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OK, I have read a lot of the info out there that intake valves in GDI engines can build up carbon, etc. and it needs to be cleaned occasionally. Paying someone to remove and reinstall the intake manifold so they can use walnut shell chips to blast the valves sounds expensive for a car with 25K miles. Also I don't have any symptoms. However, when I take the car in for service at the dealer they always want to upsell me on some snake oil of some kind, and this is the latest. I can't imagine they will remove the intake manifold, and if they do, I fear the price. Also I have caught them a couple of times indicating things were done, that were not. This includes cabin air filter changes and a tire rotation
So I am interested in products like the CRC GDI IV cleaner. You are warned to do everything downstream of the MAF. My MAF appears to be buried such that removing hoses and such would be a PITA. Immediately after the MAF, the intake manifold splits into 4 runners. There are a couple of vacuum hoses, one appearing to be crankcase ventilation, and the other unknown. The crankcase draw feeds directly into the runner fro the number 1 cylinder and the other is a small tube kind of between the #3 and #4 runners. Basically squirting something in either tube is going to tend to dump into some cylinders much more so than others. So how does one accomplish getting all of the intake valves clean using an off the shelf product?
Thanks in advance!
 

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OK, I have read a lot of the info out there that intake valves in GDI engines can build up carbon, etc. and it needs to be cleaned occasionally. Paying someone to remove and reinstall the intake manifold so they can use walnut shell chips to blast the valves sounds expensive for a car with 25K miles. Also I don't have any symptoms. However, when I take the car in for service at the dealer they always want to upsell me on some snake oil of some kind, and this is the latest. I can't imagine they will remove the intake manifold, and if they do, I fear the price. Also I have caught them a couple of times indicating things were done, that were not. This includes cabin air filter changes and a tire rotation
So I am interested in products like the CRC GDI IV cleaner. You are warned to do everything downstream of the MAF. My MAF appears to be buried such that removing hoses and such would be a PITA. Immediately after the MAF, the intake manifold splits into 4 runners. There are a couple of vacuum hoses, one appearing to be crankcase ventilation, and the other unknown. The crankcase draw feeds directly into the runner fro the number 1 cylinder and the other is a small tube kind of between the #3 and #4 runners. Basically squirting something in either tube is going to tend to dump into some cylinders much more so than others. So how does one accomplish getting all of the intake valves clean using an off the shelf product?
Thanks in advance!

If you don't have any symptoms, why are you considering this? What has to happen to cause carbon build-up on an intake valve that is to only control air entering the cylinder?
Can you get carbon build-up with indirect injection, if so, how come?
 

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Ive used the CRC GDI cleaner as shown on the other thread once at 15,000 moles and Im going to do it this week as Im due for a 28,000 mile service (oil and filter i do every 5000), I also add a bottle of Techon Complete Fuel System Cleaner (same product as the Hyundai Cleaner, can be found on ebay or amazon at 1/2 price) or a cann of BG 44K every 5000 miles even though the manual says it is not needed if using top tier fuel. To me its cheap service insurance. The Fuel System cleaner helps keep the injectors clean. The CRC GDI Cleaner helps clean the turbo and the intake and intake valves. Easy to do takes 10-15 minutes and the cost of a can is less than $15 usually closer to $12.

I cant speak to the 2.4 but the 2.0T engine does not use a MAF sensor it uses a MAP so you can spray the intake system/valve cleaner in any where after the air cleaner. See the attached thread above. I did it this way as well loosen the clamp at the air filter box (I removed the and change the air filter after doing this) slip the tube from the CRC spray can into the intake hose and spray it into the engine as it is running per instructions, when empty immediately shut off and let sit (they call it hot soak) for 1 hour and then take it out for a drive.

I have not seen a lot of smoke or even engine stumbling as it is done, but maybe that is due to no carbon to clean on my engine, I dont know but I drive in sport mode most of the time, daily often run it up to 5500-6000 rpm accelerating and a lot of my driving is hwy at 65-85 mph.

I know BG makes a system to flood the intake and clean it and Im sure there are others out there , just as a lot of BMW service they do the walnut blasting.

I cant say that it works or will guarantee no intake valve build up, but CRC has been around a long time and I think if you stay ahead of any build up it is more likely to be able to kep the intake clean if there is not much buildup. So for less than $ 15 every 5000 miles and another $ 12-15 every 15,000 miles its cheap , easy preventive maintenance. especially compared to the $ 150 fuel injector service the dealer wants to charge.

