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Re: Analysis Paralysis
Posted: Fri Dec 21, 2018 8:59 am
by tabasco122
[quote=""DCIV""]Carbon build up on direct injection is way over built up. I have dont a ton of reading on it, get on the vehicle every once in a while to blow it out, use a fuel additive some, and I've seen people take apart heads with 200k plus on them and the carbon build up is find on direct injection. Really Really blown way out of proportion.
Coop[/quote]
Please tell me how a fuel additive is going to clean carbon deposits on the intake valves when the fuel is injected past the intake valves into the cylinders directly?
Re: Analysis Paralysis
Posted: Fri Dec 21, 2018 10:21 am
by DCIV
[quote=""tabasco122""]Please tell me how a fuel additive is going to clean carbon deposits on the intake valves when the fuel is injected past the intake valves into the cylinders directly?[/quote]
Call me crazy but the carbon is created from the burning of the fuel...the same fuel with the additive, so it would go with the carbon. Litterally everything Ive read is to add in Techron or simialar every so often. But again, I think its an issue blown way out of proportion.
Coop
Re: Analysis Paralysis
Posted: Fri Dec 21, 2018 3:15 pm
by vr4
[quote=""tabasco122""]Please tell me how a fuel additive is going to clean carbon deposits on the intake valves when the fuel is injected past the intake valves into the cylinders directly?[/quote]
[quote=""DCIV""]Call me crazy but the carbon is created from the burning of the fuel...the same fuel with the additive, so it would go with the carbon. Litterally everything Ive read is to add in Techron or simialar every so often. But again, I think its an issue blown way out of proportion.
Coop[/quote]
The carbon buildup is from many things. Heat, valve timing to replace egr use, oil vapors.
The fuel never touches the back side of the valves where the carbon buildup issue is.
Re: Analysis Paralysis
Posted: Sat Dec 22, 2018 4:54 am
by tabasco122
carbon on the intake valves is from blowby from the PCV system and crankcase.
Re: Analysis Paralysis
Posted: Sat Dec 22, 2018 11:44 am
by DCIV
Then why do non turbo direct injection have the same issue they shouldnt have any blowby.
Coop
Re: Analysis Paralysis
Posted: Sat Dec 22, 2018 3:58 pm
by vr4
[quote=""DCIV""]Then why do non turbo direct injection have the same issue they shouldnt have any blowby.
Coop[/quote]
All engines have blow-by
Re: Analysis Paralysis
Posted: Sat Dec 22, 2018 5:03 pm
by DCIV
[quote=""vr4""]All engines have blow-by[/quote]
Lol yes. All engines do, but with an issue thats made into something so big, turbo engines magnify this though.
Have you actually had a vehicle with direct injection get bad enough to cause it to run poorly or not at all?
Coop
Re: Analysis Paralysis
Posted: Sat Dec 22, 2018 7:17 pm
by vr4
[quote=""DCIV""]Lol yes. All engines do, but with an issue thats made into something so big, turbo engines magnify this though.
Have you actually had a vehicle with direct injection get bad enough to cause it to run poorly or not at all?
Coop[/quote]
I've had them in the shop, yes.
I own nothing with GDI
Re: Analysis Paralysis
Posted: Sat Dec 22, 2018 7:29 pm
by DirtyRyda
I've seen some pictures of some pretty nasty looking valves on the Cobalt forums. A lot of people have walnut blasted theirs and Powell Race Parts makes a oil separator that returns the oil to the pan to prevent future buildup.
Re: Analysis Paralysis
Posted: Sat Dec 22, 2018 7:48 pm
by Chris GTO TT
Yeah an AOS is recommended for the EcoBoost trucks pretty frequently.
Re: Analysis Paralysis
Posted: Sun Dec 23, 2018 3:42 am
by aaronatstate
I really need to get a catch can for my ST and Ashleys Explorer.
Re: Analysis Paralysis
Posted: Sun Dec 23, 2018 6:14 am
by tabasco122
I have pictures of my 335i somewhere that I walnut blasted
Re: Analysis Paralysis
Posted: Sun Dec 23, 2018 6:25 am
by tabasco122
Actually, i just have pics midway through, my car was way worse than this, only 60k miles on it at the time.
http://my1series.com/2014/04/28/finally ... s-cleaned/
this is one of mine after the first round, you can see that there is still tons of carbon on the top of the valve, you cant even see where the valve meets the head, its just crud on top of it. took quite a bit of work to get them all clean like the pictures on that guys blog.

Re: Analysis Paralysis
Posted: Sun Dec 23, 2018 1:10 pm
by DirtyRyda
I have 135k on my Cobalt and I'm guessing they've never been cleaned. I don't have a place to do it myself. Hopefully will be getting a different DD by spring and gonna try to find some one that can do it for a reasonable price.
Re: Analysis Paralysis
Posted: Sun Dec 23, 2018 5:22 pm
by aaronatstate
Im gonna need to do this soon on the ST. At least check it. Going to buy the catch can when I get back after Christmas.
Re: Analysis Paralysis
Posted: Fri Dec 28, 2018 10:54 pm
by Chris GTO TT
We went back to look at the F150 today, they still had it after our trip by some miracle, and the exterior was far rougher than I was willing to deal with. Also noticed it had been backed into or hit bu something because the rear bumper was tweaked on the passenger side. It hit whatever it was hard enough to cause the corner of the bumper to tear the sheet metal behind the bumper. When I first looked at the truck it was dusk so I couldn't really see the damage. Combined with being uneasy with the timing issues on the 3.5TT and them wanting $3600 for a 2 year 24k service contract I walked away.
As much as my wife wants me to just buy a car she agreed with the decision to not buy it. Some of the other things I walked away from you could tell she was ready to hit me lol.
Re: Analysis Paralysis
Posted: Fri Dec 28, 2018 11:59 pm
by ChargerX3
Good choice. Might as well be in sound condition. Plus I know you want a V8
Re: Analysis Paralysis
Posted: Fri Jan 04, 2019 8:57 pm
by Chris GTO TT
I can't win for losing

Found a 122k mile 04 Land Cruiser gray on gray (boring but at least not tan on tan like a lot of them) at a local new car dealership. Make contact with a sales person I've talked to there before. Apparently they are wholesaling it even though they have it listed on their website for sale :d oh:
Re: Analysis Paralysis
Posted: Fri Jan 04, 2019 9:22 pm
by tabasco122
thats what happened to our sti, it went to auction, nobody bid on it, so it came back. They refused to pull it from auction for us
Re: Analysis Paralysis
Posted: Tue Jan 08, 2019 6:25 pm
by ChargerX3