOP TIER Gasoline brands at this website under the Retailers tab: www.toptiergas.com

This Bulletin has been revised to update the list of TOP TIER Gasoline Retailers. Please discard Corporate Bulletin Number 05-06-04-022K.

TOP TIER Detergent Gasoline —

A class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of various fuel marketers in the United States, Canada and Puerto Rico. This gasoline meets the detergent standards developed by seven automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the “Lowest Additive Concentration” (LAC). LAC is also known as the minimum detergent treat rate, recommended by the Environmental Protection Agency (EPA) in the United States and in Canada, the Canadian General Standards Board (CGSB). Those vehicles that have experienced engine deposit related concerns may especially benefit from using TOP TIER Detergent Gasoline.

GM strongly recommends the use of TOP TIER Detergent Gasoline. TOP TIER Detergent Gasoline is guaranteed not to contain harmful organometallic additives, which are sometimes used to raise a fuel’s octane rating and could harm the vehicle’s emission system.

The EPA and CGSB require only a minimum amount of detergent in gasoline. This minimum amount is not adequate to keep the engine running at optimal conditions for the life of the vehicle. TOP TIER Detergent gasoline contains 2–3 times more detergent than the EPA and CGSB minimum requirement, resulting in a lower amount of intake valve deposits (IVD). These IVD’s can negatively affect fuel economy, emissions, and performance.

General Motors, BMW, Honda, Toyota, Volkswagen, Audi and Mercedes-Benz developed the TOP TIER Detergent Gasoline Standards and support the use of TOP TIER Detergent Gasoline by recommending it in their vehicle Owner Manuals. All seven corporations recognize the benefits to the vehicle, the environment, and the consumer. Additionally, the companies recognize that by joining together they can better address the industry concern with low fuel detergency levels and the intentional addition of metallic additives.

Sounds like you're describing the BG induction service. Supposedly BG products are the best on the market according to a mechanic I know. However I'm still on the fence about this. In talking to RX, they've seen scoring on cylinder walls due to these services pushing carbon particles through the system during the cleaning process and getting stuck between the ring seals and the cylinder walls. However BG will give you like a $4,000 engine warranty if you do their service every 15,000 miles so they stand behind it in that regard. I dunno I want to do more research on this.

haider320 · February 6, 2015

02suburbanz71 I forget how much it was. The process takes about 3 1/2 hours. You take a vacuum hose off the intake, rev the engine to 1500-2000 rpm and inject their cleaner into the engine when at operating temp. Then let it sit for 2 1/2 hours to soak in. Then drive it to burn the remains out. The engine smokes out the exhaust like its on fire haha and sometimes runs a little crappy as it passes the deposits and burns off the remaining cleaner but does a good job at keeping it clean. I'll attach the tsb talking about the fuels.

#05-06-04-022L: TOP TIER Detergent Gasoline Information and Available Brands - (Nov 21, 2014)

Subject: TOP TIER Detergent Gasoline Information and Available Brands

Models: 2015 and Prior GM Passenger Cars and Trucks

United States, Canada and Puerto Rico

Attention: Gasolines that have met the TOP TIER Detergent Standards will appear on the list of TOP TIER Gasoline brands at this website under the Retailers tab: www.toptiergas.com

This Bulletin has been revised to update the list of TOP TIER Gasoline Retailers. Please discard Corporate Bulletin Number 05-06-04-022K.

TOP TIER Detergent Gasoline —

A class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of various fuel marketers in the United States, Canada and Puerto Rico. This gasoline meets the detergent standards developed by seven automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the “Lowest Additive Concentration” (LAC). LAC is also known as the minimum detergent treat rate, recommended by the Environmental Protection Agency (EPA) in the United States and in Canada, the Canadian General Standards Board (CGSB). Those vehicles that have experienced engine deposit related concerns may especially benefit from using TOP TIER Detergent Gasoline.

GM strongly recommends the use of TOP TIER Detergent Gasoline. TOP TIER Detergent Gasoline is guaranteed not to contain harmful organometallic additives, which are sometimes used to raise a fuel’s octane rating and could harm the vehicle’s emission system.

The EPA and CGSB require only a minimum amount of detergent in gasoline. This minimum amount is not adequate to keep the engine running at optimal conditions for the life of the vehicle. TOP TIER Detergent gasoline contains 2–3 times more detergent than the EPA and CGSB minimum requirement, resulting in a lower amount of intake valve deposits (IVD). These IVD’s can negatively affect fuel economy, emissions, and performance.

General Motors, BMW, Honda, Toyota, Volkswagen, Audi and Mercedes-Benz developed the TOP TIER Detergent Gasoline Standards and support the use of TOP TIER Detergent Gasoline by recommending it in their vehicle Owner Manuals. All seven corporations recognize the benefits to the vehicle, the environment, and the consumer. Additionally, the companies recognize that by joining together they can better address the industry concern with low fuel detergency levels and the intentional addition of metallic additives.

Same thing I do with Seafoam. Unhook a vacuum line, suck in some Seafoam, let sit for a while, start it up and enjoy the smoke show. 8 dollars for Seafoam or hundreds of dollars from the dealer? I'll choose Seafoam..

Stoddard · February 6, 2015

Well its not BG. I have the part number on home. They don't recommend putting it into plastic fuel tanks haha. But I haven't seen how BG products work over time but I know they give mechanics and dealers spiffs for how much they sell.

gone_fishing · February 6, 2015

Makes me wonder what kind of gas the OP was using. His info says he is from North Dakota. Nothing against ND, but its reasonable to assume hes using a smaller chain gas station that might not have the same quality of gas as a larger chain like Shell, BP or Mobile. Also what grade of gasoline was he using.

Either way this doesn't instill a lot of confidence in these motors. I am coming up on 15000 miles....might be looking into the BG top end service and adding a catch can.

I run TopTier gas when I can but not all the time. The town I live in doesn't sell any TopTier gas. I travel quite a bit for my job so I try to find TopTier stations when on the road (usually Shell or Holiday).

I ran a can of this CRC Intake Valve cleaner through the engine a couple weeks ago: http://crcindustries.com/auto/intake-valve-cleaner.phpYou really can't tell if it cleaned anything unless I were to remove the intake manifold again (which I don't plan on doing anytime soon).

fondupot · February 6, 2015

I run TopTier gas when I can but not all the time. The town I live in doesn't sell any TopTier gas. I travel quite a bit for my job so I try to find TopTier stations when on the road (usually Shell or Holiday).

I ran a can of this CRC Intake Valve cleaner through the engine a couple weeks ago: http://crcindustries.com/auto/intake-valve-cleaner.phpYou really can't tell if it cleaned anything unless I were to remove the intake manifold again (which I don't plan on doing anytime soon).

How did you go about spraying that into the engine? What hose did you use?