I also always use these products immediately before changing the oil just in case any gets into the crankcase and dilutes the oil since this is a GDI problem anyway, fresh oil and filter after using the cleaners seems right to me.

None of this is required in the service manual as long as you use top tier fuel but for me I think it cant hurt.
 

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Discussion Starter #6
If you don't have any symptoms, why are you considering this? What has to happen to cause carbon build-up on an intake valve that is to only control air entering the cylinder?
Can you get carbon build-up with indirect injection, if so, how come?
The issue is blow by and other crud gets pulled back into the intake ia positive crankcase ventilation (PCV). Since there is no fuel, with cleaners, to wet and wash the intake valves, you get build up.

Ford and Toyota actually use direct AND port injectors in part to deal with this issue.
 

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Ive used the CRC GDI cleaner as shown on the other thread once at 15,000 moles and Im going to do it this week as Im due for a 28,000 mile service (oil and filter i do every 5000), I also add a bottle of Techon Complete Fuel System Cleaner (same product as the Hyundai Cleaner, can be found on ebay or amazon at 1/2 price) or a cann of BG 44K every 5000 miles even though the manual says it is not needed if using top tier fuel. To me its cheap service insurance. The Fuel System cleaner helps keep the injectors clean. The CRC GDI Cleaner helps clean the turbo and the intake and intake valves. Easy to do takes 10-15 minutes and the cost of a can is less than $15 usually closer to $12.

I cant speak to the 2.4 but the 2.0T engine does not use a MAF sensor it uses a MAP so you can spray the intake system/valve cleaner in any where after the air cleaner. See the attached thread above. I did it this way as well loosen the clamp at the air filter box (I removed the and change the air filter after doing this) slip the tube from the CRC spray can into the intake hose and spray it into the engine as it is running per instructions, when empty immediately shut off and let sit (they call it hot soak) for 1 hour and then take it out for a drive.

I have not seen a lot of smoke or even engine stumbling as it is done, but maybe that is due to no carbon to clean on my engine, I dont know but I drive in sport mode most of the time, daily often run it up to 5500-6000 rpm accelerating and a lot of my driving is hwy at 65-85 mph.

I know BG makes a system to flood the intake and clean it and Im sure there are others out there , just as a lot of BMW service they do the walnut blasting.

I cant say that it works or will guarantee no intake valve build up, but CRC has been around a long time and I think if you stay ahead of any build up it is more likely to be able to kep the intake clean if there is not much buildup. So for less than $ 15 every 5000 miles and another $ 12-15 every 15,000 miles its cheap , easy preventive maintenance. especially compared to the $ 150 fuel injector service the dealer wants to charge.

I also always use these products immediately before changing the oil just in case any gets into the crankcase and dilutes the oil since this is a GDI problem anyway, fresh oil and filter after using the cleaners seems right to me.

None of this is required in the service manual as long as you use top tier fuel but for me I think it cant hurt.
I haven't used anything but top tier fuels for the last 4 cars. A SAAB Turbo, a VW R32, A Sonata Hybrid, and this Sonata 2.4. I have not seen any fuel related issues, but I usually trade cars based on time, and not mileage. Case in point, I purchase the current Sonata on Black Friday in 2014 and I crossed 25K earlier this month.

I admit I took a quick look, but there appears to be a MAF just upstream from the intake manifold and it is downstream of the air filter. Come to think of it, where is the throttle body on this engine? Since it is throttle by wire, it could be most anywhere in the intake path. It is possible my quick look mistook the throttle body for a MAF.

Darn it now I have to look again, and this time look for a MAP too in case there is no MAF. If there is no MAF or I can find a place downstream of the MAF if there is one, spraying cleaner is no problem.

Looks like I have a Saturday afternoon project to look at things again.
 

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The walnut shell cleaning is in very, VERY extreme cases. Or a BMW.

Local dealer recommends the Hyundai equivalent of CRC every 40K miles, or when rough idle/hard start occurs. Nothing gets removed from the engine, it does indeed use a MAP sensor (I asked) on the 2.0l GDI and 2.4l non-turbo engines. From reading about the procedure, and talking to the technician, the process isn't difficult, it just has several steps that require performing, come back later, perform, come back later, just as the CRC video above discusses. Hence the higher dealer cost. Not hard to do, just involves time.
 

