EngineeringGeek
Thread starter
Originally Posted by Bullwinkle007
One way to clean the backside of the intake valves is to use carb and intake cleaner and spray it down into the intake while someone holds the throttle at 4k RPM, and spray the entire can. Then change the engine oil. That will also clean the intake manifold. I also clean the MAF sensor every oil change with MAF sensor cleaner
I've seen zero independent proof any spray works. If you've ever seen and felt carbon build up on a D.I. intake valve it might as well be black concrete. So, no surprise, sprays, Seafoam, etc. don't seem to do much to magically soften and dissolve rock hard baked on carbon build up. There's a reason manufactures usually only recommend mechanical cleaning methods such as walnut shell blasting. Sprays don't work and there are plenty of independent tests that show they don't work.
@KevinP there is no "fuel wash" of the back side of the intake valves in a D.I. engine from all the research I've done. When the intake valve is open you have nothing but air and PVC vapors flowing IN to the cylinder and ideally nothing flowing the other way. The last thing you want for fuel efficiency is having raw direct injected fuel going back into the intake manifold where it would be wasted and that would also require some sort of reverse flow which would be hard to induce. Everything about efficient combustion for maximum fuel economy, lowest emissions, and greatest power, opposes dumping raw fuel mixture back into the intake manifold. i think it's a myth. If someone has factual evidence to the contrary I'd love to see it?
One way to clean the backside of the intake valves is to use carb and intake cleaner and spray it down into the intake while someone holds the throttle at 4k RPM, and spray the entire can. Then change the engine oil. That will also clean the intake manifold. I also clean the MAF sensor every oil change with MAF sensor cleaner
I've seen zero independent proof any spray works. If you've ever seen and felt carbon build up on a D.I. intake valve it might as well be black concrete. So, no surprise, sprays, Seafoam, etc. don't seem to do much to magically soften and dissolve rock hard baked on carbon build up. There's a reason manufactures usually only recommend mechanical cleaning methods such as walnut shell blasting. Sprays don't work and there are plenty of independent tests that show they don't work.
@KevinP there is no "fuel wash" of the back side of the intake valves in a D.I. engine from all the research I've done. When the intake valve is open you have nothing but air and PVC vapors flowing IN to the cylinder and ideally nothing flowing the other way. The last thing you want for fuel efficiency is having raw direct injected fuel going back into the intake manifold where it would be wasted and that would also require some sort of reverse flow which would be hard to induce. Everything about efficient combustion for maximum fuel economy, lowest emissions, and greatest power, opposes dumping raw fuel mixture back into the intake manifold. i think it's a myth. If someone has factual evidence to the contrary I'd love to see it?