Another Mechanic Help Thread

**ehidle** · December 26th, 2009, 04:15 PM

I'm in a bit of a bad place here. April and I are out here in Omaha with a Pathfinder that won't start.

Here's what I know.

1) It has been damn cold here. My first thought was maybe water in the gas getting frozen. I added 3 pts of dry gas and we managed to push the truck into the heated garage. We've thawed the truck out with a 55kBTU kero blower... still won't start

2) After 1500mi, there seems to be a serious lack of oil in the crankcase. There's just a tiny bit showing on the tip of the dipstick, meaning it's about 2 to 2.5qt low. This is alarming, since I just changed it before our trip, and there's no sign of leakage around the filter or drain bolt. There is also no sign of any other leaking - at least none that makes it to the ground. I'm really worried about this.

3) The problem is fuel starvation. We can get the engine to fire up with some Ether. So, we know the spark is good. Whether the fuel pump is bad or it's still frozen, I don't know.

4) We drove it yesterday with no problems, but in deep deep snow. I also just filled it with gas yesterday while we were out. It was a busy gas station that probably gets 2-3 deliveries per week, so I would think it's not bad gas.

I'd appreciate any commentary about my fuel issue and my magical disappearing oil.

**fingers80002** · December 26th, 2009, 04:29 PM

Sounds like a fuel pump issue, for the starting part.

The oil consumption, could be a PCV issue, some Fords had an Icing issue in Cold weather. Don't know about Nissans.

Take it for what it's worth, I'm just a stupid mechanic.........

**ehidle** · December 26th, 2009, 04:40 PM

Originally Posted by fingers80002

Sounds like a fuel pump issue, for the starting part.

The oil consumption, could be a PCV issue, some Fords had an Icing issue in Cold weather. Don't know about Nissans.

Take it for what it's worth, I'm just a stupid mechanic.........

A little google-fu revealed that there is indeed a design flaw with the right-side valve cover that causes oil to be trapped in the baffle and sucked down the intake. People have reported 1qt every 1k miles, which is exactly what I am seeing. The solution is to replace outright the right-side valve cover and upper and middle intake gaskets. It takes about 4 hours, but solves the problem for another 50k miles or so until it gets crudded up again. People have tried simply cleaning it, but given the labor involved, it's better just to replace it.

Anyway, I agree that it's definitely a fuel delivery issue w/r/t the starting thing. Since we can get the engine to fire with some Ether starting fluid, that eliminates the other usual suspects like ignition and compression and timing belts and sensors and all kinds of other crap that could go wrong.

I guess time will tell with some more thawing in the garage. There's all kinds of ice packed up on the underside of the truck from yesterday's romp in the deep snow. I just would have thought it would start by now... if we don't get it started by the end of the day, we'll yank the fuel pump and see if it's working...

**Hawk** · December 26th, 2009, 04:57 PM

Fuel filter?

**fingers80002** · December 26th, 2009, 05:00 PM

Originally Posted by Hawk

Fuel filter?

Would have given symptoms, before clogging.....

**ReconLdr** · December 26th, 2009, 05:03 PM

Originally Posted by ehidle

I'm in a bit of a bad place here. April and I are out here in Omaha with a Pathfinder that won't start.

Here's what I know.

1) It has been damn cold here. My first thought was maybe water in the gas getting frozen. I added 3 pts of dry gas and we managed to push the truck into the heated garage. We've thawed the truck out with a 55kBTU kero blower... still won't start

2) After 1500mi, there seems to be a serious lack of oil in the crankcase. There's just a tiny bit showing on the tip of the dipstick, meaning it's about 2 to 2.5qt low. This is alarming, since I just changed it before our trip, and there's no sign of leakage around the filter or drain bolt. There is also no sign of any other leaking - at least none that makes it to the ground. I'm really worried about this.

3) The problem is fuel starvation. We can get the engine to fire up with some Ether. So, we know the spark is good. Whether the fuel pump is bad or it's still frozen, I don't know.

4) We drove it yesterday with no problems, but in deep deep snow. I also just filled it with gas yesterday while we were out. It was a busy gas station that probably gets 2-3 deliveries per week, so I would think it's not bad gas.

I'd appreciate any commentary about my fuel issue and my magical disappearing oil.

I have seen quite a few imports (Nissans/VW mainly) with Ice chunks inside the fuel system. I would let it sit inside the heated garage a little longer and see if that helps. The dry gas will help prevent it it from freezing again, but won't thaw out the system if it is already frozen. If it will run on ether or starting fluid, I would guess the fuel pump is not providing fuel.

For the oil consumption, it is not uncommon for a modern engine to consume 1 qt of oil per 1000 miles. It is also very possible the PCV system is "gunked" up and the effects are exagerated by the low temperatures. I would check to see if the PCV system is working when you get the truck running. You can check this by removing the oil fill cap (engine running) and lay a piece of note book paper across the hole. (you may need to trim the paper) The paper only needs to be an inch or so larger than the hole. If the paper sucks fast to the valve cover(or where ever the fill is) the PCV system is working.

**-JD-** · December 26th, 2009, 05:24 PM

Originally Posted by ReconLdr

For the oil consumption, it is not uncommon for a modern engine to consume 1 qt of oil per 1000 miles. It is also very possible the PCV system is "gunked" up and the effects are exagerated by the low temperatures. I would check to see if the PCV system is working when you get the truck running. You can check this by removing the oil fill cap (engine running) and lay a piece of note book paper across the hole. (you may need to trim the paper) The paper only needs to be an inch or so larger than the hole. If the paper sucks fast to the valve cover(or where ever the fill is) the PCV system is working.

Just be sure it doesn't suck-in

**ehidle** · December 26th, 2009, 06:27 PM

The truck finally started after another hour or so in the garage with the heater blowing underneath.

The oil consumption problem seems to be ubiquitous to the VQ35DE Nissan engine. The valve covers are designed in a way that the oil tends to drop deposits into the baffles, which causes a lot of oil to be sucked into the intake system. There's a good writeup of this problem here:

http://www.netcrafting.com/car_mx/pathfinder/oil.html

Anyway, I'm going to let the truck "refreeze" tonight. If it starts up okay in the morning, I'll declare victory.

When I return to Philadelphia, I will worry about the oil consumption problem, and probably fix it by buying a new car.. hah..