Seafoam in the oil...safe?
 

It was suggested in another thread that I try Seafoam, which I have in the vacuum line, and gas tank. I haven't added it to my oil yet. I have been reading various posts on various sites, and there seems to be some concerns about adding Seafoam to your oil. Has anyone had any issues with this? My car is a 2000 Honda Civic VP (dx engine) with 183,000 miles. I get regular oil changes. My thinking is to add the Seafoam to my oil on Friday, and I am getting my oil changed Saturday morning. Or should I skip this step?

My only knowledge of seafoam is that it is recommended you change the oil within 500 miles if you do use it in the crankcase. And quite possibly the sparkplugs if you use it in the fuel tank. It's not supposed to stay in the oil, it's to clean out any buildup so changing the oil only seems logical. The sparkplugs could be a concern if it starts missing after you use it in the fuel tank, it could foul the plugs.

yea you should be ok if you put it in before work and then change the oil sat.

From experience, you want to go through a couple warm up cycles (20+ miles) if you expect the sea foam to do anything.

An alternative to this is to use a solvent, thoroughly drain the oil from the crankcase, install the solvent, and manually work the oil pump for 10 seconds, repeating 10 second bursts every 5 minutes or so.

If you drain the solvent and it comes out cleanish, put in some cheap oil, then flush the block with itto remove any leftover solvent. Add your new oil and filter, and your good to go.

I will get a few warmup cycles in. I was reading that you want to put it in while the enhine is cool as not to shock stuff...That didn't make sense as when I get oil changes, my car is using warmed from having driven to the shop and the oil being added is cold...
But I will add the Seafoam tomorrow morning. Drive to work (13 miles). Drive at lunch (1 mile). Drive home (13 miles). Drive to karate (2 miles). Drive home (2 miles. Then drive to the shop for the oil change (20 miles). So that should give it some time to work.

personally, when a car starts getting a higher amount of miles, and never had that kind of solvent cleaning before, it's best not to do it now.

Some of the buildup in the motor might actually be beneficial to the longevity of your oil pressure and bearing surfaces. If you effectively clean out the motor, you send larger bits of debris thru the system and also increase the working clearances on the bearing journals, which may cause an oil pressure drop after such a cleaning.

I vote don't do it.

Zonker's on point here, and the Seafoam bottle itself states it's "not to be used on vehicles with over 150,000 miles."

However, it's not definitive. Here's a link I've bookmarked with compression tests before and after seafoaming a civic

Seafoam on high mileage engine - Compression results - Honda-Tech

at 198,000 miles, I'm hesitant too!

You need to ask why you want to do this.

I've used Seafoam in the crankcase to free up a sticky lifter, and it worked. But to do it just for the hell of it? I think it's OK but what is it going to do?

I haven't done it. I just figured I would do it to clean out the gunk in there, and maybe make my engine run a little better and keep running better. I am hoping to get a lot more miles out of this car. I have been told these newer Honda engines can get up to 500,000 miles.

Look under the oil fill cap and down into the valve cover. Change the oil and look at the plug, the drain oil, and the filter. A lack of condensation (milky white) and/or gritty sediment pretty much means all is OK in there.