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Seafoam Spray Upper Engine Cleaner

5K views 28 replies 9 participants last post by  1997ThunderbirdLXV6 
#1 · (Edited)
Even though my 3.8 (naturally aspirated) only has about 40.000 miles on it, it is 25 years old. So I figured it can't hurt to try some cleaners.

After watching several "Chrisfix" videos, I decided to use Seafoam Spray. For those unfamiliar with it, it's the one that uses a tiny hose which is routed directly towards the throttle plate.

I followed the instructions to the letter, and here's what surprised me: all of the videos on this subject show dense, white smoke from the exhaust. In my case, the smoke was white, but it was very light during the injection of the product, definitely not thick clouds of smoke. During the subsequent drive, there was hardly any smoke.

:unsure: ...again, I followed the instructions exactly. So why hardly any smoke?

As to the results, I actually do feel an immediate improvement in smoothness. My car always (i.e., in two months of ownership) had a somewhat rumbly idle; that seems totally smoothed out now. Unless I'm imagining things.



 
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#3 ·
Well I've used the seafoam with the straw many times. It doesn't smoke that much in my experience. If you want to see the smoke, then get the bottle of regular seafoam and let it suck into the intake with a vacuum hose on the engine. You'll get more smoke for sure.
 
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#5 ·
A proper seafoam treatment fogs the whole neighborhood, on a 100k mile 4.6, anyway. :)
 
#7 ·
The first time I did Lazarus, my neighbor came running with a fire extinguisher, I told him "seafoam", and he knew instantly what I meant. I love thus place. :) He's a Chevy guy, and built some nice trucks.
 
#8 ·
But the old way of having it suck into a vacuum hose is a little dangerous. Go too aggressive and you could hydrolock the motor. I've had the motor make a pinging/knocking sound as it stalled. Have not done it since.

Just go WOT for 5-6 seconds at least a couple times every 200 miles. These engines loaf along at 1500-2000 RPM normally, they need to be worked a little harder to clear the carbon out.

Al
 
#11 ·
I love Seafoam. I have used it on every used car I have owned.
I have used it in the spray form and the liquid form to clean parts and as an engine treatment. It can be added to the fuel or oil, but I have never put it in the oil.

The key I found after a couple unsatisfactory treatments (little smoke) was heat sinking the intake manifold.
Use it as directed, but make sure the engine if heat soaked...like up to full operating temp for 30 minutes.
Then, have somebody run the throttle to keep it running, and put the entire can into the throttle body. This will take several minutes. When the can is empty, immediately shut it down and let it cool completely...like for an hour at least.

Remember, it took 20+ years to get that dirty, it will not come out immediately or all at once.
However, if you do as stated above you will have a smoke show like no other, I promise.

I ended up removing the intake and cleaned it manually, then ported it for kicks. Upon removal, I found a lot of carbon on both the intake and exhaust sides of the heads.

Before installing the Mark engine, I pulled the intake and exhaust manifolds and cleaned everything manually. Even that engine, with only 60k miles on it had a lot of carbon in the intake and exhaust portions of the heads. There was not much inside the intake manifold itself, and using Seafoam, I was able to get everything clean like new. The Seafoam really softens the carbon deposits.

I even made a Seafoam drip system to run in the PCV tract to constantly clean the top end if needed. A simple lubricator or Filter, Lubricator for an air compressor tool works pretty well. I used to fill it up and let it drip about every 2 seconds, and it kept my 2v NPI engine really clean, and that one had almost no valve stem seals left and smoked hard.

Good luck
 
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#14 ·
I love Seafoam. I have used it on every used car I have owned.
I have used it in the spray form and the liquid form to clean parts and as an engine treatment. It can be added to the fuel or oil, but I have never put it in the oil.

The key I found after a couple unsatisfactory treatments (little smoke) was heat sinking the intake manifold.
Use it as directed, but make sure the engine if heat soaked...like up to full operating temp for 30 minutes.
Then, have somebody run the throttle to keep it running, and put the entire can into the throttle body. This will take several minutes. When the can is empty, immediately shut it down and let it cool completely...like for an hour at least.

Remember, it took 20+ years to get that dirty, it will not come out immediately or all at once.
However, if you do as stated above you will have a smoke show like no other, I promise.
I did everything except, after application and shutting off, I only let it sit for 10 minutes. Then I drove it again. That was per the instructions on the can.
 
