New v6 1/2 ton Pickups? Best mpgs?

Keith Tanner said:

NickD said:

I will warn you that the Chevy EcoTec3 4.3L suffers from some reliability issues. Largely carbon buildup and misfires from being direct-injected, as well as valvetrain issues from the Active Fuel Management. Seen a few 4.3Ls with broken rocker arms or collapsed lifters or scored cams, as well as valvestems with carbon deposits the size of gumballs at 35K miles.

Curious - how much of this do you attribute to particular types of use? I know that the diesel 6.7s had DPF problems when allowed to sit and idle for hours. Those who keep their trucks moving found the system much less problematic because it was able to go into regen. Are there similar behaviors on the GDI engines?

I can see how a V4 would be shaky, they're just not a well-balanced design.

Use does affect how soon it happens, but carbon buildup, both on valve stems and in ring lands, is inevitable on direct injection. All the PCV gets cooked onto valve stems without fuel wash to clean it off. And the higher combustion temps cook oil into the ring lands and gum up the rings and burn oil. At least that's my experience with GM 2.4L, 4.3L and 5.3L

frenchyd said:

In reply to singleslammer :

i looked very carefully at Chevrolet. I wanted to purchase a Chevrolet due to the fantastic service I had with mine.  20 years service, 371,000 miles with only $1000 spent on repairs and none of them left me stranded.

Instead I wound up selecting a Ford.  I was able to purchase a Ford for a significantly better deal.  

Ive now owned that truck for almost a year with absolutely no problem. In fact I’ve been extremely pleased with the Ford. It’s done everything I asked of it and returned slightly better fuel mileage than anticipated.  

One option which has proven beneficial beyond any is the Flex Fuel option.  It adds only $100 to the list price and discounts the usual 20% effectively it saves me $10.00 per tank and even discounting the decrease in fuel mileage I still save $5.00  per tank full 

 

And isn't there still a federal tax credit for buying a new Flex Fuel vehicle?

I will vouch for the Pentastar, though mine is in a minivan.

That got me thinking, he wants a light duty truck with a V6 capable of 48" between the wheel wells. You could totally just rock a minivan. I think there is a cargo van version of the Caravan, and you get the same Pentastar and nearly 30 mpg, plus it rides better. If you don't need to tow, or carry really tall things, or gravel, I think that may be a wise choice to investigate.

My dad recently bought a '17 Silverado, 4.3 V6 and 4WD.  He knocks down 23 mpg combined every tank.  I've ridden in the truck, and found nothing objectionable about the V4 or V6 modes.  I'd not heard about the direct injection issues, though.   They do tend to do more long trips, not a lot of heavy hauling.   I joke that my dad "old manned out" his Silvo- it's got running boards and a tonnau cover; they pretty much use it like a car.  A few times a year he hauls mulch, or an 18' aluminum fishing boat with it.   Its funny; mom bought a newer Caddy, and dad bough the Silvo...guess which one they drive more and like better?  

I had been putting some hard thought into one of these pickups exactly like the op is describing in the next few years. On the gm carbon build up issues, is there anything a guy can do to help this? Like the old seafoam through a vacuum hose trick every 10k miles, or does that no longer play well with modern engines and engine management?

In reply to gearheadmb :

I think carbon build up is more a function of how it’s used than anything  Short runs of less than an hour will increase carbon build up  while longer will clean itself off due to the alcohol in modern fuels.  

Carbon build up can be reduced if high alcohol fuel is used. That’s another reason to use E85. Not only is the fuel cost lower it’s also cleaner.  In my case I expect to save over $500 a year using mostly E85.  

10% ethanol is normal 15% is available in some states and E 85 has between 30 & 85 % Ethanol The Flex fuel option eliminates the need to even think about it.   

frenchyd said:

Carbon build up can be reduced if high alcohol fuel is used. That’s another reason to use E85. Not only is the fuel cost lower it’s also cleaner.  

That'll have no effect at all on a direct injection engine.  The areas that carbon up are areas that don't get touched by fuel.  

I haven't owned a 90 degree V6 or likely spent much time in one. It was not cool. I didn't experience v4 mode apparently but that sounds terrible. 

In reply to volvoclearinghouse :

If I could get 24 mpg in real world driving, I would be really happy with that. It was a brand new truck but when I was on the highway the gauge was showing 17 at best. I was driving 65-70 on a slight grade. The 17 included up and down the grade. 

