Steve@Advance
Well-known Member
On Saturday, I posted a question about my 2014 Silverado running poorly. No usual test points, nothing looks familiar...
Thanks for all the replies!
Hobo,NC got me on the right track. It is a GDI (gasoline direct injection) engine. Thanks for the link, it has some really crucial information every owner needs to know!
This is not good news! The GDI engines have a serious design flaw. It's not just GM using them either. The Ford Eco Boost engines are GDI, so are many other light trucks and passenger cars. It appears they are the coming thing for performance, emissions, and economy.
The problem is carbon deposits on the intake valves. Since the fuel is injected directly into the combustion chamber, there is no fuel in the air to keep the back side of the intake valve clean. Burning oil from the valve guide builds up, disrupts the air flow into the chamber causing poor performance. It eventually gets bad enough a large chunk falls off, holds the valve open or gets on top of the piston, damages/destroys the engine!!!
I suspect my truck is in the early stages, enough build up to cause poor performance. Being I just bought this truck last summer, I have no history on it. I bought it from a car lot, but it was a high end lot, not a tote the note. They seemed very conscientious about their sales. They volunteered to replace the windshield because of a tiny chip, replaced the missing spare tire, did a few other minor repairs. I noticed the oil was clean, full, and showed 100% on the life, so I assumed they had done an oil change. But what I don't know is, did they use the correct oil? Or what kind of condition the old oil was in before they changed it?
What I've done:
Today I changed the oil and filter. Went with Mobile 1, 0w-20, Dexos 1 approved, meets what the mfg requires. I cleaned the MAF sensor, cleaned the throttle body, (it wasn't bad), blew out the air filter.
Time will tell if anything improves.
I did find out the only way to check the fuel pressures is with a scanner, which I don't have. I'll either have to get one, or trade this off for an older model.
But, what I want to throw out there, probably many of you, like myself, have one of these engines and don't know it!
It is absolutely essential to use the correct oil, keep it full, and keep it changed!!! If using an oil change service, you will need to be sure they are using the correct oil, or buy your own oil, and watch them put it in!
Also, there is no snake oil cure for this! The owners manual cautions against using ANY oil additives. Fuel additives do no good since fuel never touches the back side of the valves.
The ONLY cure, and it is a temporary cure, is to pull the intake, reach in the intake port, and scrape the carbon out! Some say this needs to be done every 15,000 miles! WHAT A CROCK!!!
If this doesn't improve, anyone want to buy a like new, second owner, low mileage, late model unit with all new parts? Not cheap! LOL
Thanks for all the replies!
Hobo,NC got me on the right track. It is a GDI (gasoline direct injection) engine. Thanks for the link, it has some really crucial information every owner needs to know!
This is not good news! The GDI engines have a serious design flaw. It's not just GM using them either. The Ford Eco Boost engines are GDI, so are many other light trucks and passenger cars. It appears they are the coming thing for performance, emissions, and economy.
The problem is carbon deposits on the intake valves. Since the fuel is injected directly into the combustion chamber, there is no fuel in the air to keep the back side of the intake valve clean. Burning oil from the valve guide builds up, disrupts the air flow into the chamber causing poor performance. It eventually gets bad enough a large chunk falls off, holds the valve open or gets on top of the piston, damages/destroys the engine!!!
I suspect my truck is in the early stages, enough build up to cause poor performance. Being I just bought this truck last summer, I have no history on it. I bought it from a car lot, but it was a high end lot, not a tote the note. They seemed very conscientious about their sales. They volunteered to replace the windshield because of a tiny chip, replaced the missing spare tire, did a few other minor repairs. I noticed the oil was clean, full, and showed 100% on the life, so I assumed they had done an oil change. But what I don't know is, did they use the correct oil? Or what kind of condition the old oil was in before they changed it?
What I've done:
Today I changed the oil and filter. Went with Mobile 1, 0w-20, Dexos 1 approved, meets what the mfg requires. I cleaned the MAF sensor, cleaned the throttle body, (it wasn't bad), blew out the air filter.
Time will tell if anything improves.
I did find out the only way to check the fuel pressures is with a scanner, which I don't have. I'll either have to get one, or trade this off for an older model.
But, what I want to throw out there, probably many of you, like myself, have one of these engines and don't know it!
It is absolutely essential to use the correct oil, keep it full, and keep it changed!!! If using an oil change service, you will need to be sure they are using the correct oil, or buy your own oil, and watch them put it in!
Also, there is no snake oil cure for this! The owners manual cautions against using ANY oil additives. Fuel additives do no good since fuel never touches the back side of the valves.
The ONLY cure, and it is a temporary cure, is to pull the intake, reach in the intake port, and scrape the carbon out! Some say this needs to be done every 15,000 miles! WHAT A CROCK!!!
If this doesn't improve, anyone want to buy a like new, second owner, low mileage, late model unit with all new parts? Not cheap! LOL