#12 ·
By 20 years old, these cars get heavily gunked up, mostly from the recirculated oil from the pcv valve, and the sludge from the egr. I drive my cars very hard; high rpms just increase the flow from the pcvcircuit, and that doesn't clean anything.
 
#19 ·
Like I said, I use it on all my cars. To answer your question about metal vs plastic intake manifolds...it does not matter because the engine temps remain the same. The plastic obviously has different properties than aluminum but the specific gravity or mass is irrelevant as the temperature envelope is constant.
Get it hot, spray the whole can in there and shut it down for an hour.
Your next start up will be dramatic, I promise you.
My Corolla has a plastic manifold and 275k on it. I did that one in February and got the locals all stirred up with the show.
That thing smoked as much or more and for longer than the 170k NPI 2 valve did. It was spectacular on a crisp -7f NH morning.
 
#16 ·
Prolong the hydrolock for an hour? As that seafoam is sitting for an hour, it is likely leaking past the rings into the oil, so keep that in mind.

Al
 
#17 ·
Seafoam is the commercial equivalent for the old trick of transmission fluid and water, shook up in a coke bottle we used in the 60's.
The water cracks the carbon loose, and the trans fluid dissolves it.
The smoke is equal parts oil fumes and steam.
It basically steam cleans the cylinders.
If you hydrolock it, you're doing it wrong.
 
#18 ·
I don't think you can hydrolock a V8 with a spray can of Seafoam.
The long heat soak has worked for me for many moons, that's why I recommended it. I don't recommend sucking Seafoam in through a vacuum line without a way to meter it.
Good luck!
 
#21 ·
On the subject of Seafoam, I added it to the fuel and I did the intake spray.

The one thing I haven't done is adding it to the oil. My plan was to add some approx. 200 miles before my next oil change.

But looking in through the filler opening, I wonder if there's even a point. It looks pretty clean in there, doesn't it?

 
#24 ·
They all look pretty clean from that view.

I would be very cautious of putting any substance in your oil. Any at all.

The gunk you are after lives in the components downstream of the throttle body, and inside the combustion chamber, intake and exhaust ports of the head. Not internal to the rotating assembly.

If you use Motorcraft synthetic blend oil, you should have no issues of crud building up, it is very good oil.

Frankly, your best bet is to pull the intake and exhaust manifolds after doing the Seafoam routine. The Seafoam will soften the crud nicely.

Then you can pretty much spoon out the bulk crud, and further clean with a brass brush and Seafoam spray until spotless.

My SOHC had about a Dixie cup
of crap in both the exhaust and Intake ports and manifolds. About 12 Dixie cups half full came out
My DOHC had about half as much. Still, it was enough to actually spoon it out.
 
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#27 ·
Anyone who suggests pulling the manifolds after a seafoaming is not someone I'd take advice from, lol.
I usually put a half can in the oil and the rest in the tank, at oil changes.
It will come out black.
Also, adding a few ounces of trans fluid to the oil after a change swells the rubber seals, and helps with the valve stem seals leaking.
To clean the injectors is not easy, and takes some equipment. I'd look for refurbed ones on ebay.
 
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#28 ·
My point was not real clear.
Pulling the manifolds is a job, and best done when upgrading.
I pulled my SOHC intake after looking at it with a scope before and after the Seafoam
I pulled my DOHC manifolds prior to installing the engine.

The Seafoam did not really do much on its own beyond a spectacular smoke show. It did soften the gunk.

Both cases revealed a surprising amount of gunk, and I doubt 1 can of anything would remove it. Maybe if it was repeated many times, it would remove more.

Beyond working well as a parts cleaner, I can't say that it does a lot. I do add it to fuel on occasion and it is my go to upper engine parts cleaner.
Put stuff in your oil at your own peril, I won't condone it.
To truly clean a 20 plus year old intake and or exhaust manifold, there is no substitute for manually cleaning them.
The mechanic in a can BS espoused on here is amateurish at best.
These cars can vote and buy a drink, and there ain't no way a can of stuff will remove 20 years of gunk.
The Seafoam smoke show is cheap entertainment, that's about all.

Good luck!
 
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