Does anyone know how to clean the valves to a bonneville gxp. I know there'* additives you can just throw in the gas tank but, I want to give them a good cleaning? I know you can have sea foam siphoned into one of the vacuum hoses that connects to the valve cover. Anybody have more info or possibly know which hose to have the sea foam siphoned from? Thanks!

Most people use the brake booster vac hose to siphon Seafoam. Sometimes it takes 2 people to do it because of the major vacuum leak it causes. (one person has to feather the throttle)

Aside from that, no real reason to clean them. Your probably best to wait until the head gaskets need replacing. The Northstars are troublemakers to blowing headgaskets.

Running a cleaner through the intake unmetered, runs the risk of hydrolocking the engine. Honestly Id have a gm dealer do the cleaning. It would cost more but at least it would be done correctly without the risk of hydrolocking the engine. Our shop uses Bg products and their intake cleaner does wonders compared to other brands.

I just use a well designed/engineered product called Techron Concentrate Plus. Avail at Wallmart.

I add 2 bottles to 94 octane fuel and take the car out for a good hwy run for a few hundred miles around 70mph where possible.
Then she purrs like a kitten....
I personally dont believe such a strong cleaner like Sea Foam is necessary in most instances.

seafoam works well, its going to do the valves if you put it in the gas tank. i put half a can in the oil on the yukon i got when it was knocking for the 4-500 up too and oil change and that works pretty good too.

It'* been my experience, that those products are good for preventive maintenance.......but if you get to the point where the valves are really gummed up, the horse is out of the barn....

i dont think you are just done. there are different levels of needing cleaned. the vortecs seem to be real dirty for some reason. i have heard of people who have single cyl misfire codes due to valve carbon build up and still clean it without taking the heads off. on the fsc forum there were a few guys that used MOPAR foaming cleaner dumped into the cylinders overnight and that brought it back

The reason I want to give them a cleaning is that I could hear like a clacking noise coming from the motor. Nothing terrible but it is noticeable to driver that drives it everyday. What do u guys think?

injectors click, would have to see if its more than normal. unless you are talking like lifter chatter