Reading the comments from our fail blog; we discovered that many people still use Sea Foam with success in cleaning carbony gunk off the innards of their internal combustion engines. We admit that we know about Sea Foam and know it’s been around longer than we’ve been wasting oxygen on this planet. Heck, even our Grandpa used this stuff every spring in the fuel system of his outboard motor on his fishing boat. It would turn the glue in the gas tank back into gas and make the old Evinrude smoke a little less.
But first, we wanted to know a little more about Sea Foam so we perused their literature on the their website. We discovered that it is 100% petroleum based product which surprised us because the stuff smells like a combo of kerosene and moonshine. The short version is that Sea Foam converts carbon back to oil from which carbon buildup came from in your engine. So, Sea Foam will melt carbon back into oil. Great!! Just what we needed. If Sea Foam works as advertised, the mounds of carbon buildup in our 350 will be squeaky clean by sun down.
We ran down to local parts store and paid $10 for a bottle of this stuff. It’s also available in gallon and 55 gallon drum sizes. According to the instructions on the bottle, Sea Foam can be used in the fuel system and in the crankcase. Adding to the fuel will clean out the gummed up fuel lines, carbs and injectors. Adding to the crankcase will clean out the carbon build up inside the engine. We are going to be adding into the engine while it’s running as per the instructions.
The instructions say to slowly pour Sea Foam into a vacuum line so it will be sucked into the combustion chambers while the engine is running. That vacuum port also has to be located so that when Sea Foam is sucked into the engine it will go evenly into all the cylinders. So first we needed to figure out how to pour it into a vacuum line. In this case, we thought it best to go with a bigger vacuum port, like the 3/8th’s line from the pcv or the brake booster. We chose the pcv port on the front of our Edelbrock carb. We got our cheap funnel with the corrugated tube we used in our last installment and found it fit the port tightly enough to seal it. We also discovered that the funnel whistled loudly with the engine running.
We bumped up the idle speed a tad, but it wasn’t necessary as the idle went up because of the vacuum leak we caused. Holding the funnel straight up worked the best for getting the Sea Foam to suck into the running engine. The directions say to pour SLOWLY about one third of the bottle into the engine with it’s running. That’s what we did.
While pouring the Sea Foam into the engine we noticed a few unusual things happening. First, the engine started running hotter than normal. The air being pulled through the radiator got noticeably hotter as we were pouring. Also, smoke started coming out of the air breather on the valve cover. Finally, we had four three foot long trails of carbon on the driveway behind the car. We’re still not sure how we had four trails as we only have two tailpipes. But, carbon being spit out of tailpipes means it’s being cleaned out of somewhere.
After pouring one third of the bottle into the funnel, the instructions say to shut off the engine for five minutes. Then, we restarted the car and goosed the gas a couple of times to blow out the cylinders of loose carbon. Boy, did the carbon blow out. Our four trails of carbon on the driveway got real black and sutty. The engine sounded like it was breathing better, so we’re sure whatever Sea Foam did, it was an improvement.
One other interesting thing of note was happening during this excercise. Our Monte’s front seal was leaking oil pretty badly. At first, we thought this might have been the cause of the oil going missing from our engine, but realized if the car had been leaking oil this badly all this time, we’d have a pretty good size lake of oil on the driveway under the car by now. In any case, we got out the RTV and slathered it all over the front seal to keep it from leaking any more.