heres a write up for anyone that wants to use it; got it from a guy off that other site
How to Seafoam your 1997-2003 Pontiac Grand Prix
By Rob (caruch6392)
Things you need to Seafoam your engine: To get the full benefit of a complete treatment you will need to following items:
• 2 cans of Seafoam
• Medium sized flat head screwdriver
• Pliers
• 1 long, skinny funnel
• Measuring cup with oz. labels
• Paper or regular cup
• Sharpie, or black marker
• Extra person to help with phase 3
Things you may consider changing after a Seafoam treatment:
• Spark Plugs
• Fuel Filter (AC Delco brand is recommend as it is the OEM brand)
Note: The ACDelco fuel filter can be found at Advance Auto Parts. Part No. GF578.
Time Frame:
The time frame to complete a 3 phase Seafoam treatment is around 30-45 minutes. This includes the 20 minutes of having your car sit to let the Seafoam soak inside your engine.
What is Seafoam?
Seafoam is 100% petroleum and is not harmful to your engine with proper use. The purpose of Seafoam is to remove the carbon build up inside your engine, intake manifold and fuel injectors due to regular driving. If you are suffering from poor mileage, sluggishness or the RPM’s surging, then these instructions may help you with these problems.
Note: Seafoam can be found at any Advanced Auto Parts store for around five dollars a can. Part No. SF16
How to Seafoam your car:
Phase 1 of 3: Fuel Injector Cleaning
Note: During phase one, when pouring the Seafoam into the gas tank, your car should be turned off.
1. To start off, make sure you have a full, but not overfilled gas tank, as you will be pouring your first can of Seafoam into your gas and you do not want the concentration to be too powerful or too weak.
2. After filling up your gas tank use the long, skinny funnel and insert it into the gas tank.
Figure 1-1
3. Shake the first can of Seafoam briefly and gently, then, using the funnel, pour the entire contents of the can directly into the gas tank. (See figure 1-1)
4. After the can is empty, remove the funnel and clean up any extra drips that may have gotten on your car’s paint.
5. Now, put your gas cap back on and go for a short drive. This will let the Seafoam mix in your gas tank and slowly clean out your injectors.
Note: Because we do not want to dilute the Seafoam mixture any more, make sure you drive with this tank of gas until it gets to a pretty low level before filing up again.
Phase 2 of 3: Oil and Crankcase Cleaning
Note: During phase two, when pouring Seafoam into your crankcase, you car should be turned off and the car should be cold. We do NOT want a room temperature liquid being poured into a 200+ degree engine. This may cause some shock to valvetrain parts.
1. After your car is completely cooled off we are now ready to begin pouring a measured amount of Seafoam into your oil.
2. The measurement for the amount of Seafoam per quart of oil is 1.5 ounces per quart. Since Grand Prix’s take 4.5 quarts, we do some math and do (1.5) x (4.5) = 6.75 ounces of Seafoam that you will be pouring into the oil.
3. A can of Seafoam is 16 ounces so we will pour a little less than half of your second can of Seafoam into the oil.
4. To get the correct amount, take your measuring cup and fill it with regular water up to the line of approximately 6.75 to 7 ounces. You don’t have to be perfect but try and get it around 7.
5. Then transfer this water from the measuring cup into your paper or regular cup.
Figure 1-2
6. Using your black marker, make a line on the outside of the cup where the water line is currently at. This marks exactly how much Seafoam you will pour into this cup in the next few steps. (See figure 1-2)
7. Now that you have the measured amount marked off, empty the cup of water and make sure the cup is dry.
8. Using your second can of Seafoam pour it into the cup up to the marked line.
Figure 1-3
9. Once that is done, open up the oil filler cap and slowly pour all the measured Seafoam into the crankcase. You can use the funnel if necessary. (See figure 1-3)
10. Put the oil filler cap back on.
11. Do not drive your car for more than 250 miles with this Seafoam solution now in your crankcase. It is safe but very aggressive. It is recommended that you change your oil and oil filter after 100 miles.
