acheman8

Hey all. Jut wondering if anyone here has installed an oil catch can on their 8th gen. I just purchased one from Mishimoto but they don't provide a model-specific mounting bracket for the Maxima. I have some thoughts on what I'd like to do, but I was looking for additional ideas. If anyone here has installed one, maybe you can share your thoughts and pics. Thanks.

RickSmith

What do you hope to accomplish by installing the oil catch can? Is there a problem with 8 Gen Maximas that an oil catch can will solve and/or prevent?

compyelc4

My question too. I did not know that Nissan had a problem with oil vapors blowing out of the valve covers. Actually, I did not know that the engine even had the old-style PCV system, which would be the main culprit of oil getting into the air intake system.

robtroxel

Absolute waste of money since this is not a hot rod, why bother?

2young2retire

I agree, sounds like a solution without a problem.

Richard66

It's car OEM, so if I add something/anything it will be better.

compyelc4

Huh?! Explain "better" please.

3dogs

An oil catch can is not necessary but does have a preventative maintenance function. All internal combustion engines have some blow by where gases mixed with oil vapor would get past the piston rings and end up in the crank case. Before 1964 they were vented to the atmosphere and if one stood next to a car idling you could smell the blow by.

The PCV valve (positive crankcase ventilation) is a one way check valve that allows gases to be returned to the intake manifold where they are burned in the combustion process. Depending on the design of the PCV system the path of the crank case gases take goes through the throttle body. After many miles oil vapor condenses on the throttle body components because they are relatively colder than the hot gasses. This builds up to the point that the throttle could stick or passages within the throttle body could become partially blocked. A common maintenance item is to clean the throttle body with solvent and a brush to remove this buildup (maybe at 50,000 miles).

I own a 2008 Altima where this problem became so bad that the engine could not start and cleaning the throttle body solved the no-start condition. An oil catch can does just what the name states. It separates the hot oil vapors from the crankcase gasses and stores them in the catch can. The can has a drain valve and when the engine oil is changed the can is also drained.

I installed a catch can on my 2014 Ford F150, 5.0L and it usually has a few ounces of oil in it. I drain the can at each oil change. At 60,000 miles I checked the throttle body and it’s fairly clean and free of oil deposits.

A lot of oil catch cans are junk in that they don’t have anything inside them to allow the oil vapor to condense on. This is easily solved by using a stainless steel pad (used to wash cook ware) and installing it inside the can. Also the location of the can makes a difference in how well it catches oil vapor. If possible it should be installed below the engine where some outside air can cool it. A word of caution—the hoses that go to and from the catch can will be under engine vacuum (depending pcv system design) and should be checked when engine oil is changed to ensure that there are no vacuum leaks.

So is an oil catch can a necessary modification? No, but because many folks that frequent car/truck forums are DIY types it is a fun project that can keep your engine’s throttle body from getting gunked up.

acheman8

The 8th gen Maxima is a GDI engine. As such, gasoline and the competent detergent additives never touch the back of the intake valves. These engines DO have a traditional PCV valve that routes those vapors and oil droplets to the intake. As a result, the intake valves will coke up and affect performance at around 60K miles. If you want to keep those intake valves clean, an oil catch can is one very effective way. Just because the manufacturer did not include one does NOT mean the design cannot be improved upon. Many engine manufacturers acknowledge this problem but figure the warranty period will expire before any real damage is done - thus they are off the hook. BTW -- it is NOT the throttle body that you are protecting... the throttle body does not see any PCV valve emmisions as they are injected directly into the intake well behind the throttle body. The idea is to keep those particulates off of the intake valves.

I purchased a quality piece of kit from Mishimoto that is very well designed and built. I'm kinda surprised that most of the responders to my initial question seem to be uninformed as to the issue and possible solution. Please do some research -- specifically on GDI engines. I promise you that these engines will eventually need MAJOR service ($$$$) for coked up intake valves if you do nothing.

http://www.enginebuildermag.com/2017/10/solving-gasoline-direct-injection-issues-facts-fictions-gdi/
http://lemanpublicrelations.com/gdi-...rd-to-resolve/
http://www.underhoodservice.com/gdi-...intake-valves/
https://www.consumerreports.org/cro/...ines/index.htm
https://www.thetruthaboutcars.com/20...in-a-nutshell/

ChrisMan287

iTrader: (34)

acheman8

3dogs

Found this article about carbon buildup on the backs of intake valves for GDI engines.

