Write-Up: Seafoam to restore lost horsepower

I just bought seafoam last night and put it in my gas...then I took it out on the parkway and flogged it a bit. A couple WOT spurts to around 95, 95 MPH... the car had some better pick up and go, however I still need to put Seafoam into my crankcase and through do my top half. I'm waiting though because after reading I shouldnt leave it in the crankcase for more than 250 miles, well I just had an oil change this passed week. So i'll wait until its due again. But I may try some more in my gas sometime within the next couple tanks or so.

im scared to try this in my car i have 3 cans of it im afraid that if i try it then riv wont want to start up any more

It's fine Corey, just follow the directions in the write up. It made a BIG difference in my car.

Corey..it's cool, you might need to give the car a little throttle to start it...but that's it.

I've done this a 4-5 cars and it is safe. Follow the directions and all will be well.

The only thing I would change on the writeup would be the brake booster as the vacuum line being used. That is a huge vacuum leak. I prefer getting a length of vac hose for the fitting on top of the SC in both S1 and S2's or going off one to the TB on the NA motors.

I'd have to agree with Bill on not using the brake booster hose. I did the first time I Seafoam'd the Riv this summer, won't do that again. Use a smaller diameter hose on the capped vac fitting on top of the SC.

1998 Riv wrote:

I'd have to agree with Bill on not using the brake booster hose. I did the first time I Seafoam'd the Riv this summer, won't do that again. Use a smaller diameter hose on the capped vac fitting on top of the SC.

I have done the seafoam in the fuel but might have to do it again, I didn’t read the suggested applications and added it to a full tank of gas, will have to wait and see if it helps?
I did the top end cleaning, I used a smaller hose stuck into the brake booster hose and used hose clamp pliers to regulate how much seafoam it sucked in, it smokes and runs just like when I used to pour trani fluid into carbureted engines. The seafoam I’m sure helped but with the maintenance that had been done on this Riv in the past I am going to have to do more. I’ve had to clean around the butterfly on my truck, removing the air intake and spray injector cleaner right onto the butterfly. I get a sticking accelerator pedal and I’m sure that is the problem.
I’m waiting on the oil until I know I’ll have time to change it because I’m sure with the way this car has been maintained the filter will clog almost immediately! So I’ll seafoam that when I’m sure I can change it right away.

got a couple cans of seafoam,1 for the fuel 1/2 for the crank case 1/2 for the upper intake....all worked according to plan.i performed this sequence of engine cleaning in a church parking lot at 1:am in the morning! after doing the fuel then the lower crank case,i then siphoned the remaining seafoam into the vacum line,little by little,then put the remaining S.F into the vac tube,stalled the rivi,waited 10 or so minutes then started her up.. boy! the plume of smoke that came out of the engine bay must have woke up all the saints!! it lingered and wafted in the air like a ghost for what seemed like a long time....even the sleeping neighborhood dogs noticing something out of the ordinary was up started to bark like gangbusters.....!!! all the animals started howling! st.francis of asisis,couldent calm em down!....waited a few min more took of for a spirited drive...things are working better i think...just a little problem,the engine ran a little rough the next day.the revs dropping a little below 1000 rpm,s.....i think the S.F just needs to work its way through the fuel system...or i have a clogged cat exaserbated by the cleaning...or both...is this normal?...guess i have to wait until the next fill up and see if it goes away.........

You need to change the oil ASAP.... all the carbon deposits you cleand off the valves an pistons..dirtys your oil..an clogs your filter....

and your car should be idling below 1000..