Note: Do not drive your car for more than 250 miles with the Seafoam in your crankcase. The solution is safe but very aggressive. It is recommended that you change your oil and oil filter after 100 miles.
Phase 3 of 3: Top End Clean
Note: During this phase your car needs to be running long enough to enter a closed loop. Go for a short ride so that you car warms up to normal operating temperature which is around 180 or so degrees.
Note: During this phase there may be heavy white smoke that will come out of the exhaust. Be sure you are in a WELL VENTILATED area
1. By now there will be approximately half a can of Seafoam left. This will be used for phase three.
2. For people with the L67 engine you will use the connection in figure 1-4. It is a different vacuum line to suck the Seafoam in, so you don’t strip your supercharger rotors. (Thanks to Jason who supplied the supercharger picture)
Figure 1-4
Note: For people with the L36 or naturally aspirated engine, ignore step 2 and continue on to step 3.
3. In order to get the Seafoam to interact with all the cylinders we need a vacuum line that goes to all cylinders. This is the brake booster line. It is the hose attached to the yellow “cap” looking piece.
Figure 1-5
4. The brake booster line is highlighted by the green arrow and needs to be pulled off. (See Figure 1-5)
Note: The brake booster line may be difficult to pull off. You may use some force to pull it off. If this fails then use a flat head screwdriver or pliers and pry the line off of the connection.
5. After the brake booster line is off, insert the long, skinny funnel into the brake booster line. Making sure it snugly fits inside the booster line.
Note: During the next step it will be hard to start the car. Keep the ignition cranking until the car starts. When it does start it may stall as we now have an enormous vacuum leak and the engine cannot stabilize itself. If it does stall, start it up again and keep it alive by holding the engine at around 2000rpm – 2300rpm. If it does not stall then simply keep the engine at a steady 2000rpm -2300 rpm.
Note: This next step is where thick, white smoke may occur.
6. Have your extra person or friend get in the car and start the car.
7. Slowly pour in most of the remaining Seafoam down the funnel.
Note: This will make the engine unstable again, and it may begin to sputter. Be sure to keep the engine at 2000-2300rpm’s.
Note: The next step we are attempting to stall the engine by flooding it with Seafoam. This will leave the Seafoam to sit in the cylinder banks and eat away at the carbon If it does not stall right away after dumping the rest of the contents of Seafoam immediately turn off the car and finish pouring the Seafoam until it’s finished..
8. When you have an ounce or two of Seafoam left, quickly dump the entire contents of the can down the funnel and have your friend take their foot off of the throttle and quickly turn off the car.
9. Remove the funnel from the brake booster line
10. Re-connect the brake booster line by pushing it back onto the connection from which you pulled it off.
11. Let the car sit for a minimum of 10 minutes. It is recommended to let the car sit for 20 minutes.
Note: For the next step it will be difficult to start the car. The engine is currently soaked with Seafoam and may take a bit of cranking to finally have the engine turn over. If you have trouble when starting the car, give the car a little extra fuel by pushing the throttle a few times.
12. After the car has been sitting, attempt to start up the car.
13. Once the car turns over, it may want to stall again. Let the car struggle but keep it alive when necessary.
14. Let the car idle for about 10-15 seconds.
Note: This next step is where thick, white smoke may occur. Be sure to be in a well ventilated area. If there is no smoke while you are driving, continue to drive aggressively to still flush out the Seafoam.
15. Take the car out for a spirited drive. Be sure to reach all areas of the rpm range. Make sure to go 100% throttle a few times to flush Seafoam out of the engine. Continue to drive aggressively until the smoke (if any) decreases dramatically.
16. Congratulations! Your car is now mostly carbon free. You should notice a smoother idle and less surging and better overall responsiveness.
17. Do not forget to change the oil and oil filter after 100 miles.
