Direct Injection and Carbon Buildup

[lildisco]

how's that possible when no fuel/cleaning additives hit the back of the intake valves?  Having a Catch Can would prevent most of the deposits from forming on the intake valves in the 1st place.  

Edited June 17, 2020 by lildisco

[1004ron]

3 hours ago, IcyFridge said:

With direct injection, hitting boost will clean those deposits out. Focus ST guys goose it every now and then to cook off the deposits. Driving like a granny all the time builds the deposits more. 

 

24 minutes ago, lildisco said:

how's that possible when no fuel/cleaning additives hit the back of the intake valves?  Having a Catch Can would prevent most of the deposits from forming on the intake valves in the 1st place.  

Good question - I'd also like to hear some kind of technical explanation for that, ........might start doing that myself (when the wife's not in the car) if it sounds plausible. 

[handfiler]

7 hours ago, IcyFridge said:

With direct injection, hitting boost will clean those deposits out. Focus ST guys goose it every now and then to cook off the deposits. Driving like a granny all the time builds the deposits more. 

 

Mine should look like new then.

[Perblue]

8 hours ago, IcyFridge said:

With direct injection, hitting boost will clean those deposits out. Focus ST guys goose it every now and then to cook off the deposits. Driving like a granny all the time builds the deposits more. 

 

I don't baby mine and had alot of oil and specks of carbon going through the pcv hose when I put my catch can  at 19000 kms. The thought of that going into the intake and through the motor would still make me want a catch can to prevent and catch any build up that does form whether this is true or not. the amount of build up and how fast it forms in DI engines makes me doubt an italian tune up works with these.

Edited June 17, 2020 by Perblue

[handfiler]

I've been pondering a methanol injection kit for my Mustang to help with reducing the charge air temperatures. It also has some serious cleaning benefits for GDI engines. I should consider it for my Lincoln too.

I'm surprised it hasn't gained more traction.

 

Methanol Injection

[akirby]

20 hours ago, 1004ron said:

 

Good question - I'd also like to hear some kind of technical explanation for that, ........might start doing that myself (when the wife's not in the car) if it sounds plausible. 

It’s not plausible at all for the reason mentioned above - there is nothing in the intake to clean the back of the valves.

[1004ron]

9 minutes ago, akirby said:

It’s not plausible at all for the reason mentioned above - there is nothing in the intake to clean the back of the valves.

That's my understanding, but keen to hear  IcyFridge  explanation.

[omar302]

8 minutes ago, 1004ron said:

That's my understanding, but keen to hear  IcyFridge  explanation.

 

My guess would be due to the high pressure put on the intake system from the turbos would help clean it out. The carbon build up problem in early DI engines were naturally aspirated engines and with EGR systems. Modern vehicles having turbos and with better timing control that replace EGR systems would help reduce carbon build up.

 

Also, engine & intake designs play a critical rule as even some port fuel injected engines suffered carbon build up. But at least with port injection additives could be added to fuel.

[IcyFridge]

On 6/18/2020 at 8:32 AM, 1004ron said:

That's my understanding, but keen to hear  IcyFridge  explanation.

The higher pressures at the RPMs used in the Italian Tune up definitely clear out the carbon deposits. If you gun it, you'll see the smoke come out and after that the soot will diminish over time on the exhaust tips. I know it isn't scientific. I just know that when I was on the Focus ST forums and the Mustang forums, some members swear by it. I tried it and it did make a minor difference for me, so I've been doing it once every two weeks. 

[1004ron]

12 minutes ago, IcyFridge said:

The higher pressures at the RPMs used in the Italian Tune up definitely clear out the carbon deposits. If you gun it, you'll see the smoke come out and after that the soot will diminish over time on the exhaust tips. I know it isn't scientific. I just know that when I was on the Focus ST forums and the Mustang forums, some members swear by it. I tried it and it did make a minor difference for me, so I've been doing it once every two weeks. 

That's right, its not a scientific or technical explanation, and really just assumption that the tailpipe discharge is coming from the valves.

 

At 60K miles on my GDI Sport, on the very few occasions that I've stepped on the gas real heavy there's been no tailpipe discharge, and that's many weeks between such events.

 

The tailpipe discharge is more likely from the Catalytic Converters.

 

[akirby]

2 hours ago, IcyFridge said:

I tried it and it did make a minor difference for me, so I've been doing it once every two weeks. 

It won’t hurt but there is no way you can tell that it’s making a difference unless you look inside the cylinder head at the back of the valves.  This type of buildup on the back of the valves is t coming off with pressure and it builds up very slowly over time and won’t cause noticeable driving issues for years.

[Xtra]

Induction cleaners like that kind that drip or spray into the intake have been known to cause problems with EB engines and can damage the turbos. There is lots of info out there on this subject, but this link gives a  good rundown of the problems with induction cleaners and carbon build-up in EB engines.

 

https://news.pickuptrucks.com/2014/12/induction-service-cleaners-can-damage-ford-ecoboost-engines.html

[Cerberus]

On 7/3/2018 at 5:45 PM, Snox801 said:

Also agree that the cleaner would be impossible to tell. Prob the safest way. I love my meth injection but the plug and play six fueling can be so easily removed that its hot me tempted. Although I didnt get the extended warranty on anything and never had an issue. Plus Ill be out of warranty this year at the rate my wife is driving the thing. Ill have 35,000 in a year. Not bad considering I put on 60,000 a year

Apologies for the thread-jack here, but have you had the opportunity to scope your valves after doing the methanol injection to show how clan they are?

With the DI valve coking issue, i'm considering Meth Injection for a dual purpose of cleaning and charge cooling if i decide to go for a tune at some point..

[Cerberus]

On 6/17/2020 at 6:53 PM, handfiler said:

I've been pondering a methanol injection kit for my Mustang to help with reducing the charge air temperatures. It also has some serious cleaning benefits for GDI engines. I should consider it for my Lincoln too.

I'm surprised it hasn't gained more traction.

 

Methanol Injection

agreed on all. investigating this for exactly that purpose

 

[Cerberus]

On 6/21/2020 at 7:44 AM, IcyFridge said:

The higher pressures at the RPMs used in the Italian Tune up definitely clear out the carbon deposits. If you gun it, you'll see the smoke come out and after that the soot will diminish over time on the exhaust tips. I know it isn't scientific. I just know that when I was on the Focus ST forums and the Mustang forums, some members swear by it. I tried it and it did make a minor difference for me, so I've been doing it once every two weeks. 

no. On a carburated or port injected engine absolutely, blow out the cobwebs on a regular basis.

But on a GDI engine? Higher pressures where? In the combustion chambers? Fair enough, but thats not where the problem lies with DI engines.

The backs of the intake valves don't really see any appreciable pressure, even under max boost (what 15.. maybe 20psi?), so thats not going to have any effect on carbon accumulation unless you have some kind of an abrasive or strong detergent type cleaning medium present.

It is possible that the harmonic vibrations of valve motions high RPMs could actually shake some loose carbon off of them, but anyone who's manually cleaned a valve knows, that will not clean a crusted valve, it just shakes off loose stuff at best.