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I haven't used anything but top tier fuels for the last 4 cars. A SAAB Turbo, a VW R32, A Sonata Hybrid, and this Sonata 2.4. I have not seen any fuel related issues, but I usually trade cars based on time, and not mileage. Case in point, I purchase the current Sonata on Black Friday in 2014 and I crossed 25K earlier this month.

I admit I took a quick look, but there appears to be a MAF just upstream from the intake manifold and it is downstream of the air filter. Come to think of it, where is the throttle body on this engine? Since it is throttle by wire, it could be most anywhere in the intake path. It is possible my quick look mistook the throttle body for a MAF.

Darn it now I have to look again, and this time look for a MAP too in case there is no MAF. If there is no MAF or I can find a place downstream of the MAF if there is one, spraying cleaner is no problem.

Looks like I have a Saturday afternoon project to look at things again.
The Hyundai 2.0 and 2.4 use a MAP so their is no problem with damaging a air flow sensor (hot wire)
See this thread with picture of location

http://www.hyundai-forums.com/lf-2015-sonata-i45/626898-map-maf-sensor.html
 

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I used the CRC intake cleaner on mine at 15K and plan on doing it every 10-15K as regular maintenance. I just pulled the hose from the top of the engine for the PCV and put it in there because that goes right to the throttle body.
 

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I used it last night, total time less than 10 min and then sit for an hour and take out for spirited drive to clear out any residual product. Last night I was also changing the air filter so I removed the air filter and added 10" of drip line hose that fit tightly to the straw on the CRC can and then just inserted through the air cleaner box about 5" into the intake and propped a 4x4 block on the gas pedal to hold 2000 rpm. Then administered as the directions said in short bursts a couple times the engine stumbled and I stopped and it cleaned out . Was able to do the whole can in 10 min. let the car idle for a couple minutes and then shut off to "heat soak" for 1 hr, finishing by taking it out for a 2-3 mile drive with some 0-80 runs and rpms in the 4500-5500 range. Then installed a new air filter, will change oil and filter today.

Here is another link to CRC and has some Sonata before and after shots.
CRC Intake Valve Cleaner

I'll continue to use about every 15000 -20000 miles and a bottle of Techron Complete system Cleaner or can of BG44K just for piece of mind. For the appox $ 12 for the CRC and $10-12 for the Techron from ebay or amazon sellers when you buy 4-6 at a time its over $ 100 less than the dealer injection treatment. I guess that if later I do have loss of power, decrease in MPG pr rough idle then I might try the dealers treatment of find a garage that uses BG products and have them do the GDI cleaning with their GDI system.
 

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The issue is blow by and other crud gets pulled back into the intake ia positive crankcase ventilation (PCV). Since there is no fuel, with cleaners, to wet and wash the intake valves, you get build up.

Ford and Toyota actually use direct AND port injectors in part to deal with this issue.

What causes the blow-by and other crud; and what do you do to prevent it?
 

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Ive used the CRC GDI cleaner as shown on the other thread once at 15,000 moles and Im going to do it this week as Im due for a 28,000 mile service (oil and filter i do every 5000), I also add a bottle of Techon Complete Fuel System Cleaner (same product as the Hyundai Cleaner, can be found on ebay or amazon at 1/2 price) or a cann of BG 44K every 5000 miles even though the manual says it is not needed if using top tier fuel. To me its cheap service insurance. The Fuel System cleaner helps keep the injectors clean. The CRC GDI Cleaner helps clean the turbo and the intake and intake valves. Easy to do takes 10-15 minutes and the cost of a can is less than $15 usually closer to $12.

I cant speak to the 2.4 but the 2.0T engine does not use a MAF sensor it uses a MAP so you can spray the intake system/valve cleaner in any where after the air cleaner. See the attached thread above. I did it this way as well loosen the clamp at the air filter box (I removed the and change the air filter after doing this) slip the tube from the CRC spray can into the intake hose and spray it into the engine as it is running per instructions, when empty immediately shut off and let sit (they call it hot soak) for 1 hour and then take it out for a drive.

