[callmeneo]

Originally Posted by Mudhalaipatti

After .....

I can answer and suggest somethings based on my knowledge of a fuel system.

The fuel tank has a valve( there might be more than 1 valve based on the size and shape of the tank) which is called a roll over valve which also helps in breathing of the tank ie when fuel is being filled inside the tank, it lets the air inside the tank to go out which is then routed to the charcoal canister. The charcoal canister has a mechanism to ADsorb(not ABsorb) the hydrocarbons and lets out normal air though the vent line.

When you start filling fuel ,all the valves are open to let out the air/vapor in the tank. When the amount of fuel reaches the prescribed limit, the float mechanism in this valve moves up and closes the hole. This in turn stops fuel from entering the tank as you can fill something(fuel) into a fixed system without removing something(air) from it. This fuel in turn spurts back and touches the sensor in the nozzle gun and then the auto cut off happens.

If the tank does not have enough valves or cant vent out the vapors quickly from the tank while filling , you get a false auto cut off.

Also if the valve system in the fuel tank isn't efficient enough for its size and shape then you can observe it when you open the fuel cap after the vehicle has been out in the sun for quite some time. You get a whooshing sound(due to the relieving of pressure) when you open the fuel cap.

Couple of ways a fuel tank can be overfilled is either though shaking the vehicle which in turn keeps one of the valves open and hence u can keep filling the fuel above its prescribed limit.

Another way is when one of the valve goes bad and in this case ,it lets out both vapor and fuel. Hence please ask the service center to check the fuel tank valves too once.

Now coming back to the canister : once a canister ABsorbs fuel , the charcoal looses it Adsorption property and it can no longer ADsorb the hydrocarbons(HC).

A canister has 3 openings, 1 for the vapor from the tank to go in to canister, 1 connection from the canister to the purge valve and the last opening is to the environment for sucking in the air when the purge valve opens. You can ask the service center for the position of the canister(its either in the rear wheel arch or in the front near the firewall) and corelate if this is where you saw the leak. If yes then the fuel might have leaked out of the canister vent line.

On the topic that the intake manifold could not handle a little bit of fuel and getting clogged due to it, i have doubts on this theory.

Hope i could clear some of the doubts.

[Corvalis18]

Hello Sir, My friend has got a XUV 700 and is facing similar issues. He is from Chennai too. Could you please share your email or any other better way to get in touch with you to get some tips and advice. I am unable to pm you, guess it's because i am a new member to team-bhp.

[impala]

Originally Posted by Mudhalaipatti

Hot off the press - After being parked for nearly 6 hours, I take out the car at 2.30 p.m and the vehicle promptly switches off thrice between 2.30 and 2.45. The last one occurs just as I am merging on to the highway.

Sorry to hear that it has recurred; thank you for keeping the community informed. After I faced this issue earlier this month, I had taken a wait and watch stand despite them not replacing canister, hoping that it won't repeat. Now I see a third owner reporting the issue too later on this thread. I am going to follow up directly with Mahindra instead of relying on ASC now.

Trying to get a pattern - did this happen both time when you did not to drive long enough after the refill? Also, in my case too, like you faced, issue became more pronounced on day 2 which makes me believe canister is getting more fuel in it while parked. I am wondering whether this has to do with parking with full tank. That was the only thing I had done differently other than parking on an incline when I faced the issue. Does anyone think this might be a case of condensation of vapor?

Originally Posted by callmeneo

the charcoal looses it Adsorption property and it can no longer ADsorb the hydrocarbons(HC).

Do you see a risk of canister permanently getting damaged once it's filled with liquid petrol?

Originally Posted by callmeneo

You can ask the service center for the position of the canister(its either in the rear wheel arch or in the front near the firewall) and corelate if this is where you saw the leak. If yes then the fuel might have leaked out of the canister vent line.

It's somewhat near the b pillar, under the chasis if I am remembering correctly what the technician showed me. Marking it on a screenshot taken from a

video

.

[Mudhalaipatti]

Originally Posted by Corvalis18

Hello Sir, My friend has got a XUV 700 and is facing similar issues. He is from Chennai too. Could you please share your email or any other better way to get in touch with you to get some tips and advice. I am unable to pm you, guess it's because i am a new member to team-bhp.

Not able to send an email to you.

