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HOW TO: Clean your valves

55K views 48 replies 21 participants last post by  daztd 
#1 · (Edited)
Due to the nature of direct injection, these engines will accumilate a large amount of carbon build-up over time. The only way to remove it is manually scrubbing, or media blasting the valves. Using seafoam/engine cleaners/ect will not do anything measurable to this buildup, this cleaning is basic maintenance in order to keep your engine running at its best.

Do this every 40k miles, and I also recommend deleting the EGR valve, swapping your PCV valve, and installing an OCC kit at this time to keep the intake manifold clean
Guide to Preventative Maintenance and Modding

Links to info on DI and other DI cars, showing how common it is for the industry to clean:
Carbon Build Up Info
VW Golf
BMW
*Note: BMW/VW/COBB all offer valve cleaning at their dealerships, among other places- it is an industry standard to clean them

Why clean? Better performance (recovered flow), smoother idle, smoother driving, save money, and to learn about your car!



Here is the best method for cleaning your valves: before/after soaking/after a little blasting



Equipment needed: (noted below, with pics)
  • An air compressor setup
  • Media gun/abrasive gun (open/close valve-but not necessary)
  • Fine walnut media **Note: HF has a different categorization than other places for the grit on the media**
  • B12 -2 cans (1 could do, if you are tight on cash)
  • 1' section of clear hose from Home Depot - 1" ID, available by plumbing
  • A towel you can sacrifice
  • Two way fluid transfer pump
  • Masking tape
  • Safety glasses/gloves (IMPORTANT)
  • Camera- to brag once you are done

Brief Overview of procedure:
  1. Remove IM, followed @jbarone instructions (here)
  2. Ensure which 2 valves are TDC- top dead center/closed
  3. Soak those valves in B12 for at least 1 hour & cover other valves with masking tape
  4. Suck out majority of B12 using two-way fluid pump
  5. Air blast valve to remove remining B12, while using a towel around gun tip to catch carbon/B12 coming out (goggles/gloves on) (90psi for all air use)
  6. Blast valves with media in 2sec pulses for 30sec, vacuum on, repeat until happy
  7. Suck out media with small hose, then air blast for 10sec to remove anything else
  8. Tape over cleaned valves
  9. Proceed on other valves in same order (TDC/soak/suck/blast/clean)
  10. Photoshoot

TOTAL COST, without air compressor = only ~60 bucks, and you have 24.8/25 pounds of media left to help many others and clean again!

In order to achieve these results, the process goes as follows:

STEP 1
Soak 2 TDC-top dead center valves in B12 (maybe-substitute denatured alcohol/seafoam/methanol)
Top dead center is achevied by removing the passenger front wheel, then a little plastic guard which is held on by 3 plastic screw-you can't miss it, then you will see this:


The (14mm) tensioner pulley is on the left-turn this clockwise to loosen the tension on the belt before/after messing with the PS pump. You will need someone to remove the belt from the PS pump as you relieve the tension

The (21mm) crank pulley is on the right, turn clockwise to turn the engine, it will be at TDC when it gets toughest to turn (check valves are TDC by looking, then pouring some B12 in and see if it stays put)

**Note: Only 2 valves will be entirely TDC at a time. On mine, one valve was 90% closed, so take note for next time (ie- valves 2/4 and 1/3 are TDC grouped for me)

Open valve


Closed valve


**Note: I do recommend removing the belt from the power steering pump before turning the crank pulley (before tilting the PS pump to the side during the Intake Manifold removal is even better), but it is not needed

STEP 2
After soaking the TDC valves either overnight (prep night before), or for 1+ hours, use either your shop vac (if you wish to ruin the filter and spend time cleaning it-trust me on this) or a two way fluid transfer pump (Here: 5 bucks at HF) to suck out as much B12 as you can into a container

Now take your gun, wrap the towel around the tip. Now insert/jam it into the valve to AIR blast all the leftover B12 out (it will shoot out, so wrap the towel in layers to make it thicker, and apply pressure)
**Note: Always use safety goggles and some gloves


STEP 3
Now, apply the one foot section 1" clear ID tube from Home Depot ($2) into the valve runner, as in this picture:

**Note: I soaked one valve for only ~1hr and got the same results, but it took a whole 2-3 minutes longer to clean!

I drilled a hole just small enough for my gun tip to fit into, roughly 1" from the base of the tube, then I stuck the gun/hose into the valve runner and apply the vacuum cleaner/shop vac to the open end.
I blasted at 90psi-the gun max operating pressure (BMW instructions say 6 bar, which is 116 psi BMW Link)

Blasting was done in pulses of 2sec for about 30 seconds total, then the valves were nearly spotless! Of course, I kept going to make them shiny and pretty, but honestly, this can be done on all the valves in under 10min.

