Seafoam and Synthetic

[kimokalihi]

I am going to change the oil in my 90 Legacy L Wagon auto and I want to run some seafoam through it. I just put a bottle of STP fuel system cleaner in it today so should I stick the seafoam in it for the next tank or don't bother?

 

Anyways, I'm going to put the seafoam through the PCV or the vacuum line, whatever and also in the oil before I change it. Drive it for a couple days and then change the oil probably on friday.

 

I'm considering synthetic oil as well. Should I replace the oil with synthetic right after putting the seafoam in or should I put regular oil in it one more time to make sure I get all that crap out of there before I put expensive oil in it?

 

I've never used synthetic so I was wondering which brand, maybe how much to expect$$$, anything else that I should know before I do this. I'd really like to be able to rely on this car and I know it's been neglected by the previous owner, I just don't know how bad. I'll also be replacing the knock sensor on friday. It seems to run good, except it's not very responsive and especially not since I got a knock sensor code a couple weeks ago and then it went off.

[NoahDL88]

First off, STP products are useless, and won't do anything but empty your wallet.

 

Seafoam is great, i wouldn't worry about using it in your oil unless its ticking, but sucking in a bottle through a vacume line is great, i just pulled a motor with 250k on it, and with a seafoam treatment about 20k ago it was brand new clean in the intake track.

 

As far as switching to synthetic, its mucho spendy, 4-7 bucks a quart, but you can extend your oil change intervals if you make sure to keep the level up above the fill mark. a word of caution however, it could remove the varnish and buildup that is keeping your seals from leaking, so it could start leaking oil from various locations, although that is not terribly common, it is somthing to think about.

[Setright]

What he said.

 

Go for a semi-synth. Shell or Castrol will do nicely.

[scorch]

I'm considering synthetic oil as well. Should I replace the oil with synthetic right after putting the seafoam in or should I put regular oil in it one more time to make sure I get all that crap out of there before I put expensive oil in it?

 

It shouldn't matter. But then, I wouldn't bother with the seafoam in the first place. It's not going to accomplish anything that the regular detergents in the oil will do anyway, especially if you go with a good synthetic. You're basically buying snake oil for your car, you know that don't you?....

 

I've never used synthetic so I was wondering which brand, maybe how much to expect$$$, anything else that I should know before I do this.

 

It shouldn't matter which brand. They are all extremely high quality. You hear lots of scuttlebutt about leaky seals after you switch to synth, but that has not been my experience. Imagine being concerned that your oil NOT get rid of gunk in your engine! To the contrary, if it's so dirty that it's keeping leaks from happening, you want something to clean your engine ASAP, and just deal with the leaks when/if they happen. But again, the concern is really overblown to begin with.

 

The one thing that you need to be careful of, especially if you decide to go with an extended service period with the synth oil, is that you get the very best oil filter that money can buy. No sense in sinking money into expensive oil and then trying to keep it clean with a cheapo Fram filter.

 

Personally I'm on the fence about the synth vs. dino question. If you intend on driving the car till the doors fall off, you should switch to synth because it will indeed extend the life of the engine. But if you're going to sell it at 200K, I don't see any benefit to it. Because if that's the case, you're basically shelling out a lot more for oil for the benefit of the person you'd be selling the car to, the person who WILL be driving it till the doors fall off. It's certainly not going to effect the drivability or dependability of the car. But I use them because I'm really anal about getting the best stuff for my cars (I just wish I had the same attitude about my own body).

 

On the other hand, for the fluids that have a long service period and don't get filtered, such as the diff and the manual transmission, I think using synthetic in those applications is a no-brainer. Do it.

[kimokalihi]

Alright, well I do plan on driving this car quite a bit. Especially in the winter when I go snowboarding. That's like 4 hour round trip each time and I go every weekend. That's not including driving to work and college.

 

So that said, which seals usually go out(if they go out)and how difficult is it to replace them? The thing is, if it's going to be too time consuming I don't think I'll put it in the oil because I really have almost no time to do anything right now.

 

On the other hand, I think I need to check some seals anyways because there's oil on the bottom of the engine and it looks like it's either coming from the valve covers or the front of the engine. I never have to put any oil in it so it must be a very slow leak. This car needs some help and I wish I had more time to nurture it.

[Andyjo]

i switched to synth a while ago... and got a nasty leak in my valve cover gasket... switched back to good ol' 'real' oil and the leak stoped again

[kimokalihi]

Put the seafoam in today via the PCV vavle. I noticed that the hose and the metal connector that it screws into were all gunked up with dried black stuff. It was pretty bad. I decided it would be a good idea to remove these and clean them out before pouring the seafoam in and letting all that crap run into my engine.

 

I began to scrape it out of the hose with a screw driver and it was coming out like a chimney! Jeez. Once I got all I could out, I put the hose back onto the threaded(valve? but not back into the manifold!)and poured some seafoam in it and shook it around in there. Then I poured it out and it was really nasty. Then I blew it all out with an air hose.

 

I replaced the stuff and let the car warm up again(I had it all warm and ready to go when I pulled the hose off and realized how gross it was)and then I began to very slowly pour it into the hose. It died. Almost immediately. I had to give it like 2000 RPM the whole time to keep it running and it put out A LOT of smoke lol. Some people said it's a smoke show, others said not much happened. When I did it, it was a whole hell of a lot of smoke. I drove it probably 2 miles(after letting sit for 10 minutes)before it quit smoking.

 

 

 

 

 

Conclusion:

 

I think it runs a little smoother and quieter and a LITTLE bit more responsive. I'm pleased with the results, even though they're not very noticable. For 7 bucks it was worth it for sure. The thing is, it never ran bad. It was just a bit hesitant. I think I need to drive it more in the city to see if it really helped. The "spirited drive" I took it on was like 50-80mph back country roads so it was hard to tell if it's still hesitating because that happens mostly from stop and go stuff.

 

I will not be putting it in the oil, although I'd like to. I don't want to risk oil leakage. I just don't have time to deal with that at the moment. But I'll put the other half of the can in the tank when I fill it up. Thanks for everything.