Sorry! That user has specified that they do not wish to receive emails. If you still wish to send an email to this user, please contact the administrator and they may be able to help.

[arijitkanrar]

This is saddening to see the issue happening with so many owners of an otherwise great vehicle.

Based on the responses here, I'm just wondering if fuel sloshing has got anything to do with this?
Could it be that fuel sloshing around in the tank after a tankfull somehow finds a way into the hose to the EVAP canister? It might be a possibility if the design of the fuel tank and EVAP canister hose junction somehow allows fuel to be retained in it instead of draining back to the tank itself.
This is primarily based on owners experiences where the problem usually occurs the next day. It would seem that after filling the tank fully, while driving back, the fuel sloshing would cause some of it to enter the EVAP canister hose and stay there. Next day when the vehicle is parked, positive pressure pushes the fuel remaining in the hose to the canister causing all the issues.

It would never happen the same day because the running engine keeps sucking fuel out never allowing a positive pressure to build and never allowing the fuel retained in the hose to reach the canister.

This is just my theory. Please feel free to point out mistakes here. Would be happy to learn.

[callmeneo]

Originally Posted by impala

Do you see a risk of canister permanently getting damaged once it's filled with liquid petrol?


It's somewhat near the b pillar, under the chasis if I am remembering correctly what the technician showed me. Marking it on a screenshot taken from a video.

Attachment 2290458

Yes the coal is pretty useless once its wet with fuel or moisture/water. It degrades and looses its Adsorption property and the canister has to be replaced.

Also the placement of the canister is weird .Usually the canister is placed at/ above the max fuel level in the fuel tank though there is no standard or rule for this. Its just the laws of physics and fluid dynamics. Is the vent line which is open to the surrounding at least at a higher position or location than the highest fuel level??

[callmeneo]

Originally Posted by arijitkanrar

This is saddening to see the issue happening with so many owners of an otherwise great vehicle.

Based on the responses here, I'm just wondering if fuel sloshing has got anything to do with this?
Could it be that fuel sloshing around in the tank after a tankfull somehow finds a way into the hose to the EVAP canister? It might be a possibility if the design of the fuel tank and EVAP canister hose junction somehow allows fuel to be retained in it instead of draining back to the tank itself.
This is primarily based on owners experiences where the problem usually occurs the next day. It would seem that after filling the tank fully, while driving back, the fuel sloshing would cause some of it to enter the EVAP canister hose and stay there. Next day when the vehicle is parked, positive pressure pushes the fuel remaining in the hose to the canister causing all the issues.

It would never happen the same day because the running engine keeps sucking fuel out never allowing a positive pressure to build and never allowing the fuel retained in the hose to reach the canister.

This is just my theory. Please feel free to point out mistakes here. Would be happy to learn.

Usually the baffles in the tank take care of the sloshing issue. Also the only way a fuel can enter the canister line is through the ROV's/vent valves .SO if fuel is entering the vent line, that means the valves are shot or the design of the placement of vent valves are not efficient. The vent valves are placed at the highest position in the fuel tank and a slosh is usually not enough to push the fuel though the float+ spring combo onto the vent line.

[impala]

Originally Posted by callmeneo

It degrades and looses its Adsorption property and the canister has to be replaced.

Is the vent line which is open to the surrounding at least at a higher position or location than the highest fuel level??

Thank you! I shall chase down Mahindra for a canister replacement; ASC was assertive that it does not need a replacement.

I do not know the position of the vent valve but the OP had noted that the leaked fuel was across the front part of the rear wheel well.

[callmeneo]

Originally Posted by impala

Thank you! I shall chase down Mahindra for a canister replacement; ASC was assertive that it does not need a replacement.

I do not know the position of the vent valve but the OP had noted that the leaked fuel was across the front part of the rear wheel well.

Please check if the location of the vent line from the Canister which is open to atmosphere is near the area where the OP observed the leakage. If the answer is yes ,then i believe that the fuel flooded the canister and then came out of the vent line open to atmosphere( if it does not have a one way valve).

[impala]

Originally Posted by callmeneo

Please check if the location of the vent line from the Canister which is open to atmosphere is near the area where the OP observed the leakage.

