Walnut blasting dirty intake valves

[Kenny Camaro]

Well, April Fools day is when I pull the cover off the 2013 RS CRT Camaro. This year I have a lot of items to check off the list before getting her back on the road. First on the list is to walnut blast my intake valves. I have 26,600 miles on her and she has not had the valves blasted until today. I did do a solvent cleaning at 21,000 miles. I installed my catch can at about 24,000. Here is some pics of the valves prior to the cleaning.

[Kenny Camaro]

Looks like as part of the April fools day festivities, my pics are coming up upside down. Well, that's something. Here's some shots after the cleaning. Maybe they'll be rightside up, or maybe not. Let's find out.

[Kenny Camaro]

Hey, alright! The pics came out rightside up. As you can see, the the valve were coked up heavily and and needed a cleaning. The walnut blasting did a great job!! Better than I expected. Some more of the back story. I've used Mobil 1 since my third oil change. I changed my oil at 1,000 miles from the factory oil to the GM Dexos semisynthetic oil at the dealership. This was the complimentary first oil change that came with buying the car. At 3,000 miles, I changed the oil over to Mobil 1. I have changed the oil at 5,000 miles or in the spring as part of getting the car out for the season ever since.

[Jazzzed]

Looks good. You had quite a bit of coking there for that amount of mileage. Did you put your JacFab spacer on too?

[Lil' Nasty]

Looks great, mind posting what tools you used and procedure?

[1Coopgt]

Did you do this your self or take it some where? If you did this your self did you rent the equipment ?

[Kenny Camaro]

Originally Posted by Jazzzed

Looks good. You had quite a bit of coking there for that amount of mileage. Did you put your JacFab spacer on too?

The extendolater will be going on when I finish the other projects I'm doing at the same time. I'm also porting the in take manifold my self and porting my 80 mm TB. I believe I will be the first one to port the Overkill Throttlebody.

[Kenny Camaro]

Originally Posted by Jazzzed

Looks good. You had quite a bit of coking there for that amount of mileage. Did you put your JacFab spacer on too?

Originally Posted by Lil' Nasty

Looks great, mind posting what tools you used and procedure?

I went to harbor freight and bought coarse crushed walnut shells and a one liter suction media blast gun. I followed the instructions for the Jacfab spacers for removing the intake manifold. You can download the instructions from Jacfab website. Used some two inch masking tape to cover the valve openings not being blasted. Make sure you blast the closed valves! You'll need to turn the engine over to close the open ones. I used a shop vac to suck up the media while blasting the valves. The walnut media made short work of the dirty valves. You will need an air compressor too.
I used coarse, but medium will work better with the gun and does the job on the build up just fine!

[Kenny Camaro]

Originally Posted by 1Coopgt

Did you do this your self or take it some where? If you did this your self did you rent the equipment ?

I did it myself. I got the air compressor for Christmas. The coarse walnut media was 25 dollars at harbor freight for 25 pounds, which I believe will last a lifetime! That media blast gun was also 25 bucks ata harbor freight. So fifty bucks I got it done! Someone in the general section recently had his valve cleaned and had a dyno before and after to see what the cleaning did for an increase in rwhp. He did three pulls ,did the cleaning,then three more pulls. The charged him 500 bucks. So it's usually 3pulls for 100$. So, 200 for the dynos and three hundred for the cleaning, would be my guess. He got 10-12 rwhp gain across the three pulls. Hopefully I will get similar results for $50.

[BluedEvil21]

Looks good!

[1Coopgt]

Originally Posted by Kenny Camaro

I did it myself. I got the air compressor for Christmas. The coarse walnut media was 25 dollars at harbor freight for 25 pounds, which I believe will last a lifetime! That media blast gun was also 25 bucks ata harbor freight. So fifty bucks I got it done! Someone in the general section recently had his valve cleaned and had a dyno before and after to see what the cleaning did for an increase in rwhp. He did three pulls ,did the cleaning,then three more pulls. The charged him 500 bucks. So it's usually 3pulls for 100$. So, 200 for the dynos and three hundred for the cleaning, would be my guess. He got 10-12 rwhp gain across the three pulls. Hopefully I will get similar results for $50.

Awesome thanks for the info.

[Kenny Camaro]

Here's a pic of the blast gun I got from harbor freight. Make sure you get this one and not the gravity feed gun, as the gravity feed gun will not work. Looks like the pics are upside down again. Don't know why they are flipping.

[Elite Engineering]

Nice job Kenny!!

Yours are about correct to what we usually see in our testing and inspection of a GDI engine with similar miles. The M1 oil you use should result in less severity in the future as long as your using a good catchcan set-up.


We have been showing this for several years now with our commitment to educating vs just "selling". You should notice immediate gains in power, smooth running, less hesitation, and of course better fuel economy. To be aware, the time running with the coking has most likely contributed to wear of the valve guides as this hard abrasive material is drawn into the guides with each cycle of the valves, but hopefully not severe.


Thanks for sharing, and ALL GDI owners should be aware of this, especially the Gen6 owners as both the V8 and V6 are now GDI and the V6 GM deleted the "Positive" function of the PCV system and now most of the contaminates that used to be evacuated are now left to settle and mix with the engine oil increasing wear.

[Coleroad]

I rotated and enhanced one of your before pictures.