Is Sea Foam Motor Treatment safe to use through a vacuum line?


Is Sea Foam Motor Treatment safe to use through a vacuum line?

Jim’s answer:

Using Sea Foam Motor Treatment through a vacuum line is easy and safe if you remember one thing: liquids don't compress, and can cause an engine to hydro-lock if too much liquid is applied. Always carefully regulate the rate at which Sea Foam Motor Treatment goes into the engine. Never insert the vacuum line into the bottle of Sea Foam Motor Treatment; always pour Sea Foam Motor Treatment slowly into the vacuum line. With that in mind, you can follow these steps.

To safely use Sea Foam through a vacuum line:

  1. Make sure the engine is at operating temperature (very important).
  2. Find a vacuum line that feeds all cylinders — usually the PCV hose or the vacuum brake booster line is a great candidate. If you are in doubt as to which vacuum line to use, you must check with a certified auto technician. If a technician is not available, or if your engine doesn’t have any vacuum lines, then use the Sea Foam Spray Top Engine Cleaner and Lube method described in another section of this website.
  3. After the correct vacuum line has been located, start the engine and disconnect the vacuum line. With the engine running at idle and at operating temperature, slowly pour Sea Foam Motor Treatment into vacuum line. It is important to control the rate at which Sea Foam Motor Treatment goes into the vacuum line. The engine will labor while you’re applying Sea Foam Motor Treatment. Pour enough Sea Foam Motor Treatment into the vacuum line to make the engine labor at idle, but not enough to stall it.
  4. After 1/3 to ½ can of Sea Foam Motor Treatment has been induced into the engine, shut the engine off and let it sit (hot soak) for 5-10 minutes.
  5. Reconnect the vacuum line. Restart the engine in a well-ventilated area, as the exhaust may be extreme for a short period.
  6. Road test the vehicle immediately after start-up, driving aggressively until the exhaust looks normal. This usually takes up to five miles. It is always better and safer to road test the vehicle like this, to clean the gum, varnish and combustion deposits out of the engine. When you’re done, you will have performed an intense deposit-cleaning procedure on your engine.
  7. Repeat this operation as recommended — once a year or every 15,000 miles.


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