Why not leave it in? Because that's not the intent of the product. It's a cleanser. Wouldn't you agree that you don't leave any detergent on anything forever?
Comparing this product to another should be apples to apples. The Z-max products are singularly specific to fuel, engine and transmission (3 different products) and are sold as lubricants, not cleaners. Not a good comparison.
Just not sure what prompted you to take this position on Seafoam in the crank case - did you have a bad experience with it? Or know anybody that has?
I mean the REAL reason you don't leave it in. You don't leave it in because it would destroy the rubber seals and the interact with oil that's in the crank case, effectively removing (or best case reducing) the lubrication value of the oil. There are detergents in oil that are safe long term.
I was comparing the reputation and widespread use of Seafoam to that of Z-Max. ie, just because thousands of people use it and the manufacturer says it's great, doesn't mean it's harmless. It's a product, for sale, like any other. How about this for a comparison; Thousands of people smoke crack, the manufacturers say its great, and most people don't die from it...
Don't get me wrong, I think it's great stuff (Seafoam, not crack) and I totally use it in my intake and gas tank. I even have two cans in my shed at this very moment. I was recently doing some research before I planned to use it in the oil for the first time, when I happened upon a very insightful review by a dude whom I thought was pretty smart. I'll try to find it for you... Anyway, that's what prompted me to investigate it further and I just can't find any logical reason to use it in the crank case. The reasons not to use it there are fairly obvious if you think about it: Possible damage, probably no help, no better than frequent oil changes, more often than not no "sludge" to begin with, etc...
Ok, I'm looking for "proof" starting.........now.
EDIT: Oh yeah, and pertaining to your question below about the plug fouling. It's because Seafoam contains a significant amount of pale oil, which is also why it smokes when added to the intake.
---------- Post added at 11:18 PM ---------- Previous post was at 09:21 PM ----------
Ok, I found the thread I was talking about above. This is what made me question the idea of putting Seafoam in with the oil. My subsequent research on this topic was to verify the guy's claims (which I found to be true) and to look into the specific ingredients. This thread is a great read for anyone thinking about using Seafoam. Interesting regardless...
Thread:
http://audiforums.com/forum/showthread.php?t=92596&highlight=seafoam
Some highlights...
Ingredients in Seafoam:
1 PALE OIL 4229 40-60%
2 NAPHTHA 20 25-35%
3 IPA 125 10-20%
Point:
"...yes it can help dislodge sludge, at the expense of lubrication. but if you actually have a sludge problem, removing it is not addressing the root cause..."
Addressing the claims on the Seafoam website. The thread is from 2008, some of the info on the Seafoam website has changed since:
"Ah what the hell, i decided to see what the sea foam company has to say about their product. What exactly do they claim it does? What does common sense and logic say when applied to their claims?
http://www.seafoamsales.com/motorTuneUpConsumer.htm
1.When your vehicle has a rough idle, hesitates, stalls, pings or has an after run problem – this is often due to carbon buildup.
-Yea, and that traffic jam in the morning is due to carbon buildup
View attachment 171947 There are so many possible reasons for these symptoms, carbon being one of them. Pouring additives in oil/gas will not address the root cause of these issues even if it removed the carbon.
2.When your vehicle's fuel injectors need cleaning – this is often due to residue left on injectors from poor burning fuels and contaminants.
-So how is pouring low quality oil and rubbing alcohol in your gas going to clean it out?
3.When moisture needs to be removed from fuels or an anti gel or de-icer is needed – these conditions are due to condensation in the fuel tank and extreme cold weather creating gas line freeze or diesel fuel gelling.
-Im sorry but moisture can not be removed from fuel. It physically can not mix with fuel. It can get into your gas tank or lines, settling at the bottom. The rubbing alcohol can bond with both gas and water getting some of the water pumped out with the fuel. the real solution is to clean and decontaminate the tank and lines.
4.When there is moisture detected in the oil – this problem is due mostly to poor ventilation and condensation. Sometimes, however, there is a bad head gasket, cracked head or block that must be replaced.
-See above. oil and water do not mix. water would collect at the bottom of the crank case, making it fairly easy to remove, unless you have a massive amount from a blown head gasket. real solution (unless you have a $500 car): disassemble, hot tank. Adding solvent and low quality oil will not get water out of your motor.
5.When valve lifter noise is apparent or piston rings seem to be sticking – this is often due to dirty and gummed up oil passages, varnished lifters and buildup of gum, varnish and carbon in the piston ring areas.
-Same as #1, if you have these problems the root cause needs to be addressed, or you will blow your motor eventually. Adding solvent to oil and destroying its ability to lubricate wont help.
..."
