[Jim_001]

At the March 2020 Minneapolis Auto Show, the Frontier product manager and I had a lengthy discussion about this. He claimed that the new engine had some form of dual injection, with just enough part-time port flow to keep the intake valves from coking up. I would love to verify this! Has anyone seen any evidence?

 

[NoSmoke]

Just to be clear, I don’t have much knowledge about engines, or am I a mechanic. I’m just a 30 year old guy who does some occasional DIY and I take care of my truck.

From all that I’ve read, the current Frontier has port injection. And I’m learning that the new 3.8 V6 Frontier will be Direct Injection. I’ve also heard a lot that DI engines are prone to carbon buildup as opposed to others such as... port injection.

in a nutshell, what does that mean long term wise? I know we don’t have a lot of info about the new engine, and aside from that, 9 speed automatics kinda scare me? That’s exactly why I passed on a Tacoma, I felt it had too much brains and not enough instinct.

You have to remember......Nissan, and other car manufacturers, don't build cars & trucks to last, only to sell!

 

[NoSmoke]

At the March 2020 Minneapolis Auto Show, the Frontier product manager and I had a lengthy discussion about this. He claimed that the new engine had some form of dual injection, with just enough part-time port flow to keep the intake valves from coking up. I would love to verify this! Has anyone seen any evidence?

Yeah, I really believe that one! I need to get the smoke out of my A$$ now!

 

[Kelly Mack]

Direct injection is a great idea in theory and definitely does get better fuel mileage...alot better in some cases. The problem is the EGR system in conjunction with the GDI. Constantly circulating spent exhaust gases past the intake valve without fuel to help keep it clean is a bad idea. That's why an EGR valve eventually needs a clean or replace...cuz it cokes up from many miles of only dirty exhaust flowing through it. If there were no EGR system then there would be no problem with GDI intake valves coking up. That's probably the reason why many are starting to go to the port/direct combo to try and keep that from happening.

 

[RyanD1966]

Direct injection is a great idea in theory and definitely does get better fuel mileage...alot better in some cases. The problem is the EGR system in conjunction with the GDI. Constantly circulating spent exhaust gases past the intake valve without fuel to help keep it clean is a bad idea. That's why an EGR valve eventually needs a clean or replace...cuz it cokes up from many miles of only dirty exhaust flowing through it. If there were no EGR system then there would be no problem with GDI intake valves coking up. That's probably the reason why many are starting to go to the port/direct combo to try and keep that from happening.

Not entirely. You forgot about the crap the PCV system deposits on the intake valves, as well. GDI's suck big time, always have, always will. My 2008 Cooper S Turbo GDI was a dumpster fire of an engine, a joint trainwreck between the Germans and the Frenchies. W/o a dual flow system with 12 injectors, this engine'll be just as bad. I'll keep my middlin horrible fuel economy and keep driving what I already have, thank you very much.

 

[Kelly Mack]

Not entirely. You forgot about the crap the PCV system deposits on the intake valves, as well. GDI's suck big time, always have, always will. My 2008 Cooper S Turbo GDI was a dumpster fire of an engine, a joint trainwreck between the Germans and the Frenchies. W/o a dual flow system with 12 injectors, this engine'll be just as bad. I'll keep my middlin horrible fuel economy and keep driving what I already have, thank you very much.

Yeah that too. I agree about the Germans too...anything they touch becomes a dumpster fire. That's all they make is crap. BMW is the absolute worst, Mercedes is trash, VW is a joke, Porsche is the best they can do and it has problems too. Everything that comes out of Germany is a high depreciating pile of trash. I had a BMW X5 Sport before and it was by far the biggest piece of crap I've ever owned. Had to sell it at 50k miles cuz the constant repairs were starting to come out of my pocket.

Every time I hear someone tout 'German engineering' I laugh my arse off.

 

[Manatee Bob]

Who would have thought that I would get a heads up for my GDI C7 Corvette on the Frontier forum and this thread specifically? I was lucky enough to snag a new 2019 V6 port injection Frontier so have less worries concerning carbon buildup on the valve train and other components. However, my 2019 Corvette utilizes direct injection which brings me to an epiphany I had last night. On the Vette, I need to be mildly concerned about carbon deposit buildups due to what I am reading here and other places. So, I also looked up what the best fix is for ameliorating the potential carbon buildup and Techron Complete Fuel System Cleaner with high levels of a chemical (PEA) are considered the best fuel additive to reduce or prevent carbon build up. Supposedly, if used every 3,000 miles, it does the most good so I ordered a six pack of the cleaner last night on Amazon for the Vette. I will likely use it less often in my "old school" Frontier that I am just in the process of breaking in.