Regarding GDI vs. multi-port EFI
The engine is a VQ35DE (V6, 3.5L Displacement and the "E" stands for MPFI). I looked at a 2016 service manual and it says multi-port EFI, fuel pressure 56 psi etc...
Wikipedia states about VQ Nissan engines, "Later versions feature various implementations of variable valve timing and replace MPFI with direct fuel injection (marketed as NEO-Di)."
Do the 3.5L (8th Generation) engines use the NEO-DI fuel system---can't find it anywhere??

compyelc4

"The 8th gen Maxima is a GDI engine."

I'm a little ignorant on this subject. What year did Nissan convert from MPI (multi-port injection) to GDI (direct-injection) on the Maxima? I had no idea my '17 Max had GDI.

acheman8

compyelc4

I thought GDI "bypassed the valves" by directing fuel vapors directly into the combustion chamber.

acheman8

That's correct. That is why the valves foul -- no contact with the gasoline and detergent additives to "wash" them. Read some of the articles i posted...

compyelc4

I read the articles. I was only questioning the previous statement that our Gen8 engines were GDI. I did not think we had GDI, but multi-port injection instead, thus our engines WOULD take advantage of top-shelf fuel additives if this is the case. If the Gen8 DOES have GDI then I need to read up on this potential problem further.

acheman8

I'm not sure when the change was made. Apparently there are three generations for the VQ engine, and the third gen is when they changed to DI fuel system. I THINK maybe for the 2015 or 2016 model year? Anyway, I spoke with the service adviser at my dealer and he confirmed that my 2017 does indeed have the GDI version of the VQ35DE.

My dealership offers an "intake cleaning" where they "inject a chemical into an intake vacuum line behind the throttle body." They offer this service for $179 and recommend it every 10,000 miles. It sounds to me like they are squirting a can of CRC GDI valve cleaner into the intake and charging $179. Haha. No thanks -- I can do that myself for the $15 can of CRC (and I have.) I am just trying to be a bit more proactive with the installation of a catch can.

Richard66

The E on the back of the engine model number VQ35DE stands for "multi port injection system", you would think if Nissan is going to change the fuel delivery system in this car to GDI the letter designation would also change.

acheman8

Not sure that's the case, Richard. I think the E simply means electronic fuel injection - agnostic if it's direct or port. That's my understanding anyway. Do you have a source to validate your claim?

Anyway, my dealership service department verified that my car (2017) has a direct injection engine. I would HOPE they would know, but with dealerships I guess you're taking your chances...

EDIT: Richard, it appears you actually DO know what you are talking about (how refreshing!) I think now that the DE engines ARE port injected and the direct injected engines are designated DD. I had understood the change from port to direct injection on the DE occurred around 2015 or 2016 with no change in engine number. I may have been a bit of a chicken little concerning the need for a catch can on this car. Disappointing that my dealership service folks don't even know the difference...

So, now for my 2018 Infiniti Q60, same question... haha

Richard66

Although this does not answer the question about the fuel delivery system of the VQ35DE I thought it was interesting about the Altima's turbo fuel system. I got this off the Nissan site.


The VC-Turbo engine uses both multi-point injection and gasoline direct injection to balance efficiency and power in all conditions. Gasoline direct injection improves combustion efficiency and performance, and enables the engine to avoid knocking at higher compression ratios.

The multi-point injection system mixes fuel and air earlier, enabling complete combustion in the chamber for greater efficiency at low engine loads. The engine switches between both at regular engine speeds, with both sets of injectors able to work in conjunction under higher loads.