**Note: I turned the vacuum on periodically to suck up excess media, since the tube collects much of the media. Keeping a vacuum on a "low" setting throughout the blasting could also be done, but you will use more media, as noted below. I also held the gun sideways (hood-style) to avoid any jamming, which worked best.

Unlike the prior write ups, I used a gun from harbor freight which had an open/close valve for the media. This allowed me to only blast air, which cleans very well on its own. This also allowed me to use less than 1 hopper of media for ALL the valves (out of the 25 pounds I got from Harbor Freight). Blasting only air into the valve periodically in essence reuses the media which is laying down there; think of it as a balloon which you let loose in a box-it smacks into everything. Another great point of using this gun was the ability to air-clean the engine bay, since 100% of the media is never going to be contained.
Gun used:
Gun has standard 1/4" air hose fitting and was sealed at the threads using tephlon tape (standard air tool procedure according tpo the neighbor)

This is what my setup looks like, note the vacuum attached on the end:


STEP 4
After blasting was to my liking, I stuck a small plastic hose attached to my vacuum into the valve to suck up any excess, then I blasted the valve with AIR for 10sec to clean anything remaining out (although it would just burn off, walnut is combustable).

**Note: cover the finished/remaining valves with masking tape to avoid any richochet media going in. I also taped the gun's hopper closed since I was holding it at all angles


That's it guys, let me know if you want clarification on anything. As a sidenote, you could probably acheive very clean valves simply by using the air and soaking (as noted in this thread, post #15) Props to @timjs for inspiration on this project. I think B12 does an identical job to the Mazda Zoom Zoom Cleaner, possibly in a less concentrated form; but, nonetheless, it is just as effective for a fraction of the cost. Zoom Zoom Cleaner is originally designed for rotary engine cleaning, link to RX8 forum info

I used the liquid B12, since it is cheaper and the spray does nothing we need


Got clean valves yet?
 
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#34 ·
^^ Good point about the injector location but the fuel still collects moisture and the deposits still build on the injectors. I'm not sure on the "shut down" cycle order, but I'd guess the fuel is cut followed by ignition. Each time an engine stops those combustion gases, fuel and air mixture basically settle on everything and form a thin layer of deposit. Depending on which valves are open the deposits migrate into the intake track too. Point: you stand to gain more than you loose esp w/methanol in everything in the states these days.
 
#39 ·
Since my car is past 100k miles, I getting ready getting every thing I need to clean the valves to do it when the time the weather gets warm since I dont have a garage.

I how big should I get a the compressor that will be adequate for this job and that will also be good to other work on the car? Can a 3gl 100psi do the job or do I need something bigger?
 
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#40 ·
Subed too. I have 5gal 150psi pancake.
@TiGraySpeed6

I think the small ones should be fine. It just may take longer as the air volume is so small.
 
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#41 ·
This is a great way to clean your valves, but I did mine last before this was posted.

SO, that said, when getting a compressor for the garage, get the biggest one you can afford. If your wife isn't totally pissed off, it isn't big enough. Nobody was ever upset about having a good compressor, but many many have been frustrated by not having enough compressor.

Big tank so it'll blow for a while before running out of air & needing to cycle the engine, and an engine big enough to fill that big ass tank back up. Pancake is a great style for randomly firing a nail gun, but typically not up to the task of running a spray gun or a grinder, often not even up to running an impact gun.

At least $150 - 200 on the low end, at least 15 - 20 gallon, at least 2.5 - 5 hp.

