Redline and carbon build-up

[Finklejag]

I been driving around for a month now with Redline 5W-40 in my crankcase on my 2010 GTI Direct Injection 2.0T.

The exhaust tips have black carbon build-up two days after I wash the car. I was hoping the Redline with a Noack of 6 would cut down on the carbon on the tips. It's been about the same as when I was running the FF.

Is it just the nature of the beast with a Direct Injection engine?

 

[hemitom]

Really not a oil problem, i believe its an inheirent problem with D.I engines.

 

[Pablo]

It's the fuel mixture, not the oil.

 

[demarpaint]

Seems like issues associated with the DI engines, and nothing to do with the oil.

 

[simple_gifts]

Surprised no one picked up on the fact that it isn't the oil.

 

[rclint]

It is a issue with fuel mixture, and it could be a startup issue where the fuel mixture is rich, or it could be the running condition.. I would assume you would have a check engine light if anything was wrong with the sensors you could get a check engine light. I also don't have a direct injection gas engine nor have I any experience with them so keep that in mind....

 

[beast3300]

All I cars I have seen so far with DI have this black sooty tail pipe.

 

[HondaMan]

Originally Posted By: Pablo
It's the fuel mixture, not the oil.


+1

 

[gathermewool]

Not just a DI issue. Look closely at the tail pipe of ANY vehicle. The ECU can't keep the mix stoichiometric (14.7 parts air to 1 part fuel) at all times, and actually lowers to a richer mix during open loop operation.

When fuel and air burn, there are different products - gaseous and particulate - that are formed based on temperature. With in a single combustion event there is a flame front with a profile containing different temperature zones. In each of these zones you'll experience. Different combustion by-products, from soot to NOX to CO2 to water. The ECU and emissions control system try to limit the formation of bad gases (like NOX) with proper engine management, using the CATS to catalyze the byproducts formed during transients (which is always in a car)

 

[Finklejag]

Okay, thanks guys.

 

[Rican]

you are definitely running rich. Do you have an AFR gauge? I don't know exacly how your car is tuned from factory, but when I was running high 10's at wot the bumper would get black build up a lot quicker. Also if ur running under 14.5afr's while cruising it might get dirtier as well. A slight leaner tune should take care of it.

Once I made the switch to e85, the carbon build up stopped. I can go 1 1/2 months (one week on gas) without washing the car and it still looks good.

You should try e85 if available and you tune ur own car, or if you have a tuner around that could take care of it. Mine drives a heck of a lot better after I did the change and it spools much sooner all through out the band. Also the extra whp is nice too.

 

[Nederlander75]

Since started experimenting with E85 mixes (summer of 07) I have noticed less carbon on the exhaust tips as well. The heavy carbon comes back without fail on just pump premium regardless of what car it is, my DI or my PI engines. Its certainly not oil related unless you see yourself going through large amounts of make up oil.

 

[shpankey]

I have an 09 Mazdaspeed 3 Direct Injected Turbo and all of ours run pig rich. They are actually tuned this way from the factory on purpose as "rich is safe". Running lean can = boom.

It can be tuned out if you go aftermarket ECU kit. Like something from COBB, CP-e, Hypertech, etc etc and then have a tuner custom tune your car. Even then, you should stay a bit on the rich side of things for safety.

 

[ItsuMitsubishi]

Yes, manufacturers shipping DI engines here give us very rich ECU programs. It's been said to stave off NOx for EPA compliance. 10-11 AFRs in boost are outrageous. Y'think that has something to do with washing out the cylinder walls and diluting oil? Sheesh

 

[ItsuMitsubishi]

Originally Posted By: Rican

Once I made the switch to e85, the carbon build up stopped. I can go 1 1/2 months (one week on gas) without washing the car and it still looks good.


Running high Ethanol fuel blends actually seems like a great idea for DI engines.

 

[saaber1]

100% normal for these cars. Lots of people fuss about it and some try to clean their tailpipes all the time but for me I just live with it. My boxster S had the same issue and was dirty again after about 1-2 weeks after a thorough cleaning. Wasn't worth the trouble to clean for me. I think the tailpipes should have come out in a black finish instead of chrome.

 

[ARB1977]

DI engines have the concept of diesel engines. Any diesel engine will have black build up on the tail pipes....so will DI engines.

 

[Rican]

me, I don't use the e85 to keep the bumper clean

I use it to be able to run more aggressive timing, I still try to keep it a bit richer than gas, cuz e85 seems to give u more power this way. I start in the low 12's at low rpms and tapper down to 11.5afr at higher rpms. It pulls like a beast.

I guess it all depends on ur setup, I'm running a Garrett T3/T04E 57trim, 63ar hot side and 60ar cold at 8.5 psi. Currently putting down 270whp, which isn't bad considering that this car puts down around 140whp stock. I have run as lean as 12.5 without detonation and pulling about 3.5 degrees by 9psi, just to show the great potential e85 has for turbo'ed cars.
BTW, I don't own an MS3, but it still a turbo'ed car. (Scion tC ;-))

You could do like the other posters said and start up by blending. Having a obdII like a scangaugeII will help you keep an eye on your fuel trims to make sure ur ECU is keeping up with the blend. I started with 25% e85 and kept adding more, until I got it down. Try it, you'll love it.

 

[Steve S]

Originally Posted By: simple_gifts
Surprised no one picked up on the fact that it isn't the oil.
On Bob is the Oil Guy it has to be the oil.

 

[OVERKILL]

Originally Posted By: gathermewool
Not just a DI issue. Look closely at the tail pipe of ANY vehicle. The ECU can't keep the mix stoichiometric (14.7 parts air to 1 part fuel) at all times, and actually lowers to a richer mix during open loop operation.

When fuel and air burn, there are different products - gaseous and particulate - that are formed based on temperature. With in a single combustion event there is a flame front with a profile containing different temperature zones. In each of these zones you'll experience. Different combustion by-products, from soot to NOX to CO2 to water. The ECU and emissions control system try to limit the formation of bad gases (like NOX) with proper engine management, using the CATS to catalyze the byproducts formed during transients (which is always in a car)


Mine are clean.......... The only one that got carbon was the Mustang, and it had no cats and wasn't stock so...

I believe the issue the OP is experiencing is due to (as many have already stated) the way the DI engines operate.