Knocking noise and stalling
 

Morning yall,

I think Ive introduced myself before but its been many years. Anyways, my warranty is going to run out soon and I have a knocking sound coming from under the car. Can be heard better from the passenger side of the car right behind the front tire.

I am going to add some videos and I would appreciate any feedback yall have. In the past few months, the car has stalled when putting it into gear around 10 times, 3 times yesterday as I was trying to back in to my parking spot at work. The dealer had the car for about 6 days, did an air idle relearn and greased the real axles (the TSB job), although I stated a bunch of issues that they even wrote down on the ticket. :shakes head:

I am in a rush so if I left out some details that you think would help, please let me know.

2013 base 370Z 7AT (100% stock) with 99,500 miles on it. I bought the car certified so I have the powertrain warranty for a couple more miles plus I bought a 3rd party platinum warranty that is supposed to cover so many things.

Yes, I did make sure that heat shields and other parts weren't loose.

Thanks in advance for your help!

-James

If for some reason the videos wont work, here is a link and you can find the rest of my videos. https://www.youtube.com/watch?v=vv6wx5ghooY

Could be a cracked flex plate...

Either way I would tow it to the dealer.

Ouch sounded like a diesel, sorry and best of luck, pls keep us posted.

Thanks yall. I'll keep you posted. Hopefully more people will chime in. My car has been at the dealer 3 times since October I think. Last time they had it for about 6 days.

A couple more things, the car drives great except for the noise which I am sure is always there. The rpms sometimes drop to low when i put the car in gear (7AT) and sometimes it stalls.

I know that this is a sports car and i have put over 60k miles on it but lately, the car has been shifting harder (jerky) than usual, especially downshifting. I just went for a drive and had some random misfires but no check engine light.

Get it to a shop asap, before something is really focked up.

Get a piece of garden hose about 4-10 feet long. Start engine. Place one end of the hose to your ear. Move the other end of the hose around until you can pinpoint the source of the noise. May have to lay on ground to check underneath. If you check under the hood, be very careful of moving parts.

Right, but then what? I'm not taking the car apart when it is under two different warranties. I was just trying to get some ideas from people who are more mechanically inclined than I am so i can take some ideas back to the dealership.

Another issue is that when the car warms up, upon take off, it jerks a little like someone learning to drive a manual. Nowhere near as bad bud definitely surge, normal, surge, normal, surge, normal.

I think SouthArk is quite mechanically inclined ;) But it's hard to diagnose off just idling sound taken from a standing position.

If possible, put the car on jack stand, remove the undershroud, then do as SouthArk described. That'll give the seasoned Z guys here a much stronger idea for an internet diagnosis.

If 3x visits to dealership isn't getting this done, it's time roll up the sleeves and dig deeper.

Right on, this will be done tonight. More to come.

It's back at the dealer. Finally got them to say that it sounds like it's the transmission, now they just have to prove it to Nissan.

Once you have identified where the noise is coming from (engine, xmission, differential, etc), those who are more mechanically inclined may be able to provide some help. At this point, everyone is pretty much just shooting in the dark.

Lol so they still can’t/won’t take necessary actions to pinpoint where the sound is coming from, let alone an acute diagnosis, the dealership just wants Nissan to cover a new tranny hoping the problem would be fixed....wow

Best of luck and keep us posted. The 7at and VQ37 are common within the Infiniti lineup, but no Nissan. I wonder if an Infiniti dealership would take a crack at a diagnosis for a fee.

Thanks but I wouldn't necessarily say that. Based on the videos, the stalling, and the other problems I've written in this post, the service manager and one of his employees say that it sounds like the problem is coming from the transmission and I told them that I agreed.

The last time the car was at the dealer, they did an air idle relearn (maybe it's called something different but its 7am and I cant think of it) and did the bulletin for the rear axles clicking. The last guy i dealt with said numerous times that the sound i was hearing sounded like it was coming from the rear of the vehicle and i told him that i did not agree, he even wrote that in the service order.

This time, the service staff said what I am experiencing sounds like a transmission issue, that's all I'm saying. This was never a loose axle issue but I did let them perform the bulletin because I'm sure those axles needed some grease by now.

