Automotive

Carbon Build Up: Can it be DIY or should it be done at a shop?

  • Last Updated:
  • May 3rd, 2019 6:49 pm
[OP]
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Sep 6, 2007
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Carbon Build Up: Can it be DIY or should it be done at a shop?

I did an RFD search for other threads but I'm not too well versed on this subject matter.

My 2010 Toyota Matrix has 254,000+ km. My last visit for schedule maintenance they recommended engine cleaning for carbon build up (paraphrasing, pretty sure they used other terminology).

At the time I said no. They wanted $150 for it and said it was an additive they put in or something like that.

I know carbon build up can affect fuel economy and other things. I have the 2.4L and right now I get around 450km/tank (50L tank).

Could this crumby fuel economy be due to that? If so, is it worth spending $150 to get it done or is there a solution I can buy at CT and do it myself?

Again, I'm not well versed on this topic.
28 replies
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Here is an opinion...and it is a good one
The Government cannot give to anybody anything that the Government does not first take from somebody else.
Newbie
Feb 7, 2017
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You can clean out your throttle body with any generic carbon cleaner spray and a toothbrush yourself. Stay away from adding carbon cleaning products to oil as it can expose cracks and weaknesses.
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Sep 12, 2007
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Greely
I just had a carbon clean done last year - they soda blasted mine but walnut blasting is also common.

An additive will do pretty much nothing. Save your $$.
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Aug 22, 2011
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steve-0101 wrote: I just had a carbon clean done last year - they soda blasted mine but walnut blasting is also common.

An additive will do pretty much nothing. Save your $$.
Which shop?
Sr. Member
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Jun 21, 2009
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Your Matrix doesn't use direct injection, carbon buildup on intake valves should not be an issue. Save your $ if it's running smoothly.
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Jun 20, 2010
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I just cleaned my throttle body and IACV only because I experiencing throttle hesitation. I wouldn't spend the time and money (cleaner, gaskets) unless there is an issue.

Edit - long day..For actual carbon cleaning, I usually don't, but did run a bottle of Gumout Regane since I'm changing my fuel filter.
Last edited by eclone on May 1st, 2019 2:50 pm, edited 1 time in total.
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MoxGoat wrote: You can clean out your throttle body with any generic carbon cleaner spray and a toothbrush yourself. Stay away from adding carbon cleaning products to oil as it can expose cracks and weaknesses.
You do know that is not carbon cleaning? It is cleaning the intake of the throttle body.
What are you talking about " to oil as it can expose cracks and weaknesses"?? "Carbon" cleaners are added to the gas and primarily are to help clean the injectors.
The Government cannot give to anybody anything that the Government does not first take from somebody else.
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Marx0r wrote: Your Matrix doesn't use direct injection, carbon buildup on intake valves should not be an issue. Save your $ if it's running smoothly.
Yea, the shop basically wants to charge him $150 to pour $20 of engine cleaner in to his tank. Good on OP for questioning it. However, he could still have carbon build up if it's driven very gently and the PCV isn't working as well as it should. It wouldn't hurt to fill the tank with premium and add some good cleaner with PEA, like BG44K or Techron. Then drive the engine very hard to get it hot and help cook away the buildup.
https://www.amazon.ca/Chevron-65740-Tec ... B00092893E

Must cheaper from amazon.com if you can it there easily.
https://www.amazon.com/gp/product/B00092893E
https://www.amazon.com/BG-44K-System-Cl ... B00DDVU6EI

OP, there also other things you should check are that your tires are properly inflated, your brake pads aren't dragging, that your auto transmission is shifting into high gear properly, you don't have any engine codes, make sure you aren't carrying excessive junk/weight in your car.
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BluePhirePB wrote: I did an RFD search for other threads but I'm not too well versed on this subject matter.

My 2010 Toyota Matrix has 254,000+ km. My last visit for schedule maintenance they recommended engine cleaning for carbon build up (paraphrasing, pretty sure they used other terminology).

At the time I said no. They wanted $150 for it and said it was an additive they put in or something like that.

I know carbon build up can affect fuel economy and other things. I have the 2.4L and right now I get around 450km/tank (50L tank).

Could this crumby fuel economy be due to that? If so, is it worth spending $150 to get it done or is there a solution I can buy at CT and do it myself?

Again, I'm not well versed on this topic.
Also, when was the last time your spark plugs were changed? Have you ever changed or cleaned your injectors? Are you using the factory recommended oil spec?
Are you doing more city driving than usual? What's your hwy/city ratio?
[OP]
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Sep 6, 2007
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engineered wrote: Yea, the shop basically wants to charge him $150 to pour $20 of engine cleaner in to his tank. Good on OP for questioning it. However, he could still have carbon build up if it's driven very gently and the PCV isn't working as well as it should. It wouldn't hurt to fill the tank with premium and add some good cleaner with PEA, like BG44K or Techron. Then drive the engine very hard to get it hot and help cook away the buildup.
https://www.amazon.ca/Chevron-65740-Tec ... B00092893E

Must cheaper from amazon.com if you can it there easily.
https://www.amazon.com/gp/product/B00092893E
https://www.amazon.com/BG-44K-System-Cl ... B00DDVU6EI

