Carbon Buildup with DI Engine

muhsfink07 · June 28, 2017

Hey Guys,

Has anyone had to clean their intake runners yet? I know that with the DI injectors there can be an issue with carbon fouling as the miles rack up. Has anyone had a problem with this and had to have it cleaned yet?

Ive got about 35K on my truck right now.

Thanks!

jono20 · June 28, 2017

I've been doing a lot of reading about this lately too, it's an interesting problem. I appreciate what Toyota has done with the new 3.5L V6 in the Tacomas, they have both port and direct injection. Port injectors operate under low load conditions and should eliminate the carbon buildup issues on the valves. Wonder what GM's long term fix is going to be...

inb4 catch can recommendations...

Silverado Steve · June 28, 2017

Go to you local auto parts store or Wally World and buy a can of GDI Intake Valve cleaner and perform every oil change. Costs $9-$12.

Edited June 28, 2017 by Silverado Steve

truckguy82 · June 28, 2017

Hey Guys,

Has anyone had to clean their intake runners yet? I know that with the DI injectors there can be an issue with carbon fouling as the miles rack up. Has anyone had a problem with this and had to have it cleaned yet?

Ive got about 35K on my truck right now.

Thanks!

Gm did a pretty good job with the motor design compared to a few other manufacturers, especially some of the earlier german DI motors. Regardless, I plan to do mine around around 60-75k miles. I'm at 37k now and I don't have any of the symptoms. I'm sure if I took the intake off I'd see carbon buildup though.

Too much work to do it frequently. The only real way to do it is to take the intake off and manually clean the intake ports and valves with a wire wheel or media blast.

I don't have a catch can though. I do spray sea foam in through the throttle body right before oil changes, doubt that does much though.

muhsfink07 · June 28, 2017

anybody know how much a cleaning would cost?

truckguy82 · June 28, 2017

anybody know how much a cleaning would cost?

DIY

Will be difficult to find someone with enough integrity to do it properly and not drop carbon deposits into the cylinders. It's way easier and faster to do the job and not to care and it's easy to hide.

Edited June 28, 2017 by truckguy82

15 Z71 · June 28, 2017

My friends 14 has 70,000 on it now. Motor has never had anything but oil changes and it run perfectly fine. I would not be to worried about it at such low miles.

truckguy82 · June 28, 2017

My friends 14 has 70,000 on it now. Motor has never had anything but oil changes and it run perfectly fine. I would not be to worried about it at such low miles.

Yeah, its not "needed" I'll just be doing it for hp and fuel economy, probably worth about 10-15hp @ 70k

On corvette forums a shop did it at like 20k miles ad they claimed it made like 20 more hp. I don't buy that, but I'm sure it has some effect on hp after awhile.

truckguy82 · June 28, 2017

There's guys on audi forums that did before and after dyno's after like 70k miles, one guy with an rs6 made 100whp after cleaning lol. I believe it too, 2000's audi/vw DI had horrible carbon buildup.

Sierra706 · June 28, 2017

My 2006 Passat desperately needed one at 100k. My mechanic used walnut shells

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Z45 · June 28, 2017

Using solvent based upper induction cleaning on GDI engines that is used while the engine is running will and oes cause scouring/scratches on the pistons and cylinder walls as the hard deposits break loose.

amxguy1970 · June 28, 2017

Yeah, its not "needed" I'll just be doing it for hp and fuel economy, probably worth about 10-15hp @ 70k

On corvette forums a shop did it at like 20k miles ad they claimed it made like 20 more hp. I don't buy that, but I'm sure it has some effect on hp after awhile.

That is quite the assumption there...

There's guys on audi forums that did before and after dyno's after like 70k miles, one guy with an rs6 made 100whp after cleaning lol. I believe it too, 2000's audi/vw DI had horrible carbon buildup.

Those engines were notorious for it as they were not designed as DI engines from the get go. This engine (and many later completely new engines) that are designed for it show minimal wear over the long run in most cases. Being in DFW I have had my truck to a few of the largest dealers in the country and asked a couple of techs about it, said they have had many trucks in with well over 100k on them and no issues, some minor build up but nothing that causes problems or effects performance.

Using solvent based upper induction cleaning on GDI engines that is used while the engine is running will and oes cause scouring/scratches on the pistons and cylinder walls as the hard deposits break loose.

Not if you do it early and often. If you wait for 100k+ yeah I can see that in some extreme cases but it certainly isn't guaranteed.

Point is OP I wouldn't worry about it, the millions of hours spent going over the timing and design of these motors took care of most the issues. Run some cleaner through there once or twice a year and you will be fine, some other area will have a problem before buildup is causing any issues.

Tyler

truckguy82 · June 28, 2017

That is quite the assumption there...

Those engines were notorious for it as they were not designed as DI engines from the get go. This engine (and many later completely new engines) that are designed for it show minimal wear over the long run in most cases. Being in DFW I have had my truck to a few of the largest dealers in the country and asked a couple of techs about it, said they have had many trucks in with well over 100k on them and no issues, some minor build up but nothing that causes problems or effects performance.

Not if you do it early and often. If you wait for 100k+ yeah I can see that in some extreme cases but it certainly isn't guaranteed.

Point is OP I wouldn't worry about it, the millions of hours spent going over the timing and design of these motors took care of most the issues. Run some cleaner through there once or twice a year and you will be fine, some other area will have a problem before buildup is causing any issues.

Tyler

Yes it is the assumption

Your assumption is that is does nothing because a few techs looked at it and hooked up a scan tool and didn't notice anything? Do they have a magic dyno at the dealer to tell them there is no horsepower lost?

My assumption is 10-15 hp, and I can show you an actual before and after dyno that says it's more than that with a lot less miles.

jono20 · June 28, 2017

Just learned that the 2017 F-150 has a new 3.5L Ecoboost that's also added port injection on top of the direct injection. Time to place bets on how long it's going to take GM to make the same change...

Silverado Steve · June 28, 2017

That's assuming you have large amounts of carbon deposits. As others have mentioned top end induced cleaner won't cure 100K+ of neglect and carbon buildup. If people are worried about valve coking and are proactive about it early in their engines life, that will be more successful than worrying about it later in the engines life. With that all being said, i have complete faith that if you use a quality oil and change the oil based on OEM recommendations many if most owners wont fall victim to crippling carbon build up in their engines.

Using solvent based upper induction cleaning on GDI engines that is used while the engine is running will and oes cause scouring/scratches on the pistons and cylinder walls as the hard deposits break loose.

Edited June 28, 2017 by Silverado Steve