| wa4qfy |
This past week I have started to notice a surging when I acceleration hard. It seems
like above about 20K rpm, the engine will start jumping up 10k rpm's, then back down, then back
and forth, and the MO will accelerate matching the engine rpm's until I let off the gas.
If I accelerate slowing it seems that does not exhibit this issue (so far).
Does this sound like a CVT issue?
Any other ideas?
I tried searching but it seems my keywords did not give me any good hits. |
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| net_weasel |
| Did you ever find out what was causing your surging? I have the same issue. Only from off idle does it surge. |
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| Lightninrod |
I would suspect a vacuum leak; cracked rubber vacuum line(s), loose line(s), etc.
Dan |
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| net_weasel |
| This is a intermittant problem. Only with hard aceleration from a dead stop. Once the rpms pick up or kicking in passing gear on highway there is no issue. It seems to be only at lower rpms less than 2k. I have check and there are no codes with the onboard computer. I will check the vacuum lines. Although I cant hear a leak. |
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| wa4qfy |
Well I just happen to taken the MO in to the dealership today. After having it all day long they said they could not reproduce the problem.
I think the description here and the one I gave to the service adviser was too specific, and not totally accurate as it did happen at other speeds, but mostly at the lower end of the RPM.
So this afternoon I went over to the shop and I drove the shop foreman out around the dealership. At first I could just barely reproduce the issue, I was thinking it was because the CVT/engine was warm and they had driven it trying to reproduce the issue. I ended up taking a side street and did not realize it dumped out on to a freeway, but MO was still was not failing. So I was getting really ticked (at the MO), it was not doing it for me. Anyway the foreman told me to take the next exit and circle back and go back to the dealership. So as I was just about to get back on the freeway, bang it did it, and big time at about 30-40+. Now, I wasn't just making it up. Then it turns out on the last piece of feeder before turning into the dealership it did it again, and that was from taking off from a dead stop turning right.
Sooooo, we will see tomorrow what the verdict was. I think it's the CVT, but I ain't no mechanic so I will leave it to the trained.
I guess it could be a vacuum line that might have come off. But with it only 2 years old on only about 37K miles, I wouldn't think it would be a cracked line.
Thanks for your suggestion. I will see what they say. |
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| Eric L. |
| Great writeup of doing what needs to done to convince the dealer that there is a problem. Best of luck that the problem is quickly and cheaply resolved. |
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| pacmo |
I was about to start a new thread when I saw this one. I am having a very similar problem of extreme surging under hard acceleration.
With mine however it is when I am traveling at say 20 to 30 and then I hit the accelerator hard (To pass a car or merge with traffic). It will accelerate up normally until it get to 4000 RPM at that point it begins surging fairly violently. The entire car will lurch forward and backward. It wont stop until I lift the accelerator and get the RPM's down. It dose not seem to do it if I accelerate more slowly. The Mo will run fine at RPM's above 4000. You just can't floor it from a relatively slow speed.
Anyone got a clue what is going on here? wa4qfy did you ever get yours resolved? I really hate going to the Steeler. I was hoping this was something I could fix myself. By the way I only have 29K miles on my 05 Mo.
Thanks
Pac |
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| wa4qfy |
| I will post the reason/results as soon as I get my MO back. Hopefully, it should be covered by the 6yr/100k warranty. |
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| hfelknor |
quote:
Originally posted by pacmo
I was about to start a new thread when I saw this one. I am having a very similar problem of extreme surging under hard acceleration.
With mine however it is when I am traveling at say 20 to 30 and then I hit the accelerator hard (To pass a car or merge with traffic). It will accelerate up normally until it get to 4000 RPM at that point it begins surging fairly violently. The entire car will lurch forward and backward. It wont stop until I lift the accelerator and get the RPM's down. It dose not seem to do it if I accelerate more slowly. The Mo will run fine at RPM's above 4000. You just can't floor it from a relatively slow speed.
Anyone got a clue what is going on here? wa4qfy did you ever get yours resolved? I really hate going to the Steeler. I was hoping this was something I could fix myself. By the way I only have 29K miles on my 05 Mo.
Thanks
Pac
Have to wonder if it doesn't have something to do with the throttle position sensor.
Remember the accelerator is not mechanically connected to any thing. In effect it is like a rheostat or potentiometer and if it is defective it could act as you say. wa4qfy too.
But that's nothing more than a SWAG. hard to troubleshoot using the written word........ |
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| Eric L. |
quote:
Originally posted by pacmo
I was about to start a new thread when I saw this one. I am having a very similar problem of extreme surging under hard acceleration.
With mine however it is when I am traveling at say 20 to 30 and then I hit the accelerator hard (To pass a car or merge with traffic). It will accelerate up normally until it get to 4000 RPM at that point it begins surging fairly violently. The entire car will lurch forward and backward. It wont stop until I lift the accelerator and get the RPM's down. It dose not seem to do it if I accelerate more slowly. The Mo will run fine at RPM's above 4000. You just can't floor it from a relatively slow speed.
Anyone got a clue what is going on here? wa4qfy did you ever get yours resolved? I really hate going to the Steeler. I was hoping this was something I could fix myself. By the way I only have 29K miles on my 05 Mo.
Thanks
Pac
At ~4000rpm, a valve opens up in the intake plenum to change the effective intake runner length - it is possible this valve is defective (Nissan calls it a power valve I think). |
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| pacmo |
quote:
Originally posted by Eric L.