I have not seen a lot of smoke or even engine stumbling as it is done, but maybe that is due to no carbon to clean on my engine, I dont know but I drive in sport mode most of the time, daily often run it up to 5500-6000 rpm accelerating and a lot of my driving is hwy at 65-85 mph.

I know BG makes a system to flood the intake and clean it and Im sure there are others out there , just as a lot of BMW service they do the walnut blasting.

I cant say that it works or will guarantee no intake valve build up, but CRC has been around a long time and I think if you stay ahead of any build up it is more likely to be able to kep the intake clean if there is not much buildup. So for less than $ 15 every 5000 miles and another $ 12-15 every 15,000 miles its cheap , easy preventive maintenance. especially compared to the $ 150 fuel injector service the dealer wants to charge.

I also always use these products immediately before changing the oil just in case any gets into the crankcase and dilutes the oil since this is a GDI problem anyway, fresh oil and filter after using the cleaners seems right to me.

None of this is required in the service manual as long as you use top tier fuel but for me I think it cant hurt.

How is air flow measured and fuel injection timing adjusted without a MAF sensor?
 

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How is air flow measured and fuel injection timing adjusted without a MAF sensor?
MAP (Manifold Air Pressure) instead of MAF (manifold Air Flow). the MAP is located right on the intake manifold as shown in the picture in the previously attached link
 

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MAP (Manifold Air Pressure) instead of MAF (manifold Air Flow). the MAP is located right on the intake manifold as shown in the picture in the previously attached link

I expect that both MAP (Manifold Absolute Pressure) and MAF (Mass Air Flow) sensors would be required.
 

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What causes the blow-by and other crud; and what do you do to prevent it?
Some blow-by is an inevitable result of internal combustion engines. The PCV system attempts to scavenge it back into the combustion process to burn it off. Older cars just had a "road draft tube" to exit it into the atmosphere. When the piston rings are in good shape there is very little blow-by, as they wear, more gasses leak past them into the crankcase.

Also, some oil vapor is created by the mechanical agitation of the rotating assembly. This is also recycled by the PCV system. There is no way to completely prevent blow-by but it can be lessened by keeping the oil changed per schedule and keeping the engine in good tune.

https://www.google.com/search?q=blo...by&aqs=chrome..69i57&sourceid=chrome&ie=UTF-8
 

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OK, I have read a lot of the info out there that intake valves in GDI engines can build up carbon, etc. and it needs to be cleaned occasionally. Paying someone to remove and reinstall the intake manifold so they can use walnut shell chips to blast the valves sounds expensive for a car with 25K miles. Also I don't have any symptoms. However, when I take the car in for service at the dealer they always want to upsell me on some snake oil of some kind, and this is the latest. I can't imagine they will remove the intake manifold, and if they do, I fear the price. Also I have caught them a couple of times indicating things were done, that were not. This includes cabin air filter changes and a tire rotation
So I am interested in products like the CRC GDI IV cleaner. You are warned to do everything downstream of the MAF. My MAF appears to be buried such that removing hoses and such would be a PITA. Immediately after the MAF, the intake manifold splits into 4 runners. There are a couple of vacuum hoses, one appearing to be crankcase ventilation, and the other unknown. The crankcase draw feeds directly into the runner fro the number 1 cylinder and the other is a small tube kind of between the #3 and #4 runners. Basically squirting something in either tube is going to tend to dump into some cylinders much more so than others. So how does one accomplish getting all of the intake valves clean using an off the shelf product?
Thanks in advance!
I use RXP every 4-5 tanks and that is a carbon buildup killer and I can tell the difference is smoother acceleration and better pick up when I use it.
(I don't sell it, I just know it works as I've seen cars fail carbon emission tests and then after 2 tanks of RXP pass with a very respectable improvement.)

https://rxpfuel.com/pay-online.php
 

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The design of a GDI engine does not have fuel flowing past the intake valves so how do you suppose a gas treatment cleans those valves? A more correct approach is sea foam I think.
 

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If you have a Costco membership the Techron cleaner is in a 6 pack case there for less than $20. (at mine anyway) Not sure how many gallons a bottle will do so you might need to use 2 per treatment. I use the Top Tier gas there but have noticed that the car seems to run better on Sunoco fuel so I may just run the Sunoco and add the cleaner as needed. (depending on cost of fuel)
 
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