I couldn't notice anything that looked like a vent except what the OP had also posted as the overflow outlet. I assume, it being fumes, the vent would open upwards and probably not visible from beneath the car easily. I shall check next time I visit the ASC; which I anticipate is soon as Mahindra Customer Care Manager is arranging a check by their tech team.

[Piyush_DT]

Originally Posted by Mudhalaipatti

[b]
2233072[/ATTACH]

[*]The ADRENOX app is a little weird. Sometimes it shows that the headlamps are on, while there are not.[*]I paired my phone once, however there are two phones listed on the screen. Deleting one, actually deletes both and you sendup with nothing
Attachment 2231030[*] Even though my phone is paired and the phone phonebook download is complete, I don't get to see the call history, phonebook or any other useful information.

I am unable to see all details like yours in trip summary. Below are the only details I could see. Am I missing anything or is it because mine is AX5?

Also, we have to manually do fuel entry every time. Right?

[Mudhalaipatti]

Originally Posted by Piyush_DT

I am unable to see all details like yours in trip summary. Below are the only details I could see. Am I missing anything or is it because mine is AX5?

Also, we have to manually do fuel entry every time. Right?

Yes I believe so. AX7 and AX7L get the remote functionality in the App.

And fuel log in the app is ,err, broken. I don't think, this is how it is supposed to work. It get the correct location, price (most of the time), but always indicates 0 and so yes it's manual. However the reason why I think, it's not working as it is supposed to, is because, there's no option to manually add a fuel record. There are at least 4 instances, where the App failed to indicate a new fuel fill event and I can't add it one manually.


Update on the EVAP Issue
After 3 days at the service centre, the XUV is now back and has a new/updated fuel tank, new charcoal canister. I took it out on a 500km run today and the vehicle is running just fine. I'm not going to pass the verdict anytime soon and will observe the vehicle for a few more weeks.

Also as per Mahindra, the clutch noise is a non issue and they adjusted "something" and the noise is now gone.

Interestingly during this marathon 500km run, I had to hard break at least 4 times and the hazard lights automatically came on. Guess, the vehicle determined that to a critical event occurred and turned on the hazard lights.

Brilliant brake setup is all I can say. The vehicle came to a standstill from 120 kmph, with in 100 feet. Well almost. And that too without any drama (no wheel locking, no skidding, no tires screeching). I'm amazed at how this 2 tonne vehicle stops from such such speeds, at such a short time. Guess the tires play a major role in this as well.

This was an interesting trip, in more than one way. Pushed the vehicle beyond it's normal operating range and what a response from the vehicle. This spirited run needs a separate post and will try to post one longish update sooner than later.

[Transmission]

Originally Posted by Mudhalaipatti

Update on the EVAP Issue
After 3 days at the service centre, the XUV is now back and has a new/updated fuel tank, new charcoal canister. I took it out on a 500km run today and the vehicle is running just fine. I'm not going to pass the verdict anytime soon and will observe the vehicle for a few more weeks.

Is it possible for you to confirm visually that the new tank is a new design (as opposed to just a new unit of the same old design)?

Also, do you intend to do your fill-tank, wait overnight, and then get driving test again?

Hope this fixes your issues. It seems to be a really good vehicle in general otherwise

The XUV 700 was once in my list of vehicles shortlisted for a buy but over time it looks lincreasingly likely that it wont be what I eventually buy (even without this EVAP issue). A lack of details on the AWD, a reluctance of the Mahindra customer care to provide details even when contacted, the long waiting period and my own thinking that changed from I need AWD/4x4 to maybe I'll get a 4x4 later and save some money now all are contributors. I still havent made up my mind and am open to cars from the Magnite to the Compass trailhawk (as silly as it may seem).

[Corvalis18]

Originally Posted by Mudhalaipatti

Not able to send an email to you.

Sorry! That user has specified that they do not wish to receive emails. If you still wish to send an email to this user, please contact the administrator and they may be able to help.

I've updated my profile to be able to receive emails sir, I'm however mentioning my email id here mmanoj03@yahoo.com. Thank you

[impala]

Originally Posted by Piyush_DT

I am unable to see all. Am I missing anything or is it because mine is AX5?

I had checked this with Mahindra as I don't see this for AX7 too. Mileage, acceleration, shifts etc. are displayed based on the eco sense feature of the car. It's not available for ATs.