Yeah, and if you dumped it in the crankcase, you need to change oil at no more than 100 miles anyway. RPM's should not be over 750-ish if you are running a stock cam still, fully warmed up.

as said before, change the oil.
the SF in the gas should act like octane booster and make it run better, not worse. i wouldnt put new gas in untill you have run the seafoam out.
also check your plugs, if you had a lot of carbon build up it can foul plugs. a few WOT runs may clean them off, but if i were you i would pick up a set of AL 605's or 104's if your modded. they are inexpensive and work great in s/c cars.
lastly, if the fuel filter is old, then you may want to get a new one. the SF probably knocked up some dirt and rust at the bottom of the tank and it could clog an old filter.

btw, was the smoke white or grey?

for sure,the revs are now spiking up and down insted of staying steady, the car seems to want to chug it self off. otherwise the treatment seems to be working fine. the smoke coming off the engine was white. but i got nothing out the tail pipe. thats why i suspect a clogged cat. but i might be wrong,either way the cat is coming off real soon. my fuel filter was changed in august of 07, so its still good. but im going to change it along with the oil at 100 miles plus the plugs. btw, what oil filter do you guys recomend for the rivi? the fram filter seems more suited to a 4 banger in size than a 6 cyl! also went and changed out the front sway bar bushings along with the end links all the way around,found the perfect fitting poly bushings at a.z they were just out of stock for the sway bar bushing for the back.. thanks again people!

WOW when i seafoamed my ride..... it came out the tail "pipe's" im taking a video of it later this summer when i do my car again...... WOW that was fun times

acdelco pf52 filter (larger sized than stock)
FRAM is the worst filter ever made, if you dont believe me, cut one open.
all of the smoke should have been from the exhaust. which line did you put the SF in?

the PF52 is the way to go. If you look it up in a book it's for a late-90s chevy 4.3 S-10 or GMC Jimmy. Get the AC or better filter.

Mr.Riviera wrote:

FRAM is the worst filter ever made, if you dont believe me, cut one open.

I use the delcos,or mobile 1 filters....

i put the s.f into the brake boost vac line with no problem mr.riv. not a bit came out. im sure i will see better results when i yank the cat though.......i dont know...just a feeling. i ran a whole year with my old cars cat really clogged up..cant imagine how she ran,but she did.

after seafoaming the riv, i do feel a difference in performance. only prob is, when i did it i had no idea that the cat was mostly clogged... no harm done though. changed the oil and it was real black. so i know it did its job.

i redid the upper intake seafoaming, and this time it came out the exhaust. but not alot of smoke,just a small amount. that tells me my cat, when i s/fd for the first time ,was tottally clogged! even though i could see a little light through the cat. after installing a straight piece of tubing,my mpgs have gone up quite a lot. at least 5-6 miles over normal. thats good for me!

Afraid your going to miss the Olympics?

Well fret no longer!

Seafoam your car!


I just did and my neighbors love me! I could tell by the way they were waving their pitchforks and torches!

On the Seafoam site, it all suggests that you have a technician perform the cleaning. What products do you use, and how do you use them? You all seem to love this stuff and I'd like to test it out on both my cars.

captshiner wrote:

On the Seafoam site, it all suggests that you have a technician perform the cleaning. What products do you use, and how do you use them? You all seem to love this stuff and I'd like to test it out on both my cars.

Works great in your gas.

Works great in your oil. Do some research on that first.

Works great going through the Intake system. Once again, research.

pour 1 pint into the gas tank with at least 8 gallons of gas

pour 1/2 pint into the oil (crankcase) make sure you change your oil and filter before 500 miles after adding...

add 1/2 pint to you induction system by direct vaccum line like from the brake booster...

...you'll need a special licence from the city if your in city limits
....a hazmat suit
....an incredible lung capacity to hold your breath for 10 minutes
....the audacity to try this in daylight
....6 years of college


...I think thats it.

"...you'll need a special licence from the city if your in city limits
....a hazmat suit
....an incredible lung capacity to hold your breath for 10 minutes
....the audacity to try this in daylight
....6 years of college"

Hope that's sarcasm, Chicken.

it is!

Thought so. I wish one of you guys lived near me, I'm new to this whole 'amateur mechanic' thing and trying new things makes me nervous. I need someone to watch over me.