i have seen with my own eyes on a jeep 4.0 engine that made a loud tapping/knocking noise that almost sounded like piston slap but was not ...It turned out to be carbon knock (i assume) and the noise almost completely stopped after adding a pint of sea foam..I am going to try that on my northstar which is always making noise and post the results
Sea Foam In The Gas Stopped Knocking In Jeep
- Thread starter crazyoildude
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Never used Seafoam, so I'm curious to know how you intruduced it to the 4.0. Pint to the oil crankcase or fuel? Or did you feed it directly via a vaccum line, like the brake booster?
I just used to run mine up to about 4500rpm on the interstate to blow out the carbon. It would knock like crazy and then I would get a hesitation and poof out the tailpipe and it would be nice and quiet and smooth for another couple weeks. It has over 300k miles, so it built up fairly quickly. Seafoam would have been good after that to clean the residual up.
Originally Posted By: crazyoildude
i have seen with my own eyes on a jeep 4.0 engine that made a loud tapping/knocking noise that almost sounded like piston slap but was not ...It turned out to be carbon knock (i assume) and the noise almost completely stopped after adding a pint of sea foam..I am going to try that on my northstar which is always making noise and post the results
I've had the same experience with my Trailblazer with the 4.2 I6 engine. Mine was also a cold carbon knock and would go away after the engine was warmed up, but when it was cold it would sound like a diesel engine.
I found through trial and error that using Chevron gasoline exclusively seem to keep the problem from coming back. I just poured the Seafoam in the gas tank - didn't feel like smoking up the neighborhood by putting it through the vacuum line.
i have seen with my own eyes on a jeep 4.0 engine that made a loud tapping/knocking noise that almost sounded like piston slap but was not ...It turned out to be carbon knock (i assume) and the noise almost completely stopped after adding a pint of sea foam..I am going to try that on my northstar which is always making noise and post the results
I've had the same experience with my Trailblazer with the 4.2 I6 engine. Mine was also a cold carbon knock and would go away after the engine was warmed up, but when it was cold it would sound like a diesel engine.
I found through trial and error that using Chevron gasoline exclusively seem to keep the problem from coming back. I just poured the Seafoam in the gas tank - didn't feel like smoking up the neighborhood by putting it through the vacuum line.
keep doing it. there's probably a lot in there.
can also "steam" it by spritzing water into the intake while running. it's what we did with our older leaded cars before seafoam.... spritz and rev.... you get steam and [censored] out the exhaust but not all the blue smoke.
can also "steam" it by spritzing water into the intake while running. it's what we did with our older leaded cars before seafoam.... spritz and rev.... you get steam and [censored] out the exhaust but not all the blue smoke.
Originally Posted By: crazyoildude
i have seen with my own eyes on a jeep 4.0 engine that made a loud tapping/knocking noise that almost sounded like piston slap but was not ...It turned out to be carbon knock (i assume) and the noise almost completely stopped after adding a pint of sea foam..I am going to try that on my northstar which is always making noise and post the results
How long did it take to eliminate the knock?
Also, was this idle knock or load knock. Cold engine or warm?
I'm asking because i think I might have one too.
i have seen with my own eyes on a jeep 4.0 engine that made a loud tapping/knocking noise that almost sounded like piston slap but was not ...It turned out to be carbon knock (i assume) and the noise almost completely stopped after adding a pint of sea foam..I am going to try that on my northstar which is always making noise and post the results
How long did it take to eliminate the knock?
Also, was this idle knock or load knock. Cold engine or warm?
I'm asking because i think I might have one too.
Many folks I know with GM v8's in trucks have experienced 'carbon knocking'. They are very sensitive to build up and it is easy to fix.
Option A - "Italian tune up". Fun and easy.
Option B - Kreen, MMO or your favorite additive in the fuel. Works well, just takes a while.
In these engines I have heard it diagnosed as lifter noise, piston slap, etc. It is usually carbon if the miles are high.
Option A - "Italian tune up". Fun and easy.
Option B - Kreen, MMO or your favorite additive in the fuel. Works well, just takes a while.
In these engines I have heard it diagnosed as lifter noise, piston slap, etc. It is usually carbon if the miles are high.
Seafoam is good stuff. Putting it in the gas as opposed to the crankcase or vacuum line (specific way it needs to be done) is ok. The smoke show on most cars after the vacuum line on hot engine and letting it sit for an hour is cool, and the car feels better after.
That, and piston soaks go well with it too.
That, and piston soaks go well with it too.
i put a pint into the gas filled the tank to about 3/4 and then put some slowly into the throttle body while the engine was running then drove it like i stole it on the parkway
the knock stopped pretty fast within 20 miles or so
You didn't allow the engine to stall while pouring into the throttle body, right? ...and only an ounce or two via TB? How many gallons is your gas tank?
Thanks and good job!
Thanks and good job!
I could never get my snow thrower to slow idle. I tried bunch of chemicals. The last one was Seafoam in the tank. When I started it this year and did the first snow storm, I was surprised that the snow thrower now could run at slow idle speed without stalling.
There is a high probability that it was Seafoam which fixed it. Unfortunately, I am worse than Zylander when it comes to fuel additives and add any and all to my OPE and thus I can never pinpoint the succeeding chemical.
- Vikas
There is a high probability that it was Seafoam which fixed it. Unfortunately, I am worse than Zylander when it comes to fuel additives and add any and all to my OPE and thus I can never pinpoint the succeeding chemical.
- Vikas
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Originally Posted By: trooper001
Never used Seafoam, so I'm curious to know how you intruduced it to the 4.0. Pint to the oil crankcase or fuel? Or did you feed it directly via a vaccum line, like the brake booster?
His initial post stated "Sea Foam In the Gas Stopped Knocking In the Jeep" - so my guess, he added it directly to the fuel tank.....
The typical treatment rate is 1 oz. per gallon of fuel....So, in a 16+ gallon tank, you simply add the whole can, preferably to a full tank of fuel.
My 08 Kia had a "tick" at cold start (yea, if you can consider 70 degrees "cold" lol), was using 5W-30 oil....vehicle "specd" 5W-20 but the dealer said their bulk dino Pennzoil 5W-30 would be "OK" well, I added 4 oz. or so to the crankcase one night, the next morning I cranked it up, and the "tick" was gone.
Either it's a coincidence, or the Seafoam actually "thinned out" the 5W-30, allowing it to "flow faster" at cold start....so less metal-to-metal contact at cold start...?
Even after that OCI, the tick never came back....
Never used Seafoam, so I'm curious to know how you intruduced it to the 4.0. Pint to the oil crankcase or fuel? Or did you feed it directly via a vaccum line, like the brake booster?
His initial post stated "Sea Foam In the Gas Stopped Knocking In the Jeep" - so my guess, he added it directly to the fuel tank.....
The typical treatment rate is 1 oz. per gallon of fuel....So, in a 16+ gallon tank, you simply add the whole can, preferably to a full tank of fuel.
My 08 Kia had a "tick" at cold start (yea, if you can consider 70 degrees "cold" lol), was using 5W-30 oil....vehicle "specd" 5W-20 but the dealer said their bulk dino Pennzoil 5W-30 would be "OK" well, I added 4 oz. or so to the crankcase one night, the next morning I cranked it up, and the "tick" was gone.
Either it's a coincidence, or the Seafoam actually "thinned out" the 5W-30, allowing it to "flow faster" at cold start....so less metal-to-metal contact at cold start...?
Even after that OCI, the tick never came back....
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