Now it is up to a mechanic, hopefully with some direction from the service manager, to take a better look at the transmission and if it's not that to figure it out.

I'll keep yall posted.

Ok finally heard back from the dealership. After having my car for about 10 days, they think it's the catalytic Converters because the honeycomb on the inside is breaking apart. That is what they think the rattling noise is. Thoughts?

That happens and it is not uncommon. I think I have one myself about to take a dump. I will find out shortly when the new engine and turbo's get installed.

I really wouldn't think so. Cats going bad would probably throw a CEL, and it's easy to check with a thermometer.

And you can literally bang on them hear loose material.

I'm with SG, sounds like transmission. Maybe flex plate.

Yea man, I'm with yall as well. I mean, people run test pipes and their cars dont stall like mine has been.

I have a feeling that I am going to drop a grand just to take the car back to them.

Now I agree that things break but do you think that this would cause a car to stall when its put into gear? Do you think this would cause random misfires or possibly my clutch slipping? RPMs dropping real low when but into gear?

Yes.
Yes.
Probably not but it may make it feel like it's slipping.
Yes.

When cats fail, they usually cause more restriction in the exhaust flow. This can cause your symptoms (except for slipping clutch).

However, a bad cat should throw a DTC. I don't think it's a cat problem but wouldn't swear to it at this point.

Yea, this is where I am too. Im not positive its a slipping clutch, it could have just been a couple of random misfires. I cant believe the noise in that video could be from a broken honeycomb inside a cat. I will verify with the garden hose idea before I replace anything.

Looks like I will be buying some high flow cats and if this doesn't fix the problem, back to the dealer. I just feel like the noise is coming from in front of the cats. I could be wrong though. Dealer quoted $2200 for them to do it.

I wouldn't start throwing parts at it just yet. Of course, if you plan on getting HFCs in the future, this might be a good time to do it.

It will make things a lot easier if you have a helper when trying to locate where the noise is coming from - one person can move around and listen while the other manipulates the throttle and clutch.

Good luck and be safe.

The dealer has come to the conclusion that its the cats. I found some for around 500. Once I have it on a lift, I will definitely listen to where the noise is coming from before I make the purchase. I have Monday off so that would be a good day for me to do the swap and take it back to the dealer if that doesn't work. I don't have many miles left on my warranty and I still think it is the tranny.

Thanks for the responses.

aren't the cats covered under the warranty? some states have longer warranty on the emission parts than the regular warranty.

you can probably find an used set of cats for less than $200.

Good luck.

I was told 8 years or 80k. I'm at 99k. I'll look into the state thing. The dealer said I should reach out to consumer affairs.

I've got an extra set of cats for way less than $500. And local. If you need them.

Well, since I have not mastered the private message, how about you pm me a price. Depending on what consumer affairs says, and your price of course, I might see you this weekend. These are stock right? Now that I am about to be out of warranty, I'll have to think about what I want to do (high flow vs stock).

I have the dealership flushing my granny right now in hopes that that will lead to them seeing something that isnt normal.

Ahahaha Flushing my granny, oh lord. Anyways, consumer affairs is working with me to replace the cats. If this doesn't fix the problem, they will be sending a tech down to look at my transmission.

I will keep yall posted. Right now, my mind is blown. Right now, I have to say that Nissan has impressed me big time so far. Hopefully they will be able to fix this issue. One thing I can say is, at least they are making an effort.

So the local techs can't tell if it's the cats or the xmission? :shakes head: That's exactly why I avoid dealerships whenever possible.

It is under warranty and while its under warranty, they will be working on it. Besides, where else can I get a loaner car for 3 weeks and not pay for it?

I am wondering which dealer it's at :icon17:

But to be fair Nissan Corporate totally helped me out with airbag work and one of the (previously terrible) local dealerships got it all worked out at no cost to me plus an under warranty steering rack replacement. I couldn't have been happier considering previous experiences at the same dealership under a different service manager.

So now after replacing the catalytic converters (out of warranty) at a $400 cost to me, Nissan covered the rest, they have finally decided to replace the transmission.

I'm glad they are finally addressing what I said the problem was from the beginning. Although I have always planned on keeping this car and probably still will since all these parts have been replaced. At the same time, I wonder if this adds any sale/trade in value.