How to clean carbon on valves? - Reply to Topic

Reply to Thread

Post a reply to the thread: How to clean carbon on valves?

Your Message

 

You may choose an icon for your message from this list

Register Now

Additional Options

  • Will turn www.example.com into [URL]http://www.example.com[/URL].

Topic Review (Newest First)

  • June 2nd, 2019, 06:55 AM
    knalex01

    Re: How to clean carbon on valves?

    Quote Originally Posted by cdocksey View Post
    Oh Oh... definately the air intake side... I am talking exactly about that....
    Ok, lets see...... there are 2 carbon build ups that can prevent a good "seal", or proper valve closure.
    1) the dirt/dust form of carbon etc on the valve stem, which avoids good sliding within the guide and sometimes hinders the valve from fully closing. Here is where we discuss whether CRC, brushes and walnut blasting etc may help....
    2) the carbon build up on that same side of the valve, but on the edge..... on the chamfer edge which is where it seats perfectly to "seal" when closed. If there is irregular carbon build up on that chamfered border, then you will have a leak. This is where I don't see how you can clean this with walnut blasting.... or CRC either. If valve is closed, the walnut won't get to it, and if open, all the blasting will enter the combustion chamber which you don't want...
    Now... if we could find a way to clean that chamfered edge by "rubbing"it with CRC somehow, then we might have something. All depends how "quick acting" the CRC is.

    Sent from my SM-G950U1 using Tapatalk
    Valve seal is not the issue, smooth airflow is the issue.
  • June 2nd, 2019, 06:51 AM
    knalex01

    Re: How to clean carbon on valves?

    Quote Originally Posted by Roman NJ View Post
    CDOCKSEY, you do missing the point. The carbon build up is on the inner side of the valve, the side facing the intake not a combustion chamber.
    Dear OP- Knalex01, would you please post some pictures of contaminated valves. It should help the crowd to get a better understanding. If you really want have the understanding of the issue, type "GDI engine issue" in Youtube. Articles are plentiful and very educational.
    Ask and ye shall receive. Took these yesterday. The quality is not terrific - these are taken with an endoscope that I bought off amazon that connects to your cell phone. I bought it so I could make absolutely sure the valves are closed and it works well.

    Note the "crystalline" nature of the carbon (you can see it is shiny and reflects light), which is exactly how the engineering firm I mentioned earlier described this stuff. It's rock hard, there is no way in hell a chemical cleaner would get this stuff off, at least not in any reasonable amount of time.

    Attachment 273216

    Attachment 273218

    Attachment 273220
  • May 31st, 2019, 05:43 PM
    cdocksey

    Re: How to clean carbon on valves?

    Oh Oh... definately the air intake side... I am talking exactly about that....
    Ok, lets see...... there are 2 carbon build ups that can prevent a good "seal", or proper valve closure.
    1) the dirt/dust form of carbon etc on the valve stem, which avoids good sliding within the guide and sometimes hinders the valve from fully closing. Here is where we discuss whether CRC, brushes and walnut blasting etc may help....
    2) the carbon build up on that same side of the valve, but on the edge..... on the chamfer edge which is where it seats perfectly to "seal" when closed. If there is irregular carbon build up on that chamfered border, then you will have a leak. This is where I don't see how you can clean this with walnut blasting.... or CRC either. If valve is closed, the walnut won't get to it, and if open, all the blasting will enter the combustion chamber which you don't want...
    Now... if we could find a way to clean that chamfered edge by "rubbing"it with CRC somehow, then we might have something. All depends how "quick acting" the CRC is.

    Sent from my SM-G950U1 using Tapatalk
  • May 29th, 2019, 10:06 AM
    jhartz

    Re: How to clean carbon on valves?