At ~4000rpm, a valve opens up in the intake plenum to change the effective intake runner length - it is possible this valve is defective (Nissan calls it a power valve I think).
I am hoping it is something simple like a valve or a vacuum line.
I just hate the idea of taking it to the dealer and telling them you have to floor it at 30 to get it to happen. Just what I need a, dealer kid mechanic, hot dogging my mo around! :3: |
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| wa4qfy |
Well y'all were pretty close turn out that the air intake flow had a leak when I accelerated hard because the torque of the engine flexed the hose and it started sucking air behind the mass air flow sensor. Most likely it was because either the clamps were not tighten up enough or they worked loose.
Pacmo, did you change your airfilter? |
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| pacmo |
quote:
Originally posted by wa4qfy
Well y'all were pretty close turn out that the air intake flow had a leak when I accelerated hard because the torque of the engine flexed the hose and it started sucking air behind the mass air flow sensor. Most likely it was because either the clamps were not tighten up enough or they worked loose.
Pacmo, did you change your airfilter?
wa4qfy you're the man. After seeing your post I immediately went out and checked the intake and sure enough mine is loose and needs to be tightened up. The joint in the red circle on the left is so loose I could pull it apart! I will tighten it up and test it as soon as I can get a screwdriver. I will let you know if it fixed the problem.
I thank you for saving me a trip to the $teeler.
Pac
Update:
I was able to tighten it up on my lunch break and I can say she is running much much better now. Thanks again wa4gfy you're a life saver. :7: |
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| mgthe3 |
ahhhhh
the ole loose intake hose strikes again...
I remember in a post I was helping someone with bucking Mo and knew it was the loose hose because it happened to me --anyway--some other member said it was a fluke because they had never heard of it.
hmmmm
This makes about 6 so far.
Glad you got it fixed. Lurch was the word I was keying on, but, with mine it was so loose it would idle at 200 rpm and buck horribly off the line.
I'd guess you would have to have had a horse buck under you to equate it though, and I have. ;) |
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| net_weasel |
Yes, wa4qfy you are the man! That was exactly the problem.
I checked the wifes MO today. She said the surging was getting worse. This was a recent purchase. It started the day after we bought it.
The MO has 50000 miles on a 05 model. No warranty! The hose on your picture was completly off. The intake hose between the mass air flow sensor and the air duct assembly was just touching. I think it may have been caused by the $teeler detail shop. The engine compartment looked immaculately clean. The protectant they put on all the plastic components was causing it to slide off.
I cleaned the protectant off with solvent so the hose would not slide off again. |
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| net_weasel |
Well... after all that it slide off again. I now removed again and put some spray contact cement on the hose and the plastic housing. I sure hope that does the trick. Time will tell. This is getting very annoying.
I checked for some sort of K&N aftermarket filter/hose. I have seen some of these on other type sport import cars. None is available for the Murano that I can find. I did find a site that had generic fit metal tubing/hose. I may end up getting one of those if this last patch dont work.
If anyone knows of a better fix for this please post. |
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| net_weasel |
It came off again. Even with the contact cement. It looks like the inner most flex hose is corrugated and shrinks in length under hard acceleration. This pulls on the box in the middle causing the hose from the mass air sensor to come off.
Brought it back to the $tealer. Not covered under warranty. A new replacement of the air duct assembly was $126. (part only) The mechanic told me on the test drive that he gets MO's in all the time for this issue. He said they should do a recall but there are none right now. The 2009's have a different setup. Did Nissan know they had a problem? Why change?
I have the fix. Cold Air Intake from K&N. I found one for 40 bucks online. I am sure this will do the trick.
Other than this issue we love the car. |
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| wa4qfy |
quote:
Originally posted by net_weasel
Brought it back to the $tealer. Not covered under warranty. A new replacement of the air duct assembly was $126. (part only) The mechanic told me on the test drive that he gets MO's in all the time for this issue. He said they should do a recall but there are none right now. The 2009's have a different setup. Did Nissan know they had a problem? Why change?
They did not seem to have seen the problem before because I had to go back
and demonstrate the problem with the Shop Foreman before they could find the issue. :confused: |
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| mgthe3 |
quote:
Originally posted by net_weasel
It came off again. Even with the contact cement. It looks like the inner most flex hose is corrugated and shrinks in length under hard acceleration. This pulls on the box in the middle causing the hose from the mass air sensor to come off.
Brought it back to the $tealer. Not covered under warranty. A new replacement of the air duct assembly was $126. (part only) The mechanic told me on the test drive that he gets MO's in all the time for this issue. He said they should do a recall but there are none right now. The 2009's have a different setup. Did Nissan know they had a problem? Why change?
I have the fix. Cold Air Intake from K&N. I found one for 40 bucks online. I am sure this will do the trick.
Other than this issue we love the car.
Mine came off about 5 times I think.
I ended up putting a small sheet metal screw through the hose.
It fixed it permanently.
:D |
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| net_weasel |
| I bought a cold air intake system from K&N. Looks much better than the factory stuff. Adds a lot more room to work on other stuff. Works great, although it did have one bad effect. The new intake is louder than stock. It has a deep rumble at about 2500 RPM's. It supposed to give better gas mileage. I'll keep you posted. |
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