I suspect that folks getting the 2020 and beyond 3.8L direct injection Frontiers will want to consider using this product to keep their engines from carboning up?

 

[RyanD1966]

Who would have thought that I would get a heads up for my GDI C7 Corvette on the Frontier forum and this thread specifically? I was lucky enough to snag a new 2019 V6 port injection Frontier so have less worries concerning carbon buildup on the valve train and other components. However, my 2019 Corvette utilizes direct injection which brings me to an epiphany I had last night. On the Vette, I need to be mildly concerned about carbon deposit buildups due to what I am reading here and other places. So, I also looked up what the best fix is for ameliorating the potential carbon buildup and Techron Complete Fuel System Cleaner with high levels of a chemical (PEA) are considered the best fuel additive to reduce or prevent carbon build up. Supposedly, if used every 3,000 miles, it does the most good so I ordered a six pack of the cleaner last night on Amazon for the Vette. I will likely use it less often in my "old school" Frontier that I am just in the process of breaking in.

I suspect that folks getting the 2020 and beyond 3.8L direct injection Frontiers will want to consider using this product to keep their engines from carboning up?

Ain't gonna do squat, pardon my bad English. The Techron ( which by the way I use regularly in all my PORT INJECTED vehicles and have 8 bottles in the garage right now cause AutoZone was running a BOGO ), bypasses the intake valves completely and fires directly onto the back of the pistons. You could use battery acid in your fuel tank and it would do absolutely NOTHING to keep the intake valves clean. The injectors, however, would be sparkling. The fundamental flaw of DI is that the valves never get wetted so it matters squat how much Premium fuel or additives you add to your fuel tank. Nothins gonna happen. Hybrid DI - Port is the only way these engines are ever gonna run right. I'll keep my 2014 port engine til it drops then VK swap it assuming the body hasn't rotted by then, and heavy rust in modern vehicles is quite rare.

 

[Manatee Bob]

Ryan, I think your observation about it not being particularly beneficial for the intake valves is supported by some other comments made on the Internet. Some say that there may be a mild benefit for certain engines based on the intake valve timing events (i.e. Miller cycle). At least my fuel lines, injectors and combustion chambers will benefit in both the port and direct injection strategies with the use of the Techron. The idea posited by a few, about intake valve backwash, seems kind of sketchy to me and like you, I doubt that the PEA will have any substantive effects on the intake valves.

It appears that the CRC product for introducing atomized mist in the intake manifold of a heat soaked engine is the ticket for intake valve carbon deposit buildup on a DI engine as well as port and carbureted engines. CRC has a very detailed YouTube video on the product's application.

 

[TwoWheelsDown]

Ain't gonna do squat, pardon my bad English. The Techron ( which by the way I use regularly in all my PORT INJECTED vehicles and have 8 bottles in the garage right now cause AutoZone was running a BOGO ), bypasses the intake valves completely and fires directly onto the back of the pistons. You could use battery acid in your fuel tank and it would do absolutely NOTHING to keep the intake valves clean. The injectors, however, would be sparkling. The fundamental flaw of DI is that the valves never get wetted so it matters squat how much Premium fuel or additives you add to your fuel tank. Nothins gonna happen. Hybrid DI - Port is the only way these engines are ever gonna run right. I'll keep my 2014 port engine til it drops then VK swap it assuming the body hasn't rotted by then, and heavy rust in modern vehicles is quite rare.

I was about to write pretty much the same thing. But since you already mentioned it, I'll skip that and move onto something else.

GDI coking can be mostly prevented (kicking the can further down the road) by maintaining high heat cycles and cylinder head temperatures. In other words, if you have a long commute and rev the snot out of it occasionally, you will be okay for longer. If you drive three miles (or in the case of one of my coworkers, a hundred yards) each way, well, you wouldn't be doing a MPFI engine much help, never mind a GDI engine.

I'm looking at picking up a Toyota RAV4. Seems like the best long-term reliable option available from the screamin' hot small SUV sector. Every other vehicle is either GDI or turbocharged and GDI. The RAV4 has a carryover 2.5L but now equipped with Toyota's PDI called D-4S.

 

[old greybeard]

Interesting we assume Nissan didn’t pay attention to preventing gdi issues.
Not worried about it. Have just 63k on my GDI Focus, but a ton of them are out there well into 100-300k and haven’t been reading of issues.
Use full synthetic oil, change every 5k. Use quality fuel.
The Mini Cooper motor sucks, poor design. But alot of things suck on the MC’s. I have faith that Nissan’s engineers paid attention.
Many reasons not to buy a new motor/transmission combo. But to me GDI isn’t one of them.

