I have a 2007 Cadillac CTS with the 3.6L. A few months ago I had a problem where my car would crank but wouldn’t start and I had to have it towed. The shop said the reason it wouldn’t start was because the valves had lots of carbon buildup, which according to the mechanic was a known problem with this engine. I’m not sure what they did to get it started, but my bill included a new intake manifold gasket (which might be unrelated, they changed the spark plugs too) and “Carbon Cleaner, $24.99”.
Now the car won’t start again and has similar symptoms. I’m stuck at home anyway and have all the tools I need so I want to see if I can avoid a repair bill. Does anyone have any idea what this cleaner might be and how I could get my car started? I know with sea foam you have to have the engine running. Is it possible they just cranked the engine and sprayed the cleaner in the intake and let it break everything down? Would taking off the valve covers and trying to clean the top of the valves do any good? I’ve already taken the spark plugs out and confirmed there was some carbon buildup, but I was able to clean it off.