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Nissan X-Trail T30 2.2 dCi 4x4 Manuell
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Discussion Starter · #1 ·
First of all, hi guys! I bought a T30 diesel 2004 a few months ago. I have been trying to sign up on the old site for sometime now and today I found out that I could finally register and the site get a nice facelift, the very same day that I found a major problem on my T30.

So, I am going on a long trip of 4000km tomorrow but to my horror woke up to this in the morning under the car:

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It looked like that my right fuel tank is leaking, so I took a look at the other side to compare:

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The other side looked quite normal with dry dirt only so I thought it must have been a leak on one side only. So I remove the rear seats and accessed the fuel tank, and this showed up, filled with diesel, muds and debris:

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For comparison, the other one looked quite dry and normal:

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And it looks like this after I lifted the pump up on the leaked side:

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Not sure if it is normal but the tank is surprisingly full as I had by then driven around 100km by then after the last refill. I wasn't able to open the other pump ring so check the level on the other side. One clue, perhaps relevant, is that the fuel gauge is consistently on the max and rarely moves. In fact, I have never seen the gauge indicator going below the max line. Albeit I have never driven above 150km without refilling. Another clue is that the car has a rough idle (with a perfect RPM, stops shaking only when it is above 1000RPM and moving). So perhaps something is blocked so the pressure builds up in the tank and leaks fuel?

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After spending some time on this, I came up with two possible explanations for the leak, not sure if they are good enough:

1. Fuel pump lock ring not properly tightened.

What I have done: When I opened the fuel pump lock ring on the leaked side, I noticed that it didn't require much effort to open up (I thought I needed a hammer and a pry bar to tap it) so I guess maybe it simply could be that the lock wasn't tightened up properly? I cleaned up the mess and drove it around for 30min with the lock open (not the pump) and it hasn't leaked so far.

2. Fuel tank not equalized, fuel only being pumped on the working side?

What I have done: I thought that it could be the vent tubes that are blocked but I haven't been able to gain access to that area with my hands. Not sure how much it'd help. I open the refill hole and it didn't help with equalizing.

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Since this is my first car so I have quite limited experience working with cars in general, so my question to you guys is that:

1. Do you think it is a good chance it'd survive a long trip of 4000km as long as it no longer leaks from the top?
2. As I really need to get on that long trip tomorrow, what precautions I should be prepared for if the condition worsens somehow?


Thank you very much!
 

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2002 Nissan X-Trail T30, 2.0 SE+
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From the underneath I thought someone had punctured your tank and drained fuel out. But I guess the seal from the pump may have gone, not sure if it was loose. Are you over filling the tank past when it clicks as this also puts more pressure on the sealing ring around the pump. I would have bought a new rubber seal and go from there. There is a possibility the pump on the dry side has also failed previously by the bodge job wiring. Could be why your gauge does not move.
 

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Nissan X-Trail T30 2.2 dCi 4x4 Manuell
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Discussion Starter · #3 ·
From the underneath I thought someone had punctured your tank and drained fuel out. But I guess the seal from the pump may have gone, not sure if it was loose. Are you over filling the tank past when it clicks as this also puts more pressure on the sealing ring around the pump. I would have bought a new rubber seal and go from there. There is a possibility the pump on the dry side has also failed previously by the bodge job wiring. Could be why your gauge does not move.
Thank you for your help. It looked quite scary from the underneath as it is the only part that is relatively "clean and shiny". I will order some new seals, good idea. Do you use hammer to tightened the locker ring or just by hand?

Regarding the fuel pump wiring on the dry side, out of carelessness, it was me that accidentally pulled the wire on the white plastic part but I fixed it right away and it didn't help with the gauge issue.
 

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2002 Nissan X-Trail T30, 2.0 SE+
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Thank you for your help. It looked quite scary from the underneath as it is the only part that is relatively "clean and shiny". I will order some new seals, good idea. Do you use hammer to tightened the locker ring or just by hand?

Regarding the fuel pump wiring on the dry side, out of carelessness, it was me that accidentally pulled the wire on the white plastic part but I fixed it right away and it didn't help with the gauge issue.
I have never done an X-Trail fuel pump, but on other cars I usually use the dedicated tool or a hammer and flat blade screwdriver to loosen the locking ring.
As for the right tank, check the voltage going to the pump wires to see if anything is going to it. If it is getting voltage it could well be the pump is gone.
 

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Nissan X Trail Columbia 2.2 DCi 2006
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Hello and welcome, at last, to our friendly little community.

Firstly, the diesel exy doesn't have a pump in the tank. Fuel is drawn from the tank by the high pressure pump on the engine. I suspect the plastic ring has been cross threaded at some point, hence the leak. Incidentally, that sender unit doesn't operate the fuel gauge, at least not directly. It is there to tell the ECM how much fuel is in the right side of the tank. This then controls a fuel transfer pump which pumps fuel into the left side of the tank. The sender in the left tank sends level signals to ECM and the fuel gauge.

The fuel transport pump is prone to failure. Failure would explain why the right side of the tank is full.

You are probably only using fuel from the left side of the tank, which would mean your range will be greatly reduced. Not a problem as long as you are aware and have enough fuel to reach a filling station.
 

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When you re-fit the ring, spread some silicone grease (Or a tiny bit of vaseline -grease)on the threads as will help tighten and seal ,they are awkward to do at the best of times .Colster hit the nail on the head above with a good write-up.
 

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2002 Nissan X-Trail T30, 2.0 SE+
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It appears the setup is a little similar to the 2.7TDi on the Terrano
 

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Nissan X-Trail T30 2.2 dCi 4x4 Manuell
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Discussion Starter · #8 ·
Thank you all for the help, I have just come back from my long road trip and have some updates:

The fuel leak problem was caused simply by a loosen fuel pump locker ring. I tightened it first by hand and then with a flathead and a hammer for half of a circle and it hasn't leaked since.

Additionally, I was wrong with my hypothesis that the left and right fuel tanks didn't equalize because the fuel gauge didn't move. I proved this by intentionally driving it until the tank went empty, and when I did my refill, it took 57L which seemed correct as the tank is of 60L.

I also found out why the gauge didn't move. When the car went to a halt at an empty tank, the fuel gauge died at the 20% white line which lets me think that the gauge simply needs an "adjustment" of 20% negative offset. So when I wrote that the fuel gauge didn't move after the first 100km, in reality it was perhaps actually at 100%-120% because of the 20% positive offset making 120% the full tank.

Anyways, this old boy hit 400,000km during this long trip and survived without any additional problems and seems to be going strong still, very happy about it!
 
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