OP, there also other things you should check are that your tires are properly inflated, your brake pads aren't dragging, that your auto transmission is shifting into high gear properly, you don't have any engine codes, make sure you aren't carrying excessive junk/weight in your car.
engineered wrote: Also, when was the last time your spark plugs were changed? Have you ever changed or cleaned your injectors? Are you using the factory recommended oil spec?
Are you doing more city driving than usual? What's your hwy/city ratio?
Tires - pressure checked regularly and all to spec
Brakes - done all within the last 12-18 months and get them serviced annually
Engine codes - I own an OBD2 sensor and there are no codes. Last one was a faulty O2 sensor which was replaced by OEM Denso part
No excess weight in car
Spark plugs - changed about 3000 km ago
Injector cleaning - I don't think this has ever been done. Is this something different than the carbon build up?
All oil changes are done at Toyota with OEM oil as recommended.
I'm traveling along Trafalgar most of the time so not city but not highway.
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BluePhirePB wrote: Tires - pressure checked regularly and all to spec
Brakes - done all within the last 12-18 months and get them serviced annually
Engine codes - I own an OBD2 sensor and there are no codes. Last one was a faulty O2 sensor which was replaced by OEM Denso part
No excess weight in car
Spark plugs - changed about 3000 km ago
Injector cleaning - I don't think this has ever been done. Is this something different than the carbon build up?
All oil changes are done at Toyota with OEM oil as recommended.
I'm traveling along Trafalgar most of the time so not city but not highway.
Well, you can clean the injectors with the additives I mentioned, but you can also have them removed and cleaned if needed.
Were plugs changed with correct parts and gapped properly?
How recently did your problems start? Sounds like it might have been related to recent service. Or has it been a gradual decline?
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@OP
Don't bother with a carbon cleaning on that 2.4L

Now what you should be looking out for on that specific 2.4L is oil consumption because that engine is known for issues with it's Piston rings and that could be the main reason why you're having terrible gas mileage (low of compression)

With regard to Scotty Kilmore. Man I hate that guy. Not that once in a while he doesn't makes a decent point but he's usually full of half cocked advice. And he's just irritating as hell to watch.
[OP]
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Sep 6, 2007
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2008 upvotes
engineered wrote: Well, you can clean the injectors with the additives I mentioned, but you can also have them removed and cleaned if needed.
Were plugs changed with correct parts and gapped properly?
How recently did your problems start? Sounds like it might have been related to recent service. Or has it been a gradual decline?
Plugs were done at Toyota with genuine parts. I trust this dealership.
It's been a gradual decline but the car is 10 years old with decent mileage.
tebore wrote: @OP
Don't bother with a carbon cleaning on that 2.4L

Now what you should be looking out for on that specific 2.4L is oil consumption because that engine is known for issues with it's Piston rings and that could be the main reason why you're having terrible gas mileage (low of compression)

With regard to Scotty Kilmore. Man I hate that guy. Not that once in a while he doesn't makes a decent point but he's usually full of half cocked advice. And he's just irritating as hell to watch.
I already had the pistons replaced under the recall. It got so bad that I'd get the low oil level light 1500km before the 8000km oil change and it wouldn't even show the level on the dipstick. I had that done about a year ago.
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tebore wrote: @OP
Don't bother with a carbon cleaning on that 2.4L

Now what you should be looking out for on that specific 2.4L is oil consumption because that engine is known for issues with it's Piston rings and that could be the main reason why you're having terrible gas mileage (low of compression)

With regard to Scotty Kilmore. Man I hate that guy. Not that once in a while he doesn't makes a decent point but he's usually full of half cocked advice. And he's just irritating as hell to watch.
+1 about Scotty, he has just enough knowledge to be dangerous, and loves to rant.

Project Farm on the other hand is humble and does his best to do somewhat scientific tests.

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BluePhirePB wrote: Plugs were done at Toyota with genuine parts. I trust this dealership.
It's been a gradual decline but the car is 10 years old with decent mileage.

I already had the pistons replaced under the recall. It got so bad that I'd get the low oil level light 1500km before the 8000km oil change and it wouldn't even show the level on the dipstick. I had that done about a year ago.
The only thing I can think of is after 235k KM Your O2 sensors could be out of calibration (not enough to set off an check engine light).

Usually driving conditions and habits have the largest affect on gas mileage tho. Some people may not notice that lights could be reprogrammed or traffic has gotten gradually heavier on their daily routes.
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tebore wrote: @OP
Don't bother with a carbon cleaning on that 2.4L
.....

With regard to Scotty Kilmore. Man I hate that guy. Not that once in a while he doesn't makes a decent point but he's usually full of half cocked advice. And he's just irritating as hell to watch.
engineered wrote: +1 about Scotty, he has just enough knowledge to be dangerous, and loves to rant.
...
But in this case, he is right.
The Government cannot give to anybody anything that the Government does not first take from somebody else.
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Pete_Coach wrote: But in this case, he is right.
Didn't even bother to watch his garbage.
Not willing to give him the view.
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I have a 2005 Nissan Altima 2.5 SL that we got in 2007. Runs perfect, no mechanical issues ever, currently has almost 220,000 km on it.

It's rated for 10.1L/100km but the dash for the past few years says we consume 11.2L/100km.

I know it's around an extra $300 in fuel per year based on the amount we drive it.

I asked around on a few Nissan forums about the 10% increase in fuel consumption and the car experts there told me to look into these things
When was the air filter last replaced?
Have you ever replaced the spark plugs?
Using an OBDII code reader what are your short and long term fuel trims?
Have you tried any MAF sensor cleaner?
What about your alignment?
Also, do you track your mileage consistently? If so, Has it slowly gotten less over time or has it dropped off quickly?
Have your driving habits or Road conditions changed?
Have you bought 'stickier' tires recently?

You're talking about a ~10% difference and tires, alignment, driving style, etc. could easily make your mileage change individually by themselves.

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