 

[Cgalloni]

The engine is 100% DI engine no hybrid system like Toyota or Ford. Big mistake from Nissan

 

[RyanD1966]

Interesting we assume Nissan didn’t pay attention to preventing gdi issues.
Not worried about it. Have just 63k on my GDI Focus, but a ton of them are out there well into 100-300k and haven’t been reading of issues.
Use full synthetic oil, change every 5k. Use quality fuel.
The Mini Cooper motor sucks, poor design. But alot of things suck on the MC’s. I have faith that Nissan’s engineers paid attention.
Many reasons not to buy a new motor/transmission combo. But to me GDI isn’t one of them.

You haven't been paying attention to current events. Nissan is working with Peugeot, has been for years, and they are now part of the 14 nameplate colossus ( Stellantis ) including Chrysler and Fiat. The BMW MINI Cooper engine was a joint-venture w/ Peugeot and appeared in the 207 Turbo hatchback & MINI Cooper S & John Cooper Works, which means they're all sharing cross-engineering and platform parts. I have very little faith that Nissan engineers paid attention and I won't be purchasing a GDI engine. Ya'all can go roll the dice and let me know how it worked out for ya. I'm done being the "platform engineer" for 80% finished powertrain combinations and let the public fix the other 20%. My trainwreck of a Cooper cost me thousands.

 

[old greybeard]

Lose the attitude dude, dont tell me what I am or not paying attention to. This is about your 10th post whining about buying a poc mini. Not our problem.

 

[vjmvjm]

Interesting we assume Nissan didn’t pay attention to preventing gdi issues.
Not worried about it. Have just 63k on my GDI Focus, but a ton of them are out there well into 100-300k and haven’t been reading of issues.
Use full synthetic oil, change every 5k. Use quality fuel.
The Mini Cooper motor sucks, poor design. But alot of things suck on the MC’s. I have faith that Nissan’s engineers paid attention.
Many reasons not to buy a new motor/transmission combo. But to me GDI isn’t one of them.

If we followed the advice of all the owners of older models complaining about new technology on new vehicles, we'd still be driving around our very first vehicles. Some people are simply afraid of change, and make all kinds of excuses to avoid it. There are millions of GDI engines operating just fine around the world. Some will have issues, but that's the same with any engine, regardless of design.

And don't forget that the 2020s have a plastic transmission pan, and shift too often (from a different hilarious thread). You do know that a plastic transmission pan means you can't haul or tow anything, right?

 

[FFTR]

Plastic transmission pan. Metal skid plate. Problem solved.

Time will tell if DI is going to be a issue. Talked to Mazda mechanic and said that DI can result in carbon build up over time. He has had only a couple of high mileage motors he had to remove the carbon from. Most vehicles have not been an issue.

 

[rdp91356]

Just traded my Subarus Crosstrek with GDI for a 2019 Frontier. I used an oil catch can, used top tier fule and Valvoline Modern engine oil.
I was shocked at home much oil was in the can afytet 2ooo miles.

I have a catch can on my 2018 P4X and catch a shot glass worth of oil (about 1.8 oz) every 1000 miles. Even for a non DI engine I think it's worth it not to have all that oil vapor being fed back into what should be clean air intake.

 

[shift_RUSH]

I have a catch can on my 2018 P4X and catch a shot glass worth of oil (about 1.8 oz) every 1000 miles. Even for a non DI engine I think it's worth it not to have all that oil vapor being fed back into what should be clean air intake.

VQ40 w/o a catch can(?):
Makes sense then that these burnt oil vapors from combustion would send this particulate into our primary cats. For anyone running the wrong oil(s), I could see the possibility of early cat demise.
I recall one older hot rod guy talking up using a high zinc oil in his VQ40...to which I had replied might be a poor decision.
~ Which leads me to wondering out loud that should one have early cat demise prior to 80k (our factory emissions' warranty), might there be some forensic analysis to determine the above scenario and determine fault on the owner?

 

[bajasam]

Don't get the DI panic goin on. Plenty of commercial intake valve cleaning kits for DIY, and even more for professional repair shops. I use the Berryman's kit on my Hyundai, 27 bucks every 30K miles keeps em clean as a whistle, pro mechanic's will clean them for about 200$ with their commercial duty systems, all kits use the same PEA (techron) cleaner.It's only an issue if you choose to not perform preventative maintenance. So relax there chicken little.