    That is correct. The carbon build up is on the air intake side of the valves, not the combustion chamber/injection side. I think that the Engineering firm's answer is wrong for this problem. The CRC solution would clean off most of the carbon buildup on the valve stems without ever effecting the pistons or rings. The walnut dust solution would work, but I am concerned about how that would spatter the top of the piston and underside (combustion side) of the valves as some of the dust would surely bleed through at start up (unless you have an incredibly strong vacuum cleaner). When I had it done on a BMW (325IS), it was not with a direct injection mill; worked well, cost too much for what little gain I saw at WOT.

    I think you could get the same results by washing the stems with the CRC solution before reinstalling the manifold and SC. You have the system open for observation; spray it, bottle brush the stems; close it up and see if it runs better. The stuff will dry before you are done.
  • May 28th, 2019, 06:05 PM
    Roman NJ

    Re: How to clean carbon on valves?

    CDOCKSEY, you do missing the point. The carbon build up is on the inner side of the valve, the side facing the intake not a combustion chamber.
    Dear OP- Knalex01, would you please post some pictures of contaminated valves. It should help the crowd to get a better understanding. If you really want have the understanding of the issue, type "GDI engine issue" in Youtube. Articles are plentiful and very educational.
  • May 26th, 2019, 11:25 AM
    cdocksey

    Re: How to clean carbon on valves?

    Maybe i'm missing something, but if your valves are closed when you walnut blast, you're never getting to the carbon that you want to really get rid of.... the one that disturbs proper seating of the valve. As its closed, the blasting can't get to it.

    Sent from my SM-G950U1 using Tapatalk
  • May 26th, 2019, 06:22 AM
    knalex01

    Re: How to clean carbon on valves?

    Hi folks, just an update on this. I have been speaking with the guys at Elite Engineering regarding an oil catch can system to fix this carbon coking problem on my RRS. These guys know their stuff (and in fact have patents on some of their products). More to come on that later (I'm actually going to be a test mule for them).

    They absolutely do NOT recommend intake valve cleaner for GDI - here is their response when I inquired why they don't recommend it for Gasoline Direct Injection engines:

    These are safe with old port injection engines that only built up "soft carbon" on the piston tops and combustion chambers as it would most all be expelled out the exhaust with no damage. GDI engines are very different. With no fuel spraying on the backsides of the valves to keep them cool and clean, the coking is on the valves backsides, and as the valves in a GDI engine operate at such high temperatures these deposits form what is referred to as "Hard Carbon". It changes in structure to a crystalline form that is as hard as sand, and just as abrasive. Combine this with the intense cylinder pressures as fuel is introduced milliseconds prior to spark ignition, at as high as 3000 PSI (next few years will see 5,000 PSI plus) it forces a good deal of raw fuel past the rings to wash down the cylinder walls and piston skirts. It also will push some of this hard particulate matter down as well. This causes scouring in every engine we have torn down after an engine running solvent based upper induction cleaning. Then you have this particulate matter also contaminating the engine oil. So we cannot in any way condone these on GDI engines. This is very alarming as BG, Seafoam, CRC, etc. (BG this has been their core product for decades, so they do NOT want the general public to know this as the company would lose its main market overnight) are pushing these more and more. So, if you look at BG's site, they claim "up to 40% will be removed from the valves" when we have yet to see more than app. 20%. Then the damage (see attached pictures) is so not worth risking. It is relatively minor scouring, but after multiple uses becomes severe enough to cause excessive blow-by and oil consumption issues. So I would NEVER use these unless possibly at say starting at 10k miles or less and see. That we have not studied yet to see the effects. The other thing that is devastating to Forced Induction GDI engines is LSPI (Low Speed Pre Ignition). This breaks pistons no matter how strong at the compression ringland. Our systems with full time evacuation eliminate most of these incidences as well as Amsoil, M1, and other big name Synthetic oil makers had changed formulation of the oils to be less explosive when mixed with the excess fuel entering the crankcase. 5-6 years ago this was rampant as the cause of engine failures. It boils down to the industry does NOT want the consumer, the Automotive techs, nor the Dealers to know all of these issues. The secondary market (used cars) as well as the aftermarket warranty companies will face huge liabilities as these engines reach 50-100k miles and have high rates of failures. The industry only cares about selling new vehicles and thats why engine/drivetrain warranties have fallen from an industry standard of 100k miles to 60, 50, even as low as 36k miles for GDI powered vehicles. The expected trouble free lifespan is now 50k miles on these engines if steps are not taken to avoid these issues.