In reply to tuna55 :

I would be totally ok with this except the main reason for the truck is metal pickup that I will be doing several times a month. I need an open top to get it since they put it in with a gantry hoist. 

For the moment, I can just going to set my trailer up to be able to latch down metal and send the wife to get metal. I am not a huge fan of that but she didn't like this idea since it would require a payment. The Dodge is still on my radar. I have seen crew cab v8 tradesman trucks listed at $20k. That is a 6 ft bed but the extra interior would make up for it. I can always set up a strap system. 

How much of your driving does the truck actually need to cover?  Would buying a cheaper, older truck that meets your needs be an option if you only drive it when you actually need the truck?  

Yeah, it doesn't have to be my daily. Most trucks in my area are over priced (IMO) AND rusted out. If I don't sell my Saab and get a loan, I can only throw a couple grand at it and that just gets me a truck full of headaches around here. 

I bought a 2017 F-150 XLT Crew cab short bed with the 2.7 ecoboost.  It's got one long trip (1500+ miles) on it, and shows 5000 miles now.  I'm getting around 22 mpg, but I live in the flatlands of coastal Carolina, where they have to build hills.  I'm easy on the gas, as opposed to my Miata that has full throttle /  no throttle driving modes.  I like the truck.  The ergonomics are a little screwed up, I don't understand why the majority of the infotainment controls are a arms length away.  The shut off mode at stop takes some getting used to, but I don't notice it now.

gearheadmb said:

I had been putting some hard thought into one of these pickups exactly like the op is describing in the next few years. On the gm carbon build up issues, is there anything a guy can do to help this? Like the old seafoam through a vacuum hose trick every 10k miles, or does that no longer play well with modern engines and engine management?

My dealership recommends the BG Fuel Induction services every 30K roughly. It helps dramatically. BG recently came out with a direct injection specific kit that is a bit more pricey but supposedly works wonders. I have seen instances though where the carbon was so bad that we had to yank the heads and send them out a machine shop and have them disassembled and hot tanked and cleaned.

In reply to rslifkin :

Apparently you know something I don’t. 

When I worked on sprint cars that had been burning alcohol even if they used a lot of oil they came apart clean and shiny. Not just the Offenhauser but later the Chevy small blocks.  When I’ve seen alcohol dragsters  they too come apart all clean and shiny at least in the combustion chamber.  

Now to be fair there sometimes was a little build up on the exhaust valve if top cylinder lube or something else was mixed with the alcohol.  

So why is direct injection immune from the cleaning effects of alcohol?   

I’m not saying you are wrong because I haven’t been inside a direct injection chamber.  

In reply to frenchyd :

In reply to volvoclearinghouse :

That is exactly how I thought they worked. Thank you.  I fail to understand where the carbon build up occurs still. 

Unless the fuel spray cools oil somehow.  

In reply to frenchyd :

The carbon buildup occurs in the intake runners and on the backside of the intake valves (not in the combustion chambers).  Not an issue with carbs, TBI or port injection as that gets washed off by fuel.  On a DI system, that area doesn't see fuel.  

Builds up in the intake tract since theres no fuel wash and the pcv is still ran into the intake. The fuel in the cylinder is below wear the buildup occurs.

In reply to rslifkin :

Thanks that makes sense

I'd run an OCC/ separator on any DI engine, particularly turbos.

Dunno why they aren't factory equipped w/ OCC, it would only add one easy step to maintenance schedule. Empty can at oil change service.

I looked over the specs on the Colorado again. This is speaking to me. I imagine I will like driving it a LOT better than a full sized truck. A v6 tow package truck is available in the low 20s. I would have to build a set of supports to either raise metal above the wheel wells or tilt one side up. Either way, I still like the idea of a smaller truck. Maybe I can catch next years clearance sales on something like this. 

In reply to singleslammer :

http://coloradofans.com/forums/

Best GMT-700 site on the net. 

What kind of metal are you hauling, and how much does it weigh?

fasted58 said:

I'd run an OCC/ separator on any DI engine, particularly turbos.

Dunno why they aren't factory equipped w/ OCC, it would only add one easy step to maintenance schedule. Empty can at oil change service.

GM made changes to the valve covers on the LT1/4 engines to reduce oil getting into the intake tract. Sort of an internal oil separator. Time will tell if it works or not.