Any suggestions on direct injection cleaners? Some are part of a induction system that force the solution into the intake and some you just pour in the fuel tank. Any success stories? Fails?
Direct Inject Cleaning solutions
Collapse
X
-
Just throwing this out there,
The inherent problem with DI is the fact that the fuel isn't injected onto the back of the valves causing the carbon build up.
So if you think about it, nothing you'd pour in the tank could possibly work. -
And I'll answer it.With todays camshaft designs there is a lot of overlap which causes reversion into the intake manifold (sometimes now called a "surge tank").The carbon is a product of the combustion gases that revert into the intake.
General Motors,Hyundai,Kia and some others recommend as maintenance adding a bottle of their branded fuel system or fuel injector cleaner at each oil change.Following this will prevent carbon buildup on intake valves as the cleaner is carried to the intake valves with the combustion gases.It does work.
BMW recommends walnut shell blasting of the intake valves as maintenance .Comment
-
But do you think that tiny amount of reversion from cam overlap has more to do with deposits than the PCV system?
Generally speaking most OEM cam designs have little if no overlap and with VVT I would suspect even less overlap, even with more aggressive lobe design.
Maybe I used "carbon deposits" looselyComment
-
Valve guides.
They all have some lubrication (they CAN'T run DRY) and over time it builds up.
It used to be cleaned using better grades of fuel with TBI and PORT injection systems but the GDI doesn't allow cleaners in fuels to get to the intake valves where the vacuum (low pressure) tends to pull what lubrication is there down the guides.Comment
-
Could very well be.There is also a calibration update for P0300,at least on Acadia.Just did one after cleaning carbon deposits with GM upper cylinder cleaner and replacing spark plugs(which were badly carboned).Comment
-
That's interesting. Sure doesnt make sense to me when you compare 150k mile engines direct vs conventional.
Read somewhere the other day one of the OEMs is adding port injection to a direct injected engine to help keep the valves clean. I'll try to find that article.Comment
-
The OEMs will have to do something to correct this issue with direct injection.As we all know,expecting customers to follow their maintenance Schedule is wishful thinking.Comment
-
If you're looking for opinions, I've got one. I've never seen any type of Foo Foo Juice work to clean valves on a DI car. I've seen lots of claims, but if you take a before/after shot with a bore scope I've found little-no difference.
The only thing I've seen work perfectly so far is walnut shell blasting. It's a lot more work than running a cleaner through the engine, but at least you'll have something to show for your efforts.
Joe"You don't build a reputation on what you're going to do"
Henry FordComment
-
If you're looking for opinions, I've got one. I've never seen any type of Foo Foo Juice work to clean valves on a DI car. I've seen lots of claims, but if you take a before/after shot with a bore scope I've found little-no difference.
The only thing I've seen work perfectly so far is walnut shell blasting. It's a lot more work than running a cleaner through the engine, but at least you'll have something to show for your efforts.
Joe
WIN WINComment
-
Comment
-
If you're looking for opinions, I've got one. I've never seen any type of Foo Foo Juice work to clean valves on a DI car. I've seen lots of claims, but if you take a before/after shot with a bore scope I've found little-no difference.
The only thing I've seen work perfectly so far is walnut shell blasting. It's a lot more work than running a cleaner through the engine, but at least you'll have something to show for your efforts.
Joe
on the valves and let sit will soften the carbon so it can be wiped off.
One Hytac operator suggested that I use oven cleaner,it didn't work as well as the GM stuff.Comment
-
I think most that carbon build up comes from blow by and the oil vapor pulled through the crankcase ventilation system , especially with turbo charging where the amount of oil misting that cokes on the back of hot valves can be reduced with a catch can system if drained regularlyComment
Comment