    I have attached the picture they mention above.

    Attachment 273016
  • May 22nd, 2019, 07:30 AM
    jhartz

    Re: How to clean carbon on valves?

    I think I would stick with the CRC solution: spray the stuff around the valve stems while you have the manifold off. Put it back together. Start it (see the smoke), let it clear then with a helper run the straw into the air duct upstream from the MAF and keep it at high idle. Pull the straw, Once the the idle settles; go to the other side. Probably better than good enough.
  • May 21st, 2019, 06:02 PM
    mik3ypl

    Re: How to clean carbon on valves?

    I have seen it done, some of the media gets through, thatís why walnut media is used because itís soft enough that when some of it gets through to cylinder heads it just burns off without damaging the pistons, but depending how much pressure you use and how much of it you vacuums out I have seen the media coming out of injector ports and clogging the actual injectors. Not saying itís always the case but when it comes to Range Rovers is not recommend by a trusted guy, but every one has a trusted guy with a different opinion/experience lol
  • May 21st, 2019, 01:12 PM
    knalex01

    Re: How to clean carbon on valves?

    Quote Originally Posted by mik3ypl View Post
    Problem is if you don’t do it right it can clog up your injectors and you’ll be getting misfires. Make sure you close your valves as you’re doing it.
    Not sure how this could clog up injectors on a Direct Injection engine??????? The blasting media would never come into contact with the injectors.

    Yes, the valves absolutely have to be closed, it would be insane to do it any other way.
  • May 21st, 2019, 10:02 AM
    mik3ypl

    Re: How to clean carbon on valves?

    Problem is if you donít do it right it can clog up your injectors and youíll be getting misfires. Make sure you close your valves as youíre doing it.
  • May 21st, 2019, 04:45 AM
    knalex01

    Re: How to clean carbon on valves?

    Quote Originally Posted by Special Ed View Post
    Blasting the valves works very well, some manufacturers are using it at the dealer (Mini and BMW) to clean the valves, We bought a kit to do the service and to warn you it is a total mess but does a very good job. Easy access when you have the supercharger pulled up. The CRC does not break chunks off to run through the engine, it is safe to run though the supercharger and breaks down (softening) the hardened carbon on the valves (makes it gummy) If you use the CRC like a preventative measure periodically it can keep the amount of carbon down as to prevent valve stick. it is definitely not a cure all or a fix but from what i have seen myself i am going to keep using it. I tried a bunch of different chemicals on one of the heads i have laying around the shop and other than the parts dip(would never use that in an engine) the CRC did better then anything else.

    As for blasting the valves you can buy the kit at harbor freight and use a shop vac. (same kit we bought from a specialty shop for a few hundred dollars more.) I ended up with 2 of them not knowing they were the same thing.

    As for the catch can I just had the wifes supercharger off and what a difference. I installed a catch can on it a year ago and the amount of oil getting sucked through to the intake from the pcv is drastically reduced(used a good catch can not cheapie internet thing) the comparison is night and day compared to the other superchargers i have had off in the last couple weeks.

    You can blast the valves without making a mess. I just bought this kit on ebay since there is not a Range Rover specific adapter:

    Attachment 272906

    I'm confident at least one of those adapters will be very, very close to fitting, if not perfect. I will post which one works best for my RRS so that folks can just buy the one adapter.

    You insert the adapter into the intake port on the head. Then you hook a shop vac to the end while you insert a compressor wand into the small hole and blow in the walnut media. In other words you blow and suck at the same time.