If you don't have anyplace to put a good compressor, then find somebody who has one, or just use denatured alcohol instead. There's just no sense in wasting $100 on a crap compressor that does nothing well besides waste $100 of your hard earned money
 
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#44 · (Edited)
Unfurtunatelly on my case I dont have space to store it, so I will have to find some one with a good one or find another alternative

If you don't have anyplace to put a good compressor, then find somebody who has one, or just use denatured alcohol instead.
Denature alcohol to clean the valve will I use that after using B12, instead of the walnut media? and will I just let seat there an let it burn off or do I still need to extract it with the 2way pump?
 
#42 ·
Easy enough. Time to go shopping for a big 50 gallon. To hell with the wife!
 
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#45 ·
The tools I used, along with a battery drill. Brass bristle brush in the battery drill, fill with chem of your choics & let soak, run the brush down in there, then suck out the nasty with the shop vac. easy peasy.




Tube attached to shop vac to extract the chems and any debris



DA for reference, can use either DA or B12, both work well to soften the carbon deposits on the valves. I just used DA, others have just used B12. No need to use both- just get what's available & go with it. Price is comparable.




What was left in the shop vac after the DA evaporated - Yikes, glad it's not on my valves anymore!





Time involved,rough ballpark, just off the top of my head & probably missing stuff-
experienced with this platform, has removed the IM before and has all tools & chemicals at hand & ready to go. No distractions, no beer drinking etc....

5-6 hours if they're in bad shape.
And add 10-20 min for cleaning the IM
optional - add another 30-60 for removing the VCTS

Mechanic who's never done it before, ~8-10 hours.


30 min - tear down
first three cyls-
20 min - first soak
20 min - first clean
20 min - second soak
20 min - second clean
20 min - third soak
20 min - third clean
30 min - picking & scraping
10 min - change open valves to different cylinder
remaining cylinder-
20 min - first soak
5 min - first clean
20 min - second soak
5 min - second clean
20 min - third soak
5 min - third clean
10 min - picking & scraping
30 min - reassembly
---------------------------
+/- 5 hours

It's not hard, but it's the very definition of a pain in the ass...


.
 
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#46 ·
Thanks Tigray! by your break down I will probably be some where in the 8-10 hours since that will be first time touching the car besides regular oil change.. . I will should be able do this some time in the Spring since I dont have a garage that I can work on during the winter. So I will make sure to get all the tools, chemicals, and stuff needed for the job way ahead of time.

I will probably also replace the pcv and do the EGR delete and add a catch can while at ti
 
#47 ·
For anybody doing this job, and regardless of how you choose to do it (better results with the media blaster, but either work & anything is better than not doing it at all), here are a number of things to consider-

If you've never removed the intake manifold (IM) before, I encourage doing this in advance to look around & get an idea of what's involved. The first time you remove the IM you can plan a few hours as you learn where all the bolts are and the best way to deal with the power steering pump.

I'd encourage taking the opportunity to replace the OEM IM gasket with a Thermal Insulating Gasket (TIG) between the IM and block. If you live up north and still run coolant through the throttle body, get the TIG for between the TB & IM as well. If you live down south, just do a TB coolant bypass instead- much better results.

The IM gaskets can be re-used, but the TIG's work remarkably well & are a worthy improvement for the small cost- you'll see your BAT's drop several degrees.

Also, if you've not done it yet, you do want to replace your PCV valve while you've got the IM off. You just can't do it without removing the IM, so if you're there, do it. The only hard part is getting the retainer ring off. Replacement valves, and the retainer ring, can both be found at the dealer parts counter.



Adding Oil Catch Can's (OCC) is strongly encouraged- The PCV system routes from the PCV to the IM, using vacuum from the IM to pull pressure out of the engine, which includes oil & other contaminates. Routing that mess through an OCC means the nasty stays in the OCC and not into your IM and then onto your valves. I drain several ounces of oily nasty slime out of mine at every oil change. Nasty crap that would be sent back into the engine...

As an extra help, you can also consider an EGR delete that will also help block off nasty shit from your exhaust from being redirected back to the IM. For this one tho you may need to take into account your local laws on vehicle inspection.
 
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#49 ·
I didn't, but bought one just in case it was an issue.
 
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