In addition, low-friction mirror bore coating contributes to a 44% reduction in cylinder friction, allowing the engine to rotate more smoothly. The coating is applied to the cylinder walls by a plasma jet, then hardened and honed to create ultra-smooth cylinder walls. And finally, a two-stage variable displacement oil pump raises the oil pressure as engine speeds rise and the compression ratio lowers.

Altimas equipped with the VC-Turbo (SR 2.0L and Platinum 2.0L grades) include a meter in the instrument panel's 7-inch Advanced Drive Assist Display so the driver can see, as well as feel, the control state of this unique technology while driving.

"This advanced new VC-Turbo engine can balance the engine character between economy and high power by accelerator pedal operation only," added Muñoz. "And, with no special maintenance required, drivers can just enjoy the driving experience without thinking about all the amazing things happening under the hood."

*

2young2retire

I'm still confused. After a lot of searching what I found is that the VQ35DE engine is still a MPI. The VQ35DD engine is the GDI.

VQ35DD

A larger 3.5L with direct-injection is released for 2017 model year.
It is fitted to the following vehicles:

• 2017–present Nissan Pathfinder
• 2017–present Infiniti QX60

Let me know if i'm wrong.

Richard66

Engine specs for just about any engine out there.

https://www.engine-specs.net/nissan-engines

Nmax5150

Catch can on a late model sedan? lol.. Absolutely no need for that.. ..

Nmax5150

Best Quote of the thread!

acheman8

Absolutely incorrect. Why do you say that?

Nmax5150

I have owned over 50 cars and trucks.. Have worked on cars many years.. Do all my own work.. There is NO need for a oil catch can on a NA 300 v6 Engine. Why do you feel you need a catch can on a new car? All late model engines pull some oil in the upper intake manifold.. its just the nature of the Pcv.. Now there are uses for a catch can with any pressurized engines, due to increased cylinder pressures and other variables. But we are talking about a Nissan Maxima here. If Nissan thought it needed a catch can, I am positive they would have added one.
Please enlighten me as to why you feel a need for a catch can.. Please don't reference anybody on You Tube or the like..
I want a educated answer.. I assume you have at least 20 or more years experience working with cars and not 20 years old..lol
I have worked on Infiniti's for 10 years in a dealership setting.. I know Nissan VERY well.

acheman8

Gasoline direct injected engines do not wash the intake valves like a port injected engine. Your 20 years experience (riiiiiiiiight), I'm certain, was not on GDI engines. The PCV system on a GDI engine will coke up the intake valves after about 60k miles or so, resulting in poor performance. Do some research. Don't depend on your "experience" (haha) when the technology has obviously passed you by...

2young2retire

Wow. Great information. VQ35DE is not GDI!

Nmax5150

Lol.. Have to love the internet tough guy... Your response speaks volumes . ..LMAO..

acheman8

compyelc4

Absolutely correct. Thinking all day that my '17 Max might have GDI induction has bothered me so I started digging in. Our engines certainly are VQ35 DE, ie- NOT GDI. I'm happy to know this. I also have a Nissan "For Immediate Release" document that I got prior to buying my new Max. It states, "Engine induction system is sequential multi-port electronic fuel injection". As stated here by earlier posts, yeah the GDI engines (my wife's 2014 2.5L Malibu has one) are more prone to having the backs of the intake valves carbon up because the fuel vapor is injected into the engine downstream of the valves so there is no chance for the fuel manufacturer's "cleaning additives" to even reach those suckers. I'll sleep better tonight knowing a "catch can" is of no good use to my engine (esp. the way I baby that engine). And a "catch can" can be a stinker to install anyway, and result in way more maintenance than I care to do in draining that puppy of any condensates that my engine fails to evaporate. One dude indicated he had to drain and spray out his "catch can" every month...jeesh!!! Of course he was driving a huge, honking V-8 truck. To those that think the VQ35 DE engine is worthy of a "catch can", then knock yourself out and enjoy your hobby.

