Hi, I have a 96 Blazer fairly well maintained with close to 300k on it. I've been meaning to seafoam it using the vacuum line method with only 1/2 a can and doing a oil change after the smoke show. I've already cleaned a good deal of carbon off the throttlebody and cleaned the egr & iac. I noticed a thick layer of carbon or oil and dirt build up in one of the two ports leading to the egr when I had the egr removed. (not sure if the seafoam goes through this area)

In short, using the vacuume line method- is there a risk of dislodging anything to the point of causing engine leaks where their shouldn't be any in a high mileage vehicle? Someone else suggested on a different forum to do a compression test on the cylinders and if the compression is lower than 140, then you probably shouldn't seafoam. but this guy put seafoam in the crankcase, gas, and vacuum line. Thanks.

 

Seafoam in the oil would serve to clean the junk out of the rings as well just maybe not as fast as it would through the combustion chamber. If your truck is running fairly well, I'm not sure I would do it. If it did cause problems, it was just uncovering the inevitable.

 

Thanks Kyle, was wondering if Auto Rx has the same kind of effect as the seafoam in cleaning the junk out of the rings?

I was already running Auto Rx in the oil and I've gone 3000 miles now. Originally I was going to Seafoam before changing the oil with the Auto Rx treatment, but if the Auto Rx is already doing the job that the seafoam would do- then that would reinforce my decision not to use Seafoam before I do the rinse phase of the Auto Rx. Was I going overkill?

 

Most of the treatments available clean up the internals of the engine. Auto Rx is a leave in treatment whereas seafoam really isn't. If you were to put seafoam in the oil, you would want to do it 200-300 miles before your scheduled change and then dump it. It doesn't lubricate as well the leave in stuff does.

It really is a crap shot as far as whether or not anything bad will happen.

 

id just run it through the intake. I wouldn't pour it into the crankcase. If you had any bad leaks that crud was plugging up, you'd have more of a chance of problems pouring it into the oil. Just give the valves a good cleaning through the intake. I know some will still get in it,but not as much as dumping it into the oil.

 

Actually according to Seafoams website you can leave it in your oil until your next oil change no matter how many miles you have left. All they mention is that it will cause your oil to get dirty quicker which I take as changing your oil in half the miles you normally would.

 

I heard puting seafoam in the vac line only gets the back two pistons. Would it be better to put it in the PCV?