What additive helps get rid of carbon

[crazyoildude]

OK so car in question is a 95 Cadillac and it has the northstar v8
Car has 44000 original miles (old lady miles) really! engine has a knocking sound but im pretty sure it is carbon buildup, what additive can i put into the gas tank to get rid of the carbon it belongs to a neighbor and i want to try and fix this without taking the motor out.
I believe the problem is carbon because the knock is not always there and sounds like a bad belt tensioner sometimes (its not) and you can hear it cold more than hot.. Car has never seen over 60 mph...those northstars love to open up..
What about sea foam??

 

[mechanicx]

For the gas I would use a big bottle (treats 20 gals) of Techron fuel system cleaner. For the oil I think I'd add up to a 1 qt bottle of Marvel Mystery oil. Run it for up to 3k miles and see how it does.

 

[Steve S]

Try an Italian tuneup.

 

[Paul2007]

I vote for either Seafoam or B-12. For the oil, plan on a change right away. This is the one time I will say to put ATF, MMO, or kerosene into the oil, as a flush/cleaner. Run it for 5 minutes and drain it. Replace with appropriate oil and a new filter. DO NOT RUN THE ENGINE MORE THAN 5 MINUTES WITH ANY OF THIS STUFF IN THE OIL!!!!!

 

[hate2work]

Amsoil Power Foam, use as directed, but let it sit longer. I use this stuff on 2-cycles daily, I've never seen a product remove carbon/calcium deposits better or faster.

 

[crazyoildude]

Im leaning towards putting something into the gas because the carbon is inside the combustion chamber on the pistons and head,,, Etc..
I believe its carbon at least ..

 

[demarpaint]

Red Line FI cleaner, run a few tanks with it added, and get on the car. Run it hard!

 

[crazyoildude]

Hi Steve tried that stomped on it maybe 10 times one time bringing it up to over 100mph but still im pretty sure its a carbon buildup.
The engine looks like it was never used looking through the oil fill hole engine is clean!

 

[demarpaint]

You can also try water through a vacuum line. It's been discussed here, just make sure you use very hot water, and don't lock up the engine. Water can't be compressed, but it does a nice job at cleaning up carbon in the combustion chamber.

 

[mechanicx]

Well I'm standing by my recommendation to not put anything in the gas other than Techron. Also with MMO that isn't so harsh on the oil and has a good reputation as an effective, safe and inexpensive engine cleaner

.

 

[mechanicx]

Originally Posted By: crazyoildude
Hi Steve tried that stomped on it maybe 10 times one time bringing it up to over 100mph but still im pretty sure its a carbon buildup.
The engine looks like it was never used looking through the oil fill hole engine is clean!


Wait if the engine looks clean. Maybe skip the cleaner in the oil for now unless it's MMO, and use the fuel cleaner. This engine might have piston slap and no additive is going to fix it.

 

[VK56VD]

Put in a quality Fuel Injector Cleaner such as Redline, added to a full tank of 93 Octane.

You can Auto-RX the engine.

 

[crazyoildude]

Im have used mmo for over 25years great stuff problem is these northstar engines leak oil and that would increase the leak and besides what will that do for carbon in the combustion chamber?

 

[dickwells]

Put water into a northstar and someone will be buying a new engine.

 

[crazyoildude]

it could have piston slap but i don't think so sounds like a bad belt tensioner but it is not

 

[DieselTech]

BG44K or Redline sl-1

 

[JSRT4]

Redline fuel system cleaner, with Lucas Upper Cylinder lube in the gas tank for the chambers and injectors. I'd run a bottle of Riselone in the oil crankcase, I like it as it is gentle enough and comes with a carrier oil that isn't overly thin. I got some decent carbon out of my engine with this combo. I also ran some High mileage oil with this combo. Worked well for me.

 

[hate2work]

Back in the day the only way I could get the carbon off the top of a piston was to remove the cylinder and scrape off the top of the piston with a knife or buff it with a wire wheel on a bench grinder. These days all I do is spray Power Foam liberally on the piston, walk away for an hour, come back and rinse it with gas....and it literally melts off.

I'm not sure how you would get this stuff into your combustion chamber...maybe a vacuum line? But if you can get it in there, it will work.

 

[ADFD1]

Originally Posted By: dickwells
Put water into a northstar and someone will be buying a new engine.


Have you done it in a Northstar engine, and ruined one? I've done it a few times in different used cars I bought and it worked out well. But I was supervised by my uncle and he showed me how to do it.

 

[The Critic]

Use an induction system cleaner such as GM TEC, BG ISC or Amsoil PowerFoam.

Then, add Amsoil PI to the fuel tank to complete the clean-up.