3dogs

I'm the "dude" that has an oil catch can on my "honking V-8 Truck" and the maintenance for installing it is minimal. When I drain my oil I unscrew the drain plug on the catch can and drain out the few ounces of oil into the drain pan. I have never had to take it apart and "spray" it out. One big advantage of installing the can on a honking V-8 truck is that these is way more room in the engine compartment than on my new Maxima--I can actually see daylight between the engine and fenderwells. I don't think that I'll install a catch can on my Maxima--to hard to mount and route the hoses.

acheman8

compyelc4

Wow, what a coincidence. When I read your post elsewhere on the web I had no idea you owned a Maxima too, and are a member here. Congrats on both accounts. What year Max do you own? Yep, them big honkin' trucks have way more room to play in. What about your truck (make/model) would make a catch can necessary... high mileage? run it hard? Ill-designed pcv system? Just curious. First time I ever heard of a catch can, it was recommended for my C4 Vette, which I still own at 55,000 miles. We typically run these hard. Not too long ago I took off the intake manifold to replace a poorly factory-installed gasket and it was surprisingly wet on the intake runners with oil near the PCV input. I can see how a catch can could have caught some of that.

Maxima SR

I have meth injection in my 370Z. Everytime I go into boost I clean my valves.

RickSmith

Generation 9 Honda Accords (2013-2017) have had 4 cylinder engines with GDI, which contradicts your comment "The PCV system on a GDI engine will coke up the intake valves after about 60k miles or so, resulting in poor performance." I did some research. Zero, (0) incidents reported by Honda Accord owners with 4 cylinder GDI engines.

https://www.driveaccord.net/forums/8...di-engine.html

3dogs

I have a 2018 Maxima S. My truck is a 2014 Ford F150 with the 5.0L engine (360 HP and 380 torque) and amazingly gets 19 city and 22 hwy mpg not hauling anything.

Why do I have an oil catch can? There are many posts on the F150 forum about trucks with high mileage with throttle bodies (TB) and intake manifolds that have oil deposits due to sucking in crankcase gasses from the PCV valve. Also owners that had installed catch cans report that even without hard driving they consistently drained 1 or 2 ounces from the can at each oil change (also my experience).

Oil drained from the catch would normally go back into the engine via the stock PCV system to be combusted and I think that most of it does. However, the oil vapors that don’t get re-burned end up sticking to the TB and intake manifold.
Here are some tips on buying and installing an oil catch can. More expensive catch cans are not necessarily the most effective.

Get one that has NPT pipe threads for the inlet and outlet hoses—that way you can change out the hose nipples to match whatever size hoses are used on the vehicle’s PCV system.
Inside the catch can there should be a long tube and short tube. The long tube is connected to the PCV valve and the short one goes to the hose that returns to the intake system. Not all catch cans have the long/short tubes. My cheap can only had two short tubes so I extend one of them using copper tubing.

Next install stainless steel wool (pot scrubber works great—available at a Dollar Store) inside the can. This provides surface area for the hot oil vapors to condense into liquid and be stored in the can.
Avoid the catch cans that have an external oil level indicator. They are unnecessary if you simply drain the can at each oil change. If the can were to overflow between oil changes there is a serious engine problem, i.e., rings, valve seals etc. Also the oil level plumbing is another place that could leak.

I think that the F150 community is more interested in maintenance mods than all-out performance—hence oil catch cans are a topic of discussion. They are inexpensive to install (I spent less than $60) and there is lots of room in the engine compartment. There are F150 guys/gals that are obsessed with engine performance and install ECU chips, stainless steel headers and complete exhaust systems (expensive), catalytic convertor by-pass systems (illegal), hi-performance air induction systems and other stuff. These idiots drag race their trucks and brag about elapse times and top, 1/4 mile speeds—to each his/her own.

3dogs

Each OEM and GDI engine configuration will have different issues with carbon deposits from PCV systems. PVC design, injection and variable valve timing, and other factors will all have an effect on carbon deposits. Just because Honda Accords don’t have this issue doesn’t mean that other manufacturers/engines do not have this problem.

Found this article about carbon buildup on the backs of intake valves for GDI engines.

compyelc4

Thanks for the info. If I were lucky enough to own an F150 I'd be right in there installing the "catch".