    Evidently BMW came up with this idea a while back and a lot of folks have started 3D printing various vacuum attachments.

    And yes, I absolutely plan to start running CRC through my engine, just prior to each oil change.

    Can you post pics or a DIY of your catch can setup? Especially the various fittings, etc. I'm very familiar with catch cans - I created a dual catch can setup on my 2002 BMW M5 since I hated how the factory "oil separator" system was set up.

    I hadn't really thought about doing a catch can setup on the RRS until your suggestion. Now I think I will. There is a fair amount of oil coating the inside of charge cooler, etc. In fact, right behind the throttle body there was actually a sizeable puddle of oil . . . .
  • May 20th, 2019, 08:36 PM
    Special Ed

    Re: How to clean carbon on valves?

    Blasting the valves works very well, some manufacturers are using it at the dealer (Mini and BMW) to clean the valves, We bought a kit to do the service and to warn you it is a total mess but does a very good job. Easy access when you have the supercharger pulled up. The CRC does not break chunks off to run through the engine, it is safe to run though the supercharger and breaks down (softening) the hardened carbon on the valves (makes it gummy) If you use the CRC like a preventative measure periodically it can keep the amount of carbon down as to prevent valve stick. it is definitely not a cure all or a fix but from what i have seen myself i am going to keep using it. I tried a bunch of different chemicals on one of the heads i have laying around the shop and other than the parts dip(would never use that in an engine) the CRC did better then anything else.

    As for blasting the valves you can buy the kit at harbor freight and use a shop vac. (same kit we bought from a specialty shop for a few hundred dollars more.) I ended up with 2 of them not knowing they were the same thing.

    As for the catch can I just had the wifes supercharger off and what a difference. I installed a catch can on it a year ago and the amount of oil getting sucked through to the intake from the pcv is drastically reduced(used a good catch can not cheapie internet thing) the comparison is night and day compared to the other superchargers i have had off in the last couple weeks.
  • May 20th, 2019, 09:05 AM
    knalex01

    Re: How to clean carbon on valves?

    Quote Originally Posted by Roman NJ View Post
    Since it is not in your signature, would you please specify Year and mileage of your truck. Some pictures of the build-up would be nice. I guess it is safe to assume that everyone with similar mileage will probably have more or less similar situation. No wonder Audi had decided to utilize set of regular injectors along with Direct ones at some point. I would imagine that would make engine even more complex but guessing for a reason.
    Just fixed sig, good idea. (I did have info in my profile though mileage doesn't show there)

    Mileage is 72K.

    And yeah I'm amazed at how bad the carbon coking is, it's not just a little, it's a LOT. I had thought my bad idle was due to timing wear, but now I'm thinking it's due to the valve coking.

    BTW, thanks for the walnut blasting idea. I now realize there is no way in hell a chemical cleaner is going to do the trick. So I just bought all the stuff to walnut blast my valves. It's actually pretty easy - you just buy a cheap abrasive blaster at Harbor Freight, walnut shell grains, and a "vacuum" attachment that sucks everything out as your blasting.

    Regarding the vacuum attachment, I couldn't find one built for just Range Rovers, so I bought a kit off ebay that has 10 different attachments. I suspect that one of the attachments in the kit will work perfectly, but worst case I will modify one of them a bit.

    I will post a full DIY once I do it.
  • May 19th, 2019, 03:39 PM
    Roman NJ

    Re: How to clean carbon on valves?

    Since it is not in your signature, would you please specify Year and mileage of your truck. Some pictures of the build-up would be nice. I guess it is safe to assume that everyone with similar mileage will probably have more or less similar situation. No wonder Audi had decided to utilize set of regular injectors along with Direct ones at some point. I would imagine that would make engine even more complex but guessing for a reason.
This thread has more than 15 replies. Click here to review the whole thread.

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •