What is wrong with my G

[G'd up]

I have been out of town since for the last 4 days . Before i left i filled my car 3/4 with chevron gas. Then parked it in the driveway. It sat outside in GA weather where it has been 60 during the day then drops down to 30 at night.

This morning i went to start the car and it made a very funny noise. it knocked very hard, missfired, and would not turn over. i tried a couple of times and only got smoke. It wasnt untill i started the car and gave it gas and held it steady to keep an idle. the car poured smoke for a minute then eventually cleared up. I drove it for about 30 mins and now it runs fine.

What do you guys this could be the problem from this???

[marlin29311]

Have you had any prior issues?

You may have had water in the line...

[Focusedintntions]

could have been water or soemthing else that settled in the tank or separated after sitting for so long w/o sloshing the tank.

[G'd up]

hey guys . ive never had this issue before. i figured it was from water in my tank. but i wanted to see if anyone else here has had that problem

[BrandAidDesignG35]

Has it happened since then? Did you fill with supreme 91+ octane?

sometime gas can be bad too... Let us know how you make out next start up.

[Jacko3]

The longest I have let my G sit in my garage is 2 days, at least as far as I can remember. Any longer, and I will go totally crazy.

It may not be bad gas and it may not be even water, as you so feared. If you had water or bad gas in your tank, when you gased up, it wouldn't take more than 5 minutes for you to see the severe and horrible effects of these substances on your G, especially on your way home. The G is very sensitive to gas and water, and it does not take sitting it for 3 days to know this.

My experience is that the G-35 does not like to be left sitting for too long and it does not like to be driven gently and normally. It seems the longer it is let to sit, the more the car cools and contracts back to its pristine state---this is where and when all its problems suddenly emerge. And the nicer you drive the G, the more annoying problems you will have with it in the future. The G-35, hypothetically speaking, was built with an unusually high expansion and contraction allowance/tolerance, which is partly responsible for many of its unusual sounds and behavior. I beleive this was done to aid in its impressive reliability, especially as it ages. Yes, I can confirm that the G-35 gets better and easier to drive as it ages. The gear shifting is so smooth, sometimes I wonder if I am actually driving or playing with a video game joystick.

In the southeast, it would probably take more than 36 hours or more for the G to completely cool and give off all its heat. The G does store a lot of heat and for very lengthy periods--another interesting ability of the car, and a reason why it does not get tired after many hours of flogging, though performance may suffer a little bit.

So, it is possible that you don't flog your G hard enough to remove gum from oil or other substances accumulating inside your engine or fuel system, so that when the G is completley cooled, those gums stick very hard inside your internals, making it hard for fuel to move around normally once it cools completely (36 hours or more of sitting). And the unusually high expansion and contraction allowances/tolerances designed into the G-35, may even be aiding in that effort.

Let me give you an imaginary comparison--the VQ35 DE enine is like building a house with wood and rivets---it creeks and makes all sort of sounds when it is contracting and expanding and it has inefficient spaces that allow for heat and cold to pass through, while the VQ35HR engine is like building a house with concrete and steel--more efficient in removing heat and cold, thus its higher power output, but has slightly less tolerance for abuse than the VQ35DE.

So, start flogging your car and start making it well and happy. An unflogged G-35 is a G-35 that will soon die of sickness and plague.

[C-Kwik]

It may not be bad gas and it may not be even water, as you so feared. If you had water or bad gas in your tank, when you gased up, it wouldn't take more than 5 minutes for you to see the severe and horrible effects of these substances on your G, especially on your way home. The G is very sensitive to gas and water, and it does not take sitting it for 3 days to know this.

Any water that were to be injected out of the fuel system into the motor is not going to have any adverse effects. First, the amount would be quite small (about as much as the amount of fuel that would be injected during startup). Secondly, it will be highly atomized by the injectors which will immediately cause some of the water to start to evaporate. Third, once in the cylinder, as the piston compresses the mixture of air and water, any water still in liquid form will be very quickly atomized due to the heat generated by the compression. Lastly, if you have any doubts, consider that many tuners use water injection in motors to actually help reduce heat inside a combustion chamber. And outside of the great cooling properties, water injection provides to a mixture, it also tends to clean the inside of a cylinder. Water can of course be dangerous in large amounts as a cylinder full of water can't compress and can cause hydrolock. If the engine is running fast when this occurs, you can quickly destroy pistons and rods. But nowhere near that much water is being injected.

My experience is that the G-35 does not like to be left sitting for too long and it does not like to be driven gently and normally. It seems the longer it is let to sit, the more the car cools and contracts back to its pristine state---this is where and when all its problems suddenly emerge. And the nicer you drive the G, the more annoying problems you will have with it in the future. The G-35, hypothetically speaking, was built with an unusually high expansion and contraction allowance/tolerance, which is partly responsible for many of its unusual sounds and behavior. I beleive this was done to aid in its impressive reliability, especially as it ages. Yes, I can confirm that the G-35 gets better and easier to drive as it ages. The gear shifting is so smooth, sometimes I wonder if I am actually driving or playing with a video game joystick.

While pistons AND cylinders do contract and expand with temperaure, I've observed no signs from any VQ that this is outside the realm of any other OE motor. Frankly, the blowby when cold would probably be too high when cold for any manufacturer to consider using materials with an expansion rate that is significantly higher than the block's expansion rate. If you actually hear piston slap out of a stock VQ, its more than likely a sign that something is seriously wrong. And to be sure, I highly doubt that Nissan/Infiniti is using the kind of forged pistons provided by many aftermarket piston manufacturers that would exhibit such a high expansion rate. There is no need for that much strength in stock form.

In the southeast, it would probably take more than 36 hours or more for the G to completely cool and give off all its heat. The G does store a lot of heat and for very lengthy periods--another interesting ability of the car, and a reason why it does not get tired after many hours of flogging, though performance may suffer a little bit.

Once any water-cooled motor gets up to its normal operating temperature, it no longer absorbs any more heat. It sheds it through the cooling system. Short of a failure in the cooling system or am ambient condition causing it to be difficult to shed as much heat as it takes in, this holds true. Also, I don't see any problem with an aluminum engine block being able match its temperature with the ambient temperature within half a day. Given aluminum's low specific heat, low density, and its ability to transfer heat quickly, I'd say even half a day is pretty generous...

So, it is possible that you don't flog your G hard enough to remove gum from oil or other substances accumulating inside your engine or fuel system, so that when the G is completley cooled, those gums stick very hard inside your internals, making it hard for fuel to move around normally once it cools completely (36 hours or more of sitting). And the unusually high expansion and contraction allowances/tolerances designed into the G-35, may even be aiding in that effort.

The main component that causes issue within a motor's crankcase is water. Burning it off does not necessarily require hard driving. Long trips will heat up any water for a long enough time for it to evaporate. As far as the fuel system is concerned, it will take a while before it starts to gum things up. Keep in mind, I kept my motorcycle parked for about 2 weeks due to weather. It started up just fine. The GF's bike, also started up fine. Even the Vulcan I have started up fine after being parked for 2 months since the last time I ran it. The last 2 bikes are carburated and would be much more sensitive to fuel gumming up than a fuel injected motor.

Let me give you an imaginary comparison--the VQ35 DE enine is like building a house with wood and rivets---it creeks and makes all sort of sounds when it is contracting and expanding and it has inefficient spaces that allow for heat and cold to pass through, while the VQ35HR engine is like building a house with concrete and steel--more efficient in removing heat and cold, thus its higher power output, but has slightly less tolerance for abuse than the VQ35DE.

An engine's higher putput is going to be most dependent on its ability to pump air. Larger displacement motors naturally have a higher capability to move more air per revolution. Higher revving motors can fit more revolutions into a given time interval. And increased volumetric efficiency will help a motor fill its cylinders more completely. Things like reduced friction are not going to contribute a large amount of additional power. Increased compression will increase the combusted mixtures expansion ratio which will be more efficient at turning the heat and pressure into mechanical energy. But even then, its somewhat limited. Any efficiencies in removing heat will only make it possible for the conditions to be controlled correctly so that everything else works as it should. But it has no direct impact on the power the engine makes itself.

[SteveTheTech]

This sounds like a pretty common incident to some part when an earlier G sits for an extended period of time they let you know they dislike being left to sit.Rich (SVTCobra) recently had his timing chain tensioners replaced for an extended knocking noise, and I can tell you from first hand experience that that is a very different noise. I'm really not sure but I would guess it's more along the line of the lifters bleeding down over time. This seems to happen more when the temperature swings a pretty decent amount over an extended period. Then there are some that I have seen sit for two months and startup with only a <2second tick (as oil pressure reaches the heads and valvetrain) and it immediately jumps into open loop fast idle.

Working at a dealer we have cars that sit for months in stock and some service cars get left with us for extended periods of time. Upon startup they tend too shake a and make noise for <10 seconds. Now all instances are not the same and if you experience any other driveability concern I would say to get it taken in and looked at. I am thinking in your case your battery's reserve capacity might be getting low. If the voltage drops and the MAF sensor or other engine sensor signal voltage may be incorrect. Or the ECM might not have had enough power to fire up correctly. I would get the battery/charging system tested sometime soon.

[G'd up]

yeah it almost seemed like the electronic system was acting up. smoke, wierd smells, loud knocking, missfiring. But it hasnt done it since so i guess it was the period from sitting.

[smockers83]

Then there are some that I have seen sit for two months and startup with only a <2second tick (as oil pressure reaches the heads and valvetrain) and it immediately jumps into open loop fast idle.

Mine starts right up every time I start her up for the first time after storing her for the winter. It's all about how you let it sit, but after a few days...that's a little strange I must say.

If it is indeed water in the system, get a gas additive that removes the water.

[Jacko3]

C-Kwik:

Nice contribution. However, do you know of anyone who has opened up the revised VQ engine?? It feels different from the original engine. I am doubtful that the piston and rods are the regular type. That engine is unebeleivably strong. I think they changed a lot of things beyond the rings, in the revised VQ engine. What do you think? Oh, and of course, my write up was based on my driving perspective.

[C-Kwik]

I'd expect to see slightly stronger rods (more material, not a stronger/different material), and possibly a more robust piston to rod connection as the rev-up VQ has a higher redline (which means higher tensile loads at the additional RPMs). But outside of that, I doubt there will be any significant change to the bottom end. The rev-up motor makes more power by simply revving higher and breathing better. Frankly, even if stronger materials were used in the pistons and rods, it would add no additional power to the motor. At best, if it were lighter, it may remove some of the parasitic loss with having to accelerate more mass, but I don't see Nissan/Infiniti going with a more expensive material as it would drive up the cost of the motor. Given they already added new components to the top end and perhaps some minor changes to the bottom end, its probably already more expensive to build than the non-rev-up VQ.