[Elliot1126]

I was gonna do a walnut blast of my intake ports and i was originally gonna take off the valve cover but it was being more of a pain than i wanted to deal with at the time so i figured i would skip that if i could and just walnut blast without taking off the valve cover. My only problem would be knowing when the valves are closed and also if the walnut blast would ruin the valve cover runners.

[Master_Chase]

Originally Posted by Elliot1126

I was gonna do a walnut blast of my intake ports and i was originally gonna take off the valve cover but it was being more of a pain than i wanted to deal with at the time so i figured i would skip that if i could and just walnut blast without taking off the valve cover. My only problem would be knowing when the valves are closed and also if the walnut blast would ruin the valve cover runners.

My dad blasted his 335d without taking the valve cover off just used a borescope camera to watch the valves.

[RED-d]

There's a DIY in the "Sticky"

[335dlci]

Wouldn't trust jt.

[maryjane]

Not trying to be an ass or anything, but if you're asking these kinds of questions, you should probably take it to someone. You can do some pretty catastrophic damage if you mess up.

[Tomnavigator]

Elliot,
I walnut blasted my 335D without removing the valve covers. However, I think I am in the minority. I estimate that 3/4 of the people remove the valve covers for two reasons. First, the valve cover gaskets are known to leak when they get old and replacing them is a good idea. Second, removing the valve covers reduces the length of the inlet runners to the valves (and they curve) which makes cleaning the buildup off the valves easier. I was successful with my cleaning because I made my own blasting probes with 5/16 and 3/8 inch copper tubing. I just bent the tubing to match the curve of the inlet ports. I used an inspection camera to check effectiveness and repeated as needed until clean. The main reason I did not remove the valve covers was fear of getting walnut contamination in the engine. However, it appears most people do not have an issue with contamination.
Both methods work and give good results as long as you check your results with a camera and repeat the cleaning as needed.
I made scrapers from BBQ shiskabob skewers and scraped all the carbon I could before walnut blasting. I bought a harbor freight sand blaster and make my blast probes out of copper tubing. I used fine walnut shells and reused them after screening out the carbon particles. I have attached some pictures of my egr, throttle body and inlet ports. There is a picture of the carbon I removed from the EGR on a paper plate with my home made scrapers. All the carbon on the plate came off the EGR.
The inlet port runners in the pictures are 4, 5, and 6 cylinders which were the worst ones. I wasn't smart enough to take pictures of the after cleaning of the inlet ports because I just wanted to get done. However, they were completely clean.

[Elliot1126]

Thx for the advice everyone i ended up taking the valve cover off and replacing the gasket while i was at it. And i then realized my valves must have been recently cleaned by the previous owner because they we’re very very clean. So i just decided to skip the walnut blasting. In the process i broke one of the valve cover bolts also