A seafoam use that makes no sense but worked

Post by **jtp** » 08 Dec 2017, 21:20

I work with an older guy who has a v70 in the 98-00 range like me. About a month ago he stopped driving it into work and told me the car was burning so much oil he had to get rid of it and we started talking about what parts I'd buy off of him before he junked the car.

Then one day the car shows up again, he took it to a shop where they removed the plugs to put seafoam directly on top of the pistons and let them soak for 24 hours, and he said this cured the oil burning.

I can't figure out why on earth that would work. If oil burns by slipping past cylinder rings wouldn't cleaning that whole area maybe even increase the clearance between the rings and the cylinder wall, making for more oil consumption???

Sorry for the long story, he drives the car regularly again though so it must have worked somehow and this has just been bugging me I don't understand it, wondered if you guys had some insight.

Post by **wizechatmgr** » 08 Dec 2017, 21:26

Sounds like he had some stuck rings.

Post by **scot850** » 08 Dec 2017, 21:34

+1 on that. The car had a build up of carbon on the piston rings that probably stuck and allowed oil to bypass causing the smoking. The Seafoam broke down the carbon and freed off the rings to get back to their work. Smart garage recognising this issue and how to fix it. Might also work with the famous lawnmower syndrome.

Neil.

Post by **jtp** » 09 Dec 2017, 09:48

Nice, makes sense. I dont think he understood why it worked either so Ill let him know

Post by **rspi** » 09 Dec 2017, 10:29

My guess is that the Seafoam leaked past the pistons and got into the oil pan. I have no idea how that happened unless they found a leaking seal somewhere.

I have never seen a stuck ring in a car engine yet.

Post by **scot850** » 09 Dec 2017, 11:14

I have and it cost me an engine re-build on a 760 turbo. Dealer said it was a head gasket, needless to say they were wrong!

Neil.

Post by **precopster** » 09 Dec 2017, 12:02

That's the whole premise behind Seafoam increasing cylinder pressure and psi numbers after use. We've seen it dozens of times here on MVS so if it works on compression rings it will do the same on oil control rings.

It un-sticks partially stuck rings that have too much carbon working against them preventing full return to their extended position.

Post by **ZionXIX** » 09 Dec 2017, 12:37

So if someone wanted to try this to see if there is any restoration of performance, what would be the proper procedure?
For instance, How much to put into each cylinder?
How long to let it sit?
If there is a substantial amount remaining in the cylinder, should it be extracted before starting?
Should the engine be warm to begin?
Should the oil be changed before or after the first start up?

I have had low compression in one or more cylinders with a lot of blow-by, I'm wondering if this could be an easy fix to try.

Post by **precopster** » 09 Dec 2017, 12:49

A couple of hours of soak time and replace oil after letting the smoke clear (there will be a lot of smoke).

Some folk use a vacuum hose on intake as a means of input while it's running which is what directions on bottle suggest.

I'd be tempted to turn the engine by hand a little during soak time to help get it past the first set of rings.

Post by **JimBee** » 09 Dec 2017, 13:50

Agreed on turning the engine by hand, if only to be sure you don't hydrolock it and bend a rod.
I ran half a can of Seafoam in my 93 for a complete oil change cycle (~ 2500 miles). The oil was black when I drained it and the engine now passes the glove test.
I discovered that I've got a couple of leaky camshaft seals, though. Not sure if they're still leaking, but they had been, so I'm watching them.
Carbon can build up in the piston grooves, but also bakes into the cylinder walls